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'[EE] DC - AC Conversion ?'
2006\10\31@114838 by Yigit Turgut

picon face
Hello list,

I need to convert12VDC source to 220VAC.

I am not sure which path to follow.
Any ideas ? (I don't want to buy a power inverter)

2006\10\31@115937 by M. Adam Davis

face picon face
How much power do you need?  Is square wave acceptable, or does it
need to be modified sine wave, or pure sine wave?

Is the load a motor, a light, electronics, etc?

The typcial hobbyist cheap and easy method is to use an H bridge to
drive the 12V side of a 220AC/12VAC transformer.

However, if you want to get one amp out of the 220AC side, you'll be
pushing 20 amps into the 12V side (you'll need a 300watt transformer)

Then you can simply use a 555 timer to run the H bridge (which,
remember, has to handle 20 amps)

-Adam

On 10/31/06, Yigit Turgut <spam_OUTy.turgutTakeThisOuTspamgmail.com> wrote:
> Hello list,
>
> I need to convert12VDC source to 220VAC.
>
> I am not sure which path to follow.
> Any ideas ? (I don't want to buy a power inverter)
> -

2006\10\31@115947 by Byron A Jeff

face picon face
On Tue, Oct 31, 2006 at 08:48:30AM -0800, Yigit Turgut wrote:
> Hello list,
>
> I need to convert12VDC source to 220VAC.
>
> I am not sure which path to follow.
> Any ideas ? (I don't want to buy a power inverter)

The above three items are very inconsistent. So please provide
more information:

1) Why do you need to convert 12 VDC to 220 VAC?

2) What maximum current at 220 VAC do you need? What
current capacity at 12 VDC can you provide?

3) Is the equipment sensistive to the type of output
wave generated? i.e. do you need true sine, modified sine,
or will a square wave be sufficient.

4) And of course the most pointed question: Why not buy a
power inverter? It's a device that solves the problem. So
a reason as to why it's not an option would be helpful.

BAJ

2006\10\31@120958 by Yigit Turgut

picon face
Adam,thanx for the reply.

The load is a computer.And I need modified sine wave @ 50hz.

If I can once get into AC,then I know what to do.But I don't know how
to set the frequency.

How can I push 20 amps ? Although I need 5-6 amps.

2006\10\31@121312 by Alan B. Pearce

face picon face
>Any ideas ? (I don't want to buy a power inverter)

It would probably cost a lot less than doing it yourself. An APC UPS is real
cheap for a small unit these days, and could probably be arranged to use
external batteries easily.

2006\10\31@122556 by M. Adam Davis

face picon face
For a 6 amp at 220VAC supply, you'll need a transformer that can
handle 1.5kW  (You need a 15-20% margin since you're not using real
sine waves, and to handle start up surges).

That means your 12V primary is going to be running 125 amps.

Do you have a source of 12V power that can handle 125 amps for any
reasonable length of time?  The transformer alone is going to be more
expensive than a 1500W power inverter.

But assuming you go forward with this, you'll need to build or buy a
220VAC 6A to 12VAC 125A transformer, then build an H bridge that can
handle 125A.

For current requirements this large, usually power inverters run at
24, 36, or 48VDC, so the current requirements in the transformer and H
bridge are lower.  Can you modify your situation so that you can
supply 48VDC input?  Then you'd only need to supply 32A to the 48VAC
side of the transformer, and the H bridge will be easier and cheaper
to build.

Again, you'd be better off building a 12V computer power supply, and
even a 1.5kW car inverter is going to be cheaper than building it
yourself, unless you're raiding a 1.5kW inverter - in which case you'd
be better off fixing it than redesigning it.

-Adam

On 10/31/06, Yigit Turgut <.....y.turgutKILLspamspam@spam@gmail.com> wrote:
> Adam,thanx for the reply.
>
> The load is a computer.And I need modified sine wave @ 50hz.
>
> If I can once get into AC,then I know what to do.But I don't know how
> to set the frequency.
>
> How can I push 20 amps ? Although I need 5-6 amps.
> -

2006\10\31@124945 by Bob Blick

face picon face
On 10/31/06, Yigit Turgut <y.turgutspamKILLspamgmail.com> wrote:
> Hello list,
>
> I need to convert12VDC source to 220VAC.
>
> I am not sure which path to follow.
> Any ideas ? (I don't want to buy a power inverter)

60W inverter = US$10
140W inverter = US$20
2000W inverter = US$200

It will cost more for parts to build your own, unless you already have
most of the parts. And be prepared to fix it at least once or twice, if
you make a simple error when designing it or assembling it.

Do you love to wind transformers? If the answer is yes, then maybe the
extra expense of building your own inverter is worth it. Your typical
inverter today has a ferrite power transformer and one or two ferrite
driver transformers(pulse transformers).

Where are you going to get the transformer cores? Recycling ferrite cores
can be difficult since they are usually glued together. And the efficiency
of a laminated core, low frequency transformer inverter is not great.

Cheerful regards,

Bob



2006\10\31@125202 by Rolf

face picon face
Yigit Turgut wrote:
> Hello list,
>
> I need to convert12VDC source to 220VAC.
>
> I am not sure which path to follow.
> Any ideas ? (I don't want to buy a power inverter)
>  
Buy the inverter... even if you don't want to.... ;-)

If you were in Canada I would tell you to wait a couple of weeks because
CanadianTire regularly puts them on sale, and you can pick up inverters
on sale for about $1 per 10W ($10 for 100W, $20 for 200W, etc...) (when
on sale).

Those prices are hard to beat, honestly.

Rolf

2006\10\31@125739 by Gerhard Fiedler

picon face
Yigit Turgut wrote:

> If I can once get into AC,then I know what to do.But I don't know how to
> set the frequency.

You can use a PIC to control three pins or so. The PIC has a clock, so you
should know how to set the frequency :)

I've never done it or seen it done, but with high currents it may be that
using a transformer with several taps (on the low voltage side) and
switching them individually may be more efficient than feeding the
transformer with a pseudo-sine.

> How can I push 20 amps ?

You don't actually "push" 20 A into the transformer; the transformer
"pulls" them. But you need to control them.

> Although I need 5-6 amps.

Do you need 6 A on the 220 V side? That's a lot of current then on the 12 V
side (120 A).

Gerhard

2006\10\31@130830 by Yigit Turgut

picon face
> The above three items are very inconsistent. So please provide
> more information:
>
> 1) Why do you need to convert 12 VDC to 220 VAC?
>
> 2) What maximum current at 220 VAC do you need? What
> current capacity at 12 VDC can you provide?
>
> 3) Is the equipment sensistive to the type of output
> wave generated? i.e. do you need true sine, modified sine,
> or will a square wave be sufficient.
>
> 4) And of course the most pointed question: Why not buy a
> power inverter? It's a device that solves the problem. So
> a reason as to why it's not an option would be helpful.

Well,money is not an issue,I just want to build my own inverter.

I will be running a pc at my car.So I do need to convert 12VDC to
220VAC.I designed the system such as ;

When car is running between 7000-9000 rpm,energy will be suppilied
directly from the alternator,if not so,energy will be supplied from
the car battery (through inverter)

Modified sine wave seems to be the easy way.

What about Pure Sine Wave ?

2006\10\31@132307 by Bob Blick

face picon face

> Well,money is not an issue,I just want to build my own inverter.
>
> I will be running a pc at my car.So I do need to convert 12VDC to
> 220VAC.I designed the system such as ;

If you are just running the PC you don't need AC. You can do quite well
with 300V DC.

Cheerful regards,

Bob


2006\10\31@133233 by Brady Small

flavicon
face
Why go though all the trouble of converting it, when the computer is never going to use the 220V?

Try this..

http://www.logicsupply.com/product_info.php/products_id/596





{Quote hidden}

> --

2006\10\31@140903 by Shawn Wilton

picon face
Try here:
http://store.mp3car.com/SearchResults.asp?Cat=2

and here:
http://www.mini-box.com/s.nl/sc.8/category.13/.f



On 10/31/06, Brady Small <bradysmallspamspam_OUTbellsouth.net> wrote:
{Quote hidden}

2006\10\31@145303 by alan smith

picon face
"a" computer.  They make 12VDC ATX supplies....for about $50.  For a one-off design pretty much a no brainer unless you just like to experiment.  Rather ineffecient to convert the 12VDC to 220VAC and then convert back to 12VDC/5VDC/3.3VDC as well.
 
 

Yigit Turgut <RemoveMEy.turgutTakeThisOuTspamgmail.com> wrote:
 Adam,thanx for the reply.

The load is a computer.And I need modified sine wave @ 50hz.

If I can once get into AC,then I know what to do.But I don't know how
to set the frequency.

How can I push 20 amps ? Although I need 5-6 amps.

2006\10\31@154358 by Yigit Turgut

picon face
Inverter is necessary because power inverters always leave enough
charge on the battery to run the car.If I run the computer
directly,(without a protection module) the battery may run out and I
may not be able to work the car without an external supply.

2006\10\31@162904 by William Chops Westfield

face picon face

On Oct 31, 2006, at 10:20 AM, Bob Blick wrote:

> If you are just running the PC you don't need AC. You can
> do quite well with 300V DC.

Or less, presumably, since most PCs these days have  "universal"
power supplies designed to operate from 110V OR 220V.

BillW

2006\10\31@170035 by Bob Blick

face picon face
>
> On Oct 31, 2006, at 10:20 AM, Bob Blick wrote:
>
>> If you are just running the PC you don't need AC. You can
>> do quite well with 300V DC.
>
> Or less, presumably, since most PCs these days have  "universal"
> power supplies designed to operate from 110V OR 220V.

No, they pretty much all run on 300 V inside, whether they have a 110-220
switch or do the changeover automatically. The neutral is either put to
one input of a bridge rectifier(220 input) or to the center of the two
series-connected filter capacitors(110 input). The end result is 300 VDC
either way.

BTW, you can get that 300VDC from a DC-AC inverter if you get it before
the output stage(most 110 volt inverters use a hi frequency switcher to
generate + and - 160 volts and then switch it at 60HZ for the output).
That way you can skip the whole 60Hz thing and won't have so much noise,
especially if you are using the PC for audio.

It's only "hot brick" laptop-type supplies that are truly universal input.

Cheers,

Bob


2006\10\31@172009 by Martin Klingensmith

flavicon
face
Think about it, it's much easier to make a protection device to cut off
the 12v supply if the voltage is too low than it is to build a high
power inverter. Think easy and simple not hard like Rube Goldberg.
--
Martin K

Yigit Turgut wrote:
> Inverter is necessary because power inverters always leave enough
> charge on the battery to run the car.If I run the computer
> directly,(without a protection module) the battery may run out and I
> may not be able to work the car without an external supply.
>  


2006\10\31@173205 by M. Adam Davis

face picon face
An inverter can drain a battery just as well as any other power
supply.  It all depends on the design.  Depending on the car the same
inverter may drain one car's battery to the point of not starting, and
drain another's battery but stop with enough left to start the car.

One could readily design their power supply to perform the same function.

However, most car PC conversions include circuitry to have the
computer shut down automatically (and the power supply with it) when
the car's accessory power line goes low.  So it'll only run when the
car is on, or when the key is in the accessory position, the same as
any other device in the car (radio, particularly) that might drain the
battery.  This is actually a better way to go than to simply drain the
battery to a level you think is low enough then shut down.  In bad
conditions it won't be enough.  Depending on how the battery is
drained you'll get a false sense of capacity based on voltage anyway.

Of course you can go the route of building your own inverter.  Chances
are you'll get maybe 80% efficiency.  The computer power supply, if
it's a nice expensive good unit might get as much as 80% efficiency
(many cheap ones are 60% or worse) and you'll end up throwing a huge
amount of energy away.

You'll find a lot of good information on building your own 12V PC
power supply here:
utter.chaos.org.uk/~altman/mp3mobile/#Techie
And here
www.mp3car.com/vbulletin/archive/index.php/f-11.html
And here
www.epanorama.net/links/psu_computer.html#projects
And of course here
http://www.google.com/search?q=car%20pc%20power%20supply%20schematic

And, of course, you can go to http://www.national.com or
http://linear.com or http://maxim-ic.com and use their power supply
designers to make DC-DC switching supplies with minimum fuss.

The reasons you don't see many 12VDC to 120VAC or 220VAC hobbyist
designs are many:
1) "Easy" designs don't support much current (maybe 100 watts)
2) "Easy" high power designs (up to 300W) require huge, heavy,
expensive transformers
3) Good high power designs are non-trivial (anything past 300W)
4) Such power supplies are lethal
5) Only under very strict and rare circumstances will an engineer be
able to design something that is cheaper and suits their application
better than a commercial solution for a one-off project

A PC power supply running from 12V is a much more approachable project
than the inverter, and has much more appeal to the general EE than the
inverter has.  You'll get a lot more help with a DC-DC PC power supply
than with an inverter project.

Unless there's something odd about what you're doing that you haven't
told us, then I believe you'll get more satisfaction out of building a
12VDC PC power supply than you will get out of building your own
inverter.  If you are trying to avoid doing that because you might
blow up your PC, then you don't have enough experience to build an
inverter anyway, and should consider starting with a smaller project.
The inverter will blow up the PC if it's not done well.

-Adam

On 10/31/06, Yigit Turgut <spamBeGoney.turgutspamBeGonespamgmail.com> wrote:
> Inverter is necessary because power inverters always leave enough
> charge on the battery to run the car.If I run the computer
> directly,(without a protection module) the battery may run out and I
> may not be able to work the car without an external supply.
> -

2006\10\31@204128 by Martin K

flavicon
face
Bob,
I have a few new ATX power supplies that have a real PFC input stage and
really are universal input.
--
Martin K

Bob Blick wrote:
{Quote hidden}

2006\10\31@210000 by Bob Blick

face picon face
Martin K wrote:
> Bob,
> I have a few new ATX power supplies that have a real PFC input stage and
> really are universal input.

Oops, you're quite right.

-Bob


'[EE] DC - AC Conversion ?'
2006\11\01@044345 by Alan B. Pearce
face picon face
>I have a few new ATX power supplies that have a real PFC input stage and
>really are universal input.

I would be very surprised if they were done any other way, with modern
switch mode chips available.

2006\11\01@074530 by Dave Lag

picon face
alan smith wrote:
> "a" computer.  They make 12VDC ATX supplies....for about $50.  

Link ?

2006\11\01@075417 by Dave Lag

picon face
Yigit Turgut wrote:

>
> When car is running between 7000-9000 rpm,energy will be suppilied
> directly from the alternator,...

F1 ?
half that maybe...

2006\11\01@080218 by Michael Rigby-Jones

picon face


>-----Original Message-----
>From: TakeThisOuTpiclist-bouncesEraseMEspamspam_OUTmit.edu [RemoveMEpiclist-bouncesspamTakeThisOuTmit.edu]
>Sent: 01 November 2006 12:54
>To: Microcontroller discussion list - Public.
>Subject: Re: [EE] DC - AC Conversion ?
>
>
>Yigit Turgut wrote:
>
>>
>> When car is running between 7000-9000 rpm,energy will be suppilied
>> directly from the alternator,...
>
>F1 ?
>half that maybe...

F1 is MUCH higher than that, 19000 RPM for many of the 2006 cars.  My trusy old Honda rev-limits at ~8200RPM, and the S2000's limiter is up at 9000RPM!

Regards

Mike

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2006\11\01@083704 by Alan B. Pearce

face picon face
>F1 is MUCH higher than that, 19000 RPM for many of the 2006 cars.  My trusy
>old
>Honda rev-limits at ~8200RPM, and the S2000's limiter is up at 9000RPM!

And my Ford Focus Diesel soft limits at 4000 - 4500rpm.

2006\11\01@090322 by Gerhard Fiedler

picon face
Michael Rigby-Jones wrote:

>>Yigit Turgut wrote:
>>>
>>> When car is running between 7000-9000 rpm,energy will be suppilied
>>> directly from the alternator,...
>>
>>F1 ?
>>half that maybe...
>
> F1 is MUCH higher than that, 19000 RPM for many of the 2006 cars.  My
> trusy old Honda rev-limits at ~8200RPM, and the S2000's limiter is up at
> 9000RPM!

The post (and the reply) weren't talking about max rpm, they were talking
about the rpm when the alternator starts to supply the energy rather than
the battery. Which should be a bit lower than the max rpm or you're in
trouble :)

Gerhard

2006\11\01@090446 by Herbert Graf

flavicon
face
On Wed, 2006-11-01 at 09:43 +0000, Alan B. Pearce wrote:
> >I have a few new ATX power supplies that have a real PFC input stage and
> >really are universal input.
>
> I would be very surprised if they were done any other way, with modern
> switch mode chips available.

Most ATX power supplies you buy today on the cheap end do not have any
PFC type front end, at least in Canada.

In the computer industry margins are always razor thin. $1/supply
doesn't seem like very much, but in the world of PC power supplies it
is.

I believe Europe is legislating PFC for switching power supplies, I
don't know the details. TTYL


2006\11\01@100238 by M. Adam Davis

face picon face
Here's a cheap ATX supply schematic:
http://www.pavouk.comp.cz/hw/en_atxps.html

It's 200W ATX, but the 300 and 400 watt supplies are very similar.
The 120VAC is doubled (or the 220/240 is left alone) and then
rectified to about 300VDC.  The switcher then takes that and converts
it and isolates it for the lower voltage needs.  It used to be that
the 12V line was regulated, and the others simply depended on the
transformer windings, but newer supplies may regulate a different
voltage.

-Adam

On 11/1/06, Alan B. Pearce <A.B.PearceEraseMEspam.....rl.ac.uk> wrote:
> >I have a few new ATX power supplies that have a real PFC input stage and
> >really are universal input.
>
> I would be very surprised if they were done any other way, with modern
> switch mode chips available.
>
> -

2006\11\01@114757 by David VanHorn

picon face
On 10/31/06, Yigit Turgut <EraseMEy.turgutspamgmail.com> wrote:
>
> Inverter is necessary because power inverters always leave enough
> charge on the battery to run the car.


Really?  SOME do, some don't.

Honestly, you're fixated on a very expensive and silly path to a solution,
at least by the information you've provided here.

2006\11\01@142927 by Yigit Turgut

picon face
>Unless there's something odd about what you're doing that you haven't
>told us, then I believe you'll get more satisfaction out of building a
>12VDC PC power supply than you will get out of building your own
>inverter.  If you are trying to avoid doing that because you might
>blow up your PC, then you don't have enough experience to build an
>inverter anyway, and should consider starting with a smaller project.
>The inverter will blow up the PC if it's not done well.

I am not trying to avoid that because I might not blow up PC,the
inverter can not blow the PC - that is what a quality power supply is
for.Any malfunctioning at the inverter will effect the power
supply,worst scenario - power supply burns.

>F1 ?
>half that maybe...

Mitsubishi Evolution IX.But since the chip is modified,there is
inconsistency;when NOS is activated alternator peeks (almost two times
its must-be value) and this is going to be a problem if decide to run
the system directly from it.Still working on it.

>Really?  SOME do, some don't.

>Honestly, you're fixated on a very expensive and silly path to a solution,
>at least by the information you've provided here.

Before you talk I suggest you to research first.The worst inverter on
the market under car accesories department has power-cut feature.


Most of the replies till now were irrelevant.Although nice ones come
too.Thanks for all.

Every problem in the nature has an alternative solution.But I want the
AC one. (:

I am still working on theoritical expressions to create the
mathemathical model of the system.

2006\11\01@200439 by M. Adam Davis

face picon face
Good luck!  Let us know what you design, this question comes up
occasionally and it would be great to have a pointer to your work for
future EE car enthusiasts.

-Adam

On 11/1/06, Yigit Turgut <RemoveMEy.turgutEraseMEspamEraseMEgmail.com> wrote:
> I am not trying to avoid that because I might not blow up PC,the
> inverter can not blow the PC - that is what a quality power supply is
> for.Any malfunctioning at the inverter will effect the power
> supply,worst scenario - power supply burns.

You might be surprised. :-)

> Every problem in the nature has an alternative solution.But I want the
> AC one. (:
>
> I am still working on theoritical expressions to create the
> mathemathical model of the system.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - -
Moving in southeast Michigan? Buy my house: http://ubasics.com/house/

Interested in electronics? Check out the projects at http://ubasics.com

Building your own house? Check out http://ubasics.com/home/

2006\11\01@205247 by Shawn Wilton

picon face
It's called google for "carputer".

Or check out this site:  <http://mp3car.com/>

They have a forum with a wealth of information.

Based on the info this guy has given and his responses hither to, it doesn't
sound like her really knows what it is he wants or what he's talking about
(IMHO).  He seems to be deeply confused as to what's involved and what he
needs to do to power this computer in his car.



On 11/1/06, M. Adam Davis <RemoveMEstienmanspam_OUTspamKILLspamgmail.com> wrote:
{Quote hidden}

> -

2006\11\01@223229 by Herbert Graf

flavicon
face
On Wed, 2006-11-01 at 11:29 -0800, Yigit Turgut wrote:
> >Unless there's something odd about what you're doing that you haven't
> >told us, then I believe you'll get more satisfaction out of building a
> >12VDC PC power supply than you will get out of building your own
> >inverter.  If you are trying to avoid doing that because you might
> >blow up your PC, then you don't have enough experience to build an
> >inverter anyway, and should consider starting with a smaller project.
> >The inverter will blow up the PC if it's not done well.
>
> I am not trying to avoid that because I might not blow up PC,the
> inverter can not blow the PC - that is what a quality power supply is
> for.Any malfunctioning at the inverter will effect the power
> supply,worst scenario - power supply burns.

I'm sorry, but no. Even a "quality" PC power supply can be hit with
something that causes MUCH more destruction then just the supply.

> >Really?  SOME do, some don't.
>
> >Honestly, you're fixated on a very expensive and silly path to a solution,
> >at least by the information you've provided here.
>
> Before you talk I suggest you to research first.The worst inverter on
> the market under car accesories department has power-cut feature.

Really? Odd, I have at 1500W inverter that'll drain a battery till it's
dry (learned that the hard way a few times, deep discharging car
batteries is a BAD idea, unless you have a lifetime warranty on
them...). Guess I must just be imagining it sitting on the shelf in
front of me?

>
> Most of the replies till now were irrelevant.Although nice ones come
> too.Thanks for all.
>
> Every problem in the nature has an alternative solution.But I want the
> AC one. (:
>
> I am still working on theoritical expressions to create the
> mathemathical model of the system.

I'm sorry, but considering the task at hand, and your apparent knowledge
of power design you should NOT be surprised that many here don't think
it's a good idea for you to go down this path.

The fact that you can buy an inverter for much less then it'll take to
build one makes these suggestions even more inevitable.

Personally, I'm just hoping you don't hurt yourself. Just remember, it
may only be 12V going it, but the voltages generated inside can EASILY
kill you or someone else. Good luck.

TTYL

2006\11\01@224030 by David VanHorn

picon face
>
> Before you talk I suggest you to research first.The worst inverter on
> the market under car accesories department has power-cut feature.


I own several that have no such feature.

2006\11\01@224851 by David VanHorn

picon face
> I'm sorry, but considering the task at hand, and your apparent knowledge
> of power design you should NOT be surprised that many here don't think
> it's a good idea for you to go down this path.


Why do people fixate like this on THE ONE SOLUTION, when they have competent
people advising them that their solution is unworkable?

I've seen this before when someone, usually from marketing, comes in and
tells us "we need this". It's usually some way off the wall requirement, and
they WILL NOT let go of it despite small objections like that it might defy
the laws of physics, or some other niggling little engineering thing.

"We need 16 bit technology!"  The product was moving packets of a couple
hundred bytes over a 212A modem.. The host was 7E1 and that wouldn't ever
change.

"We need 1M of SRAM in this <$100 product".  At the time, 1M of SRAM cost
about $400 just in chips on the table.  It also was VASTLY more than was
ever needed by the end users.

2006\11\01@233423 by Yigit Turgut

picon face
>I'm sorry, but considering the task at hand, and your apparent knowledge
>of power design you should NOT be surprised that many here don't think
>it's a good idea for you to go down this path.

>The fact that you can buy an inverter for much less then it'll take to
>build one makes these suggestions even more inevitable.

>Personally, I'm just hoping you don't hurt yourself. Just remember, it
>may only be 12V going it, but the voltages generated inside can EASILY
>kill you or someone else. Good luck.


Herbert,this is not the place to discuss this but how much do you know
about my knowledge ? If you have some opinion about it from my
questions and directions,you are watching too much hollywood.

I have an EE major and MBA,If everything goes ok I will be finishing
my Ph.D till the end of 2007.Although you are right,my field is not
power systems.

There are lots of reasons why I seem to be stucked on an inverter.

1)As I said,all of the power inverters (ok,relax,lets just say most of
em) has power-cut feature.This is a good feature to have.Why should I
bother to build an apart module while I am able to handle most of
things in one design.

2)I may be running other stuff (like a printer,digital satellite
reciever[for special purpose] or a wireless booster)

3)It's open for development.You can get almost whatever you want from
city electricity formatted electric without bothering yourself to
design special purposed modules which are going to work only at that
system.

> Why do people fixate like this on THE ONE SOLUTION, when they have competent
> people advising them that their solution is unworkable?

This is what we call thinking wide open.Don't think of this approach
as I don't know what I want - I do.The one solution you are talking
about is going to be roots of another solution for the future.If I
need a refrigrator at my car,what is going to happen ? Another bright
solution will be coming up from competent people ? In time,My car is
going to be full of competent peoples advises because I will be
putting a special module for each thing I want to use.I appreciate
your will to help - I really do but what kind of an investment
philosophy is this ?

2006\11\01@234533 by Peter van Hoof

face picon face
----- Original Message ----
From: David VanHorn <EraseMEdvanhornspamspamspamBeGonemicrobrix.com>
To: Microcontroller discussion list - Public. <RemoveMEpiclistKILLspamspammit.edu>
Sent: Wednesday, November 1, 2006 10:48:50 PM
Subject: Re: Re: [EE] DC - AC Conversion ?


{Quote hidden}

These are just the two ways of learning.
1-learn from the advise, and the experience of others.
2-make all mistakes yourself learn the hard way.

In my experience making all mistakes yourself while sometimes painful, expensive,
stupid etc. does two interesting things.
1-all lessons learned are never again forgotten including the why.
2-most ( all ? ) novel ideas inventions and breakthroughs come from people that do things the
hard way.

Peter van Hoof

"Everything that can be invented has been invented."
Charles H. Duell, Commissioner, U.S. Office of Patentes, 1899

2006\11\02@015321 by Denny Esterline

picon face
> alan smith wrote:
> > "a" computer.  They make 12VDC ATX supplies....for about $50.  
>
> Link ?

Google and 60 seconds later....
http://www.mini-box.com/s.nl/it.A/id.417/.f?sc=8&category=13

-Denny


2006\11\02@025040 by Wouter van Ooijen

face picon face
> "We need 1M of SRAM in this <$100 product".  At the time, 1M
> of SRAM cost
> about $400 just in chips on the table.  It also was VASTLY
> more than was
> ever needed by the end users.

That one can be solved: redefine the meaning of 'b' and give them the
1Mb.

Wouter van Ooijen

-- -------------------------------------------
Van Ooijen Technische Informatica: http://www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: http://www.voti.nl/hvu



2006\11\02@030518 by Shawn Wilton

picon face
On 11/1/06, Yigit Turgut <y.turgutSTOPspamspamspam_OUTgmail.com> wrote:
>
> >I'm sorry, but considering the task at hand, and your apparent knowledge
> >of power design you should NOT be surprised that many here don't think
> >it's a good idea for you to go down this path.
>
> >The fact that you can buy an inverter for much less then it'll take to
> >build one makes these suggestions even more inevitable.
>
> >Personally, I'm just hoping you don't hurt yourself. Just remember, it
> >may only be 12V going it, but the voltages generated inside can EASILY
> >kill you or someone else. Good luck.
>
>
> Herbert,this is not the place to discuss this but how much do you know
> about my knowledge ? If you have some opinion about it from my
> questions and directions,you are watching too much hollywood.



What does Hollywood have to do with this?


I have an EE major and MBA,If everything goes ok I will be finishing
> my Ph.D till the end of 2007.Although you are right,my field is not
> power systems.


Uh huh... I know more PhDs that couldn't engineer their way from a paper
bag.  Amazing how easy it is to get an advanced degree now days. Not to
offend anyone here with an advanced degree... :-P

There are lots of reasons why I seem to be stucked on an inverter.


Lack of knowledge and practicality is #1.

1)As I said,all of the power inverters (ok,relax,lets just say most of
> em) has power-cut feature.This is a good feature to have.Why should I
> bother to build an apart module while I am able to handle most of
> things in one design.


"Power-cut" as you call it, has nothing to do with the inverter.  It's just
a feature.  You can build that feature in to anything you want.  Run a line
from the battery to an ADC on a uC, and cut the enable to a high current
MOSFET and voila, you have "power-cut".  There are many commercial products
available that do this.

2)I may be running other stuff (like a printer,digital satellite
> reciever[for special purpose] or a wireless booster)


... If you need a printer, may I recommend an HP 460C.  It's portable, runs
off 18V (DC), and has a battery pack.  No power inverter required!  Not much
room in an EVO for a DS receiver, but hey, gaudy is almost back in.

3)It's open for development.You can get almost whatever you want from
> city electricity formatted electric without bothering yourself to
> design special purposed modules which are going to work only at that
> system.


Never done any system level engineering...

{Quote hidden}

More like thinking inside a tightly constrained box.  Sorry bud, but you
would be wise to just go pick up a power inverter and be done with it.  If
you're going to run a computer, get a  power supply designed for the
purpose.  It's going to be cheaper than anything you can build.  If you want
to run a computer, run it off DC.  "Everything" except motors run off DC
(some minor exceptions).  If you want a fridge, then use a cheap power
inverter.  Or just go to 7-11 when you need a nice cold drink.

What do you mean by investment philosphy?  Have you bothered to run a power
analysis to see how much power you need?  Are you going to need more
batteries?  More powerful alternator?  How about cabling.  Power losses?
EMI..

Do you have a body kit on your EVO?

Why not tap one of those power professors at your Uni for info on how to
build an inverter.  Google is a useful source too.  OR, you could just go
buy one of those cheap $30 units and reverse engineer it...

The world's your oyster, give it a crack.



-

2006\11\02@113917 by David VanHorn

picon face
>
> That one can be solved: redefine the meaning of 'b' and give them the 1Mb.


Unfortunately, they did say "megabyte".

All the requirements that I mentioned turned out to have no more grounding
than a discussion over drinks.  We had a competitor (tiny) who was using a
16 bit processor for the same application, and so the marketing guys turned
this into "16 bit technology" and decided we needed it.  The job could be
done with a 4 bit processor if it came right down to it, but of course was a
trivial fit for an 8 bitter.

This is what happens when system architecture decisions are made by guys who
send .exe files to ASCII mode printers. (really..)

2006\11\02@135842 by Nate Duehr

face
flavicon
face
David VanHorn wrote:
>> That one can be solved: redefine the meaning of 'b' and give them the 1Mb.
>
>
> Unfortunately, they did say "megabyte".
>
> All the requirements that I mentioned turned out to have no more grounding
> than a discussion over drinks.  We had a competitor (tiny) who was using a
> 16 bit processor for the same application, and so the marketing guys turned
> this into "16 bit technology" and decided we needed it.  The job could be
> done with a 4 bit processor if it came right down to it, but of course was a
> trivial fit for an 8 bitter.
>
> This is what happens when system architecture decisions are made by guys who
> send .exe files to ASCII mode printers. (really..)

I used to get mad about this type of thing, but over the years I
realized that the Marketing folks do sometimes know their business
better than I do, and if they add an "odd" requirement, there's usually
a reason.

Example: I worked for a startup data-center company.  They dictated that
we'd be using Cisco PIX or Checkpoint Firewall-1 for the firewall
solution, period.  The security engineer was pissed - he hadn't even
done an evaluation of any of the various products available to see if
they met the technical requirements, but in the long-run, we realized
that the Marketing people couldn't "sell" anything other than Cisco or
Checkpoint to potential business customer's clueless managers who hadn't
heard of anything else.

Just one of many examples I could provide.  But sometimes the Marketing
"stupidity" is actually them doing their part of the job... figuring out
when they're just full of it and when they're actually helping becomes
an art form in and of itself.

Nate

2006\11\02@141350 by Herbert Graf

flavicon
face
On Wed, 2006-11-01 at 20:34 -0800, Yigit Turgut wrote:
> >I'm sorry, but considering the task at hand, and your apparent knowledge
> >of power design you should NOT be surprised that many here don't think
> >it's a good idea for you to go down this path.
>
> >The fact that you can buy an inverter for much less then it'll take to
> >build one makes these suggestions even more inevitable.
>
> >Personally, I'm just hoping you don't hurt yourself. Just remember, it
> >may only be 12V going it, but the voltages generated inside can EASILY
> >kill you or someone else. Good luck.
>
>
> Herbert,this is not the place to discuss this but how much do you know
> about my knowledge ?

Only what you have presented here.

> If you have some opinion about it from my
> questions and directions,

I am, what else do I have to go on?

> I have an EE major and MBA,If everything goes ok I will be finishing
> my Ph.D till the end of 2007.Although you are right,my field is not
> power systems.

Then it looks like we were right.

Look, there's NOTHING wrong with wanting to learn something. The problem
is taking on too much for a "first" project. Building a 12V-220V
inverter capable of > 1kW is NOT trivial, even for power designers with
SOME experience.

It looks like you are being personally insulted by the people on this
thread, and for that I apologize for my part. But engineering IS about
reevaluating whether a chosen solution is most appropriate, and choosing
this sort of project as a first go isn't what I'd personally recommend.

It does look like you are set in your chosen solution, and on that I
wish you luck. I've given you my opinion and recommendations, whether
you act on them or not is completely up to you. But being personally
insulted when an idea you have is criticized is NOT going to produce
much productive help.

{Quote hidden}

I believe you are talking about the "give a man a fish, he lives for a
day, teach a man to fish he lives till he's old and grey" philosophy?

I COMPLETELY agree with you that "teaching how to fish" is a GREAT way
to go in life. The "but" in this is if you didn't know how to fish, I
wouldn't give you the manual of a 20 million dollar boat and fishing net
setup, give you a 5 minute demo, and set you on your way. I would give
you the fishing reel, the bait, go over a few things and give you some
pointers on catching your own fish. The reason? When you break the
fishing line it's not a big deal. When you crash the 20 million dollar
boat, well, that IS a big deal.

Good luck. TTYL

2006\11\02@151126 by Yigit Turgut

picon face
>> I have an EE major and MBA,If everything goes ok I will be finishing
> > my Ph.D till the end of 2007.Although you are right,my field is not
> > power systems.
>
>
> Uh huh... I know more PhDs that couldn't engineer their way from a paper
> bag.  Amazing how easy it is to get an advanced degree now days. Not to
> offend anyone here with an advanced degree... :-P

I know people who are better than me at the list,also they might be
self-educated,I'm fine with it,np.

Always respect to knowledge

> There are lots of reasons why I seem to be stucked on an inverter.
>
>
> Lack of knowledge and practicality is #1.

Which part you don't understand ?

1)What if I want to use 2 Laptops in my car with different voltage
requirements ? Also a 20" lcd with different voltage ?
2)What if I decide to use a wireless router instead of using the
mini-pci wireless as an ap ?

Aproperiate to run all of them from DC ? I don't want my car to be
mess like my work room.

{Quote hidden}

A DS reciever with its LNB is maximum 3L's volume.You will get some
trouble having the broadcast neatly.

{Quote hidden}

I just want to discuss something with people who knows.Eventually I
will get what I want already.There is nothing wrong with trying
something new.Don't personalize it.

> What do you mean by investment philosphy?  Have you bothered to run a power
> analysis to see how much power you need?  Are you going to need more
> batteries?  More powerful alternator?  How about cabling.  Power losses?
> EMI..

What do you think ? If you read the posts above you would know that I
still did not pick the embedded system that I am searching for up
yet.You were doing just great till the EMI.But hey,don't you worry
right? I am not going to ask any questions.You just take it easy.


> Why not tap one of those power professors at your Uni for info on how to
> build an inverter.  Google is a useful source too.  OR, you could just go
> buy one of those cheap $30 units and reverse engineer it...

Most of them are consisting of  2 or 3 layer pcb.It's hard to reverse
it unless you are not familiar with what you are doing.(gaudy gotta
try right ?)


> The world's your oyster, give it a crack.

Are one of my fans or clients ? Have we met at BlackHAT ' 06 ?

2006\11\02@154911 by Gerhard Fiedler

picon face
> 2-most ( all ? ) novel ideas inventions and breakthroughs come from
> people that do things the hard way.

Is that truly so, or is this more something like a myth?

Gerhard

2006\11\02@155405 by Shawn Wilton

picon face
>
>
>
> Which part you don't understand ?
>
> 1)What if I want to use 2 Laptops in my car with different voltage
> requirements ? Also a 20" lcd with different voltage ?
> 2)What if I decide to use a wireless router instead of using the
> mini-pci wireless as an ap ?


You can plug ANY notebook power adapter in to a standard off the shelf
inverter.

Aproperiate to run all of them from DC ? I don't want my car to be
> mess like my work room.


You didn't mention you just wanted to power a notebook computer.  If you had
said that, most people would have never replied after the first guy said "go
buy a $30 inverter at radio shack".

{Quote hidden}

Your solution (or idea of a solution) is like trying to parallel park an
RV.  Just not a good idea...

{Quote hidden}

Never seen a 3 layer board before.  Not hard to RE either.


> The world's your oyster, give it a crack.
>
> Are one of my fans or clients ? Have we met at BlackHAT ' 06 ?


Huh?  I have no idea who you are beyond this list.

But do yourself a favor and  start by not trying to design a power inverter,
but rather by reverse engineering one you can buy at Walmart, radio shack,
best buy, compusa, etc.

--

Shawn Wilton (b9 Systems)
http://b9Systems.com  <- New web page

2006\11\02@161308 by Gerhard Fiedler

picon face
Yigit Turgut wrote:

> Which part you don't understand ?
>
> 1)What if I want to use 2 Laptops in my car with different voltage
> requirements ? Also a 20" lcd with different voltage ?
> 2)What if I decide to use a wireless router instead of using the
> mini-pci wireless as an ap ?
>
> Aproperiate to run all of them from DC ? I don't want my car to be
> mess like my work room.

You started out asking about how to build an inverter to run one computer.
The thing (at least here, and probably on all lists with qualified people)
is that the responses are as good as the information you give, on average.
You apparently didn't describe your complete scenario: that you are
thinking about running a whole host of devices, from a general household
fridge to a wireless AP, from your inverter.

You might have gotten different answers if you had taken the time to
explain your problem better. Your first message was really too short on
information:

> I need to convert12VDC source to 220VAC.
>
> I am not sure which path to follow.

This is not enough :)  But even after much of the info came over, Herbert's
opinion is probably shared by most: a 1 kW inverter is not really that easy
to design.

So you probably should start researching inverters. You probably find
circuits for lower power devices that help you understand how they work.
You also can find application notes from various semiconductor
manufacturers, maybe even some that address inverters in your power range.
Then you can start designing your own.

If you have any problems on this path, ask questions -- clear questions
about concrete problems. Usually there are people who know the answer or
can point you to a possible one and are willing to help. But something like
the OP of this thread is not enough for receiving good answers. You ask
generic questions, you get generic answers (like "buy an inverter"). You
ask specific questions, you get specific answers (like "use part X for that
purpose" -- but the purpose needs to be specified a bit better than "an
inverter").

Gerhard

2006\11\02@164207 by Yigit Turgut

picon face
>It looks like you are being personally insulted by the people on this
>thread, and for that I apologize for my part. But engineering IS about
>reevaluating whether a chosen solution is most appropriate, and choosing
>this sort of project as a first go isn't what I'd personally recommend.
>
>It does look like you are set in your chosen solution, and on that I
>wish you luck. I've given you my opinion and recommendations, whether
>you act on them or not is completely up to you. But being personally
>insulted when an idea you have is criticized is NOT going to produce
>much productive help

Thank you for your kindness and support Herbert.

It was not my intention to turn this [EE] topic into an [OT] topic.

2006\11\02@164619 by Byron A Jeff

face picon face
On Tue, Oct 31, 2006 at 10:07:52AM -0800, Yigit Turgut wrote:
{Quote hidden}

See why you need to specify the application? Actually no you don't. Every
voltage on a PC is DC and low voltage. So there's absolutely no reason to run
12VDC up to 220 VAC simply to downconvert it back to low DC voltages.

Bob Blick on the list has a design for a multi voltage DC to DC converter
specifically for power a car PC from 12VDC for example.

> When car is running between 7000-9000 rpm,energy will be suppilied
> directly from the alternator,if not so,energy will be supplied from
> the car battery (through inverter)

I've built one of these before. There are more issues:

1) When starting there is often a significant voltage drop.

2) Car power is a frightful place. You're going to need good filtering.

The way that I finally resolved the issue was to insert a 12VDC gel cell
before the DC/DC converter (which I purchased from Marlon P. Jones and
associates surplus store http://www.mpja.com). Then when the car started
the gel cell would carry 12VDC long enough for the PC not to shut down.

>
> Modified sine wave seems to be the easy way.
>
> What about Pure Sine Wave ?

Neither. You need a DC to DC converter. Also 12V powered ATX power supplies
for mini ITX motherboards already exists. Another option is powering a
laptop via a boosted DC voltage.

I spent a lot of time fighting this particular fight. It's really not worth
fighting. The fight is a useful car PC, not providing power for it.

BAJ

2006\11\02@194236 by Howard Winter

face
flavicon
picon face
Herbert,

On Wed, 01 Nov 2006 09:03:36 -0500, Herbert Graf wrote:

{Quote hidden}

I don't know about the rest of Europe, but it was brought in about three years ago here - all PC power supplies have to have PFC now.

Cheers,


Howard Winter
St.Albans, England


2006\11\02@195611 by peter green

flavicon
face
> I don't know about the rest of Europe, but it was brought in
> about three years ago here - all PC power supplies have to have PFC now.
but how many of them actually do?

i strongly suspect many of those in whiteboxes don't comply with the regulations, unless they are checking all imports (which seems very unlikely) then i'm sure the chineese will happilly supply the whitebox vendors in europe with powersupplies that have the european approval stickers on but don't actually comply.


2006\11\02@205408 by Bob Axtell

face picon face
peter green wrote:
>> I don't know about the rest of Europe, but it was brought in
>> about three years ago here - all PC power supplies have to have PFC now.
>>    
> but how many of them actually do?
>
> i strongly suspect many of those in whiteboxes don't comply with the regulations, unless they are checking all imports (which seems very unlikely) then i'm sure the chineese will happilly supply the whitebox vendors in europe with powersupplies that have the european approval stickers on but don't actually comply.
>
>
>  
YES! While checking out a client's wallwart problems, I noticed that two
different wallwarts had identical UL compliance numbers. Upon careful
investigation, we determined that NONE of the wallwarts had good
numbers, the stickers were all bogus. It was an awkward, very lawsuit
moment, as it turned out that even the distributor did NOT know the
stickers were bogus.

Make SURE that chinese-made wallwarts are made safely and have valid
UL/CSA stickers.

--Bob

2006\11\02@205910 by Byron A Jeff

face picon face
On Tue, Oct 31, 2006 at 12:27:58PM -0800, Yigit Turgut wrote:
> Inverter is necessary because power inverters always leave enough
> charge on the battery to run the car.If I run the computer
> directly,(without a protection module) the battery may run out and I
> may not be able to work the car without an external supply.

Orthogonal issues. Nothing inherently about the inverter will cause
it not to draw power from the battery. You can always put a low voltage
cutout on your DC to DC converter so that it turns off the computer
when the battery drops below some certain voltage.

BAJ
> --

2006\11\02@215034 by John Chung

picon face
I really dislike it when the marketing mess with the
engineer decision. Come on keep it simple! Why incur
more cost?! Why use a chip that use more power? Why oh
why? It is like when they say they need a linux box
with LIGHT pc hardware to run a home controller.....
Then they say they cannot sell b'cos it is too
expensive!

John

--- David VanHorn <spamBeGonedvanhornSTOPspamspamEraseMEmicrobrix.com> wrote:

{Quote hidden}

> --

2006\11\02@221206 by Alan B. Pearce

face picon face
>Uh huh... I know more PhDs that couldn't engineer their way from a paper
>bag.  Amazing how easy it is to get an advanced degree now days. Not to
>offend anyone here with an advanced degree... :-P

I still smile that I got my current job with a polytechnic certificate and
30 years experience, over guys with a MEng straight from university.

Not to offend anyone with any degree.

Bu tot come back to what the OP is trying to do - as someone else pointed
out you are way better off to purchase something suitable, unless you
already have the experience to design the unit - in which case you wouldn't
need to ask here. If you are looking to get into that area of expertise,
start with smaller projects, and work up to that.

As an Irishman is reputed to have said - if you want to get there, I
wouldn't start from here.

2006\11\02@224730 by Mike Singer

picon face
Yigit Turgut wrote:

> I am still working on theoretical expressions to
> create the mathematical model of the system.

I'm sure, as PhD you will start with the fundamental concepts,
including the standard big bang picture, inflationary cosmology, dark
matter, perturbations in the cosmic microwave background etc …

MS :-)
.

2006\11\02@232814 by Herbert Graf

flavicon
face
On Fri, 2006-11-03 at 00:42 +0000, Howard Winter wrote:
{Quote hidden}

Wow, I didn't know it was that far along. What about other switching
supplies? Any "banning" of no switcher wall warts like they are doing in
California?

I know here in North America barely anyone KNOWS what PFC correction
is! :(

Thanks for the info.

TTYL

2006\11\02@234813 by William Chops Westfield

face picon face

On Nov 2, 2006, at 5:41 AM, Gerhard Fiedler wrote:

>> 2-most ( all ? ) novel ideas inventions and breakthroughs come from
>> people that do things the hard way.
>
> Is that truly so, or is this more something like a myth?

I think it's clearly true for careful definitions of "novel"...

And of course there are plenty of things that don't yet HAVE an
"easy way", so "the hard way" is the only choice.  I'd expect most
advances to come from this catagory.


I think the original stated task, an ~1000W inverter, is
sufficiently outside the scope of expertise of PIC programming
that you're not going to get useful advice here.  It's not something
you knock off as a small part of your random mobile project, it's
a lucrative field all it's own.  It's more complicated than you
think, and people who know tricks to make it easier probably consider
that info a trade secret and aren't willing to tell you.

BillW

2006\11\03@000459 by olin piclist

face picon face
This is getting silly.  I don't normally respond to general PIC or EE issues
on the PIClist, but I'll make a exception here.  The original question
sounds very much like the same thing asked on the Microchip forum a few days
earlier.  The OP there called himself George Lewis from Alexandria Egypt,
but the questions and attitude are suspiciously similar.  The first question
appeared here on the PIClist shortly after the OP was told pretty much the
same thing on the Microchip forum.

http://forum.microchip.com/tm.aspx?m=198629&mpage=1&key=&#198701

Yigit Turgut wrote:
> Herbert,this is not the place to discuss this but how much do you know
> about my knowledge ? If you have some opinion about it from my
> questions and directions,you are watching too much hollywood.
>
> I have an EE major and MBA,If everything goes ok I will be finishing
> my Ph.D till the end of 2007.Although you are right,my field is not
> power systems.

All the chest puffing aside, you clearly don't know what you're doing in
this area, and this is obvious to anyone reading your posts that does know
what they're doing.

> There are lots of reasons why I seem to be stucked on an inverter.
>
> 1)As I said,all of the power inverters (ok,relax,lets just say most of
> em) has power-cut feature.This is a good feature to have.Why should I
> bother to build an apart module while I am able to handle most of
> things in one design.

Buy you are talking about building your own inverter.  You can add the low
battery cutoff feature to it or any other solution as you want.  This is
therefore not a distinguishing characteristic between a 220V AC inverter or
any other solution.

> 2)I may be running other stuff (like a printer,digital satellite
> reciever[for special purpose] or a wireless booster)

This is the first time you mentioned this specification.  You seem to have
trouble deciding what you want.  Actually I suspect this is more a case of
changing the specs to meet the favored solution.  Unfortunately I see this
too often, especially from inexperienced engineers.  They get emotionally
envolved with whatever solution they came up with first, and world gets
adapted as necessary to fit the solution.

> 3)It's open for development.You can get almost whatever you want from
> city electricity formatted electric without bothering yourself to
> design special purposed modules which are going to work only at that
> system.

So now you're talking about buying a inverter?  I thought you were
stubbornly insisting you wanted to design and build it yourself in previous
posts.

>> Why do people fixate like this on THE ONE SOLUTION, when they have
>> competent people advising them that their solution is unworkable?
>
> This is what we call thinking wide open.

Sounds like a closed mind to me.

> Don't think of this approach
> as I don't know what I want - I do.The one solution you are talking
> about is going to be roots of another solution for the future.If I
> need a refrigrator at my car,what is going to happen ? Another bright
> solution will be coming up from competent people ? In time,My car is
> going to be full of competent peoples advises because I will be
> putting a special module for each thing I want to use.I appreciate
> your will to help - I really do but what kind of an investment
> philosophy is this ?

Now that you've changed the specs to favor a inverter, just go buy one.
Even if you knew what you were doing and spent significant time designing,
testing, and debugging your own inverter, you couldn't build it as cheaply
as you can buy one.  You are in over your head with this, and there is a
reasonable chance you can hurt yourself and others.  This is not a beginner
project in power electronics.

Unless of course you're going for a Darwin award.  If so, by all means build
your own.  That would be the "final solution".


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000.

2006\11\03@030442 by Yigit Turgut

picon face
> > 3)It's open for development.You can get almost whatever you want from
> > city electricity formatted electric without bothering yourself to
> > design special purposed modules which are going to work only at that
> > system.
>
> So now you're talking about buying a inverter?  I thought you were
> stubbornly insisting you wanted to design and build it yourself in previous
> posts.

This is unbelieveable.There I am still talking about building an
inverter,not not to build and buy an inverter.The "special purposed
modules" mentioned in

"you can get almost whatever you want from city electricity formatted
electric without bothering yourself to design special purposed modules
which are going to work only at that system"

this part indicates each DC - DC  conversion made for each equipment.


> >> Why do people fixate like this on THE ONE SOLUTION, when they have
> >> competent people advising them that their solution is unworkable?
> >
> > This is what we call thinking wide open.

I am saying again.Maybe 5th time or so..

This has nothing to do with being emotional.You can pass to almost
anything from city electric -EASILY-.Once you converted 12VDC to
220VAC then you'll have an interface there.You can shape it as much as
you want -WITHOUT MESSÝNG AROUND WITH CABLES OR CIRCUITS.But on the
other hand you will have to convert 12VDC to your equipments required
voltage EACH TIME you want to use an equipment.

> Sounds like a closed mind to me.

Thank you.

> Now that you've changed the specs to favor a inverter, just go buy one.
> Even if you knew what you were doing and spent significant time designing,
> testing, and debugging your own inverter, you couldn't build it as cheaply
> as you can buy one.  You are in over your head with this, and there is a
> reasonable chance you can hurt yourself and others.  This is not a beginner
> project in power electronics.

I leaded and involved lots of projects consisting power electronics.I
am only rusty a bit,need to remeber stuff but things like this
(actually anything,in this case) never give you the right to insult
people or make comments about their way of thinking,behaviour.

I just asked for a comment for a simple problem and things got here.I
guess don't bothering people with theoritcal expressions means that I
don't know what I am doing.LoL.Anyway,there's nothing better than to
follow a strategically designed plan and have a backup-plan.

Strategies are ruling the world.(I'll upload the pictures of my
inverter in the weekend,in case if you are curious about it)

Cheers

2006\11\03@050118 by Howard Winter

face
flavicon
picon face
Herbert,

On Thu, 02 Nov 2006 23:28:11 -0500, Herbert Graf wrote:

>...
> > > I believe Europe is legislating PFC for switching power supplies, I
> > > don't know the details. TTYL
> >
> > I don't know about the rest of Europe, but it was brought in about three years ago here - all PC power supplies have to have PFC now.
>
> Wow, I didn't know it was that far along. What about other switching
> supplies? Any "banning" of no switcher wall warts like they are doing in
> California?

I believe it applies to all electrical appliances above 75W, so fridge/freezers have to have it, but small wall-warts don't.  It's not just things with
switching power supplies, anything with a motor, high-powered fluorescent light fittings, etc. is affected too.  I understand it does apply to the whole
of the EU incidentally, not just Britain, and falls within the CE mark regulations.

> I know here in North America barely anyone KNOWS what PFC correction is! :(

I first encountered it in a factory many years ago where the mains supply was upsetting some of the (Datapoint) computers, so we had someone
come in with a Dranetz mains monitor.  There were occasional 1500V spikes, and it was traced to a PFC device somewhere in the factory supply that
switched capacitors in and out of circuit as machines were turned on and off.  We arranged for separate supplies to be run in for the computers and
all was well.

Cheers,


Howard Winter
St.Albans, England


2006\11\03@082229 by olin piclist

face picon face
Yigit Turgut wrote:
>> "you can get almost whatever you want from city electricity formatted
>> electric without bothering yourself to design special purposed modules
>> which are going to work only at that system"
>
> this part indicates each DC - DC  conversion made for each equipment.

In some variant of english I'm obviously not familiar with.

********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000.

2006\11\03@181137 by Mike Singer

picon face
Yigit Turgut wrote:

> I am still working on theoritical expressions to
> create the mathemathical model of the system

> I guess don't bothering people with theoritcal
> expressions means that I don't know what I am doing.


Yigit,

They wouldn't give PhD to a "theoritcal" guy, because _theoretical_ is
one of the most frequent words for a PhD.
They would say, "it seems like the candidate just doesn't like reading books."

Good luck with PhD,
MS

.

2006\11\03@230019 by M. Adam Davis

face picon face
Don't worry about the naysayers.  All you need to do is repeat what
you said very early in the thread, "Well,money is not an issue,I just
want to build my own inverter."

And to anyone posting that it's too hard, or you could get hurt, or
it's silly, etc you merely need to respond, "Yes, that's probably
true. I just want to build my own inverter."  This is a group of
engineers.  Any attempt to justify your path with technical reasons is
only going to bog you down.

Of course, the downside is that eventually people will stop responding
to your questions simply because this is not the best forum for it.

Let us know how it goes, and what you learn.

-Adam

On 11/3/06, Yigit Turgut <KILLspamy.turgutspamBeGonespamgmail.com> wrote:
{Quote hidden}

>

2006\11\06@092425 by Martin K

flavicon
face
On most cars the alternator spins faster than the engine. The alternator
should be supplying energy to the battery at idle speed, it makes no
sense for it not to (as you imply). For the typical car idling at 1000
RPM, the alternator might be going about 1.5k  - 2k  RPM. I have no idea
where he got the 7k - 9k number, that's ridiculous for anything but a
race car or a rotary engine.
--
Martin K

Gerhard Fiedler wrote:
> The post (and the reply) weren't talking about max rpm, they were talking
> about the rpm when the alternator starts to supply the energy rather than
> the battery. Which should be a bit lower than the max rpm or you're in
> trouble :)
>
> Gerhard
>
>  

2006\11\06@153154 by Howard Winter

face
flavicon
picon face
Martin,

On Mon, 06 Nov 2006 09:26:08 -0500, Martin K wrote:

> On most cars the alternator spins faster than the engine. The alternator
> should be supplying energy to the battery at idle speed,

As I remember it, this was the reason for going over from DC dynamos to Alternators - the commutator on a dynamo limited its speed because of the
sparks it produces, so at low engine speeds it didn't generate enough to charge the battery, which was why the "Ign" light would come on at idle.  
Since alternators use slip rings they can turn faster, so they are "geared" higher by having a smaller pulley, and as you say will generate even at idle.

Cheers,


Howard Winter
St.Albans, England


2006\11\06@162424 by David VanHorn

picon face
On 11/6/06, Martin K <EraseMEmartin-distlistsspamEraseMEnnytech.net> wrote:
>
> On most cars the alternator spins faster than the engine. The alternator
> should be supplying energy to the battery at idle speed, it makes no
> sense for it not to (as you imply). For the typical car idling at 1000
> RPM, the alternator might be going about 1.5k  - 2k  RPM. I have no idea
> where he got the 7k - 9k number, that's ridiculous for anything but a
> race car or a rotary engine.


1500 ish is typical for passenger car idle.  I've set mine as low as 600,
which saves gas pretty nicely.

The alternator absolutely does output plenty at idle.  I've sat for many
hours with AC, lights, strobes, and radios running, and the battery voltage
is still >13V as it should be. And this is a stock passenger car, not a
police model.

2006\11\06@205722 by Howard Winter

face
flavicon
picon face
Dave,

On Mon, 6 Nov 2006 16:24:22 -0500, David VanHorn wrote:

> 1500 ish is typical for passenger car idle.  

Not on any car I've ever driven, it isn't!  :-)  I've never had one idle at even 1000, 500-800 has been the norm.  I did have one that started idling at
1200, but that was because a vacuum pipe had become detached, and it was the ECS's way of saying that something was wrong - it didn't have a
"Check Engine" light or anything so it set the idle revs high as a warning that it wasn't happy.

Cheers,


Howard Winter
St.Albans, England


2006\11\07@042847 by Alan B. Pearce

face picon face
>> 1500 ish is typical for passenger car idle.
>
>Not on any car I've ever driven, it isn't!  :-)

Me too - any car I have owned has always had an idle under 1000 rpm, unless
the choke was pulled out on ones that had manual choke.

I've always regarded around 750 rpm to be normal idle, sometimes it can be
slower on a well tuned engine.

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