Searching \ for '[PIC]: Artificial Earth regarding switching PSU' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/power/priswitch.htm?key=switching
Search entire site for: 'Artificial Earth regarding switching PSU'.

Exact match. Not showing close matches.
PICList Thread
'[PIC]: Artificial Earth regarding switching PSU'
2002\06\03@185236 by Tal Bejerano - AMC

flavicon
face
Hi 2 All

Are "Artificial Earth" can be made only if you build your switching PSU or
it can be made with other methods?

Regards

Tal Bejerano
AMC - ISRAEL

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.


2002\06\03@234358 by Dave Tweed

face
flavicon
face
Tal --

> Are "Artificial Earth" can be made only if you build your switching PSU or
> it can be made with other methods?

Yes, to get true galvanic isolation you need to generate AC so that you
can push energy through a pair of capacitors (very low-power systems) or
a transformer (most other systems).

The only other option would be a bright light and a photocell -- very
inefficient, but might be useful in certain applications.

-- Dave Tweed

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.


2002\06\04@025939 by Vasile Surducan

flavicon
face
My friend,
I've just made a synchronisation between your last two mails and I have
a thought: never try to supply an analogic power amplifier from a
swithching power supply, you'll be very dissapointed...

best regards, Vasile


On Tue, 4 Jun 2002, Tal Bejerano - AMC wrote:

{Quote hidden}

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email spam_OUTlistservTakeThisOuTspammitvma.mit.edu with SET PICList DIGEST in the body


2002\06\04@030656 by Tal Bejerano - AMC

flavicon
face
Vasile

Please explain what bother you so I can understand what you mean.,,

Regards

Tal Bejerano
AMC - ISRAEL


{Original Message removed}

2002\06\04@032232 by Vasile Surducan

flavicon
face
Me ? Today nothing is bothering me ! the sun is shining, the birds are
singing... ;o)
But your amplifier outputs will be heavy bothered if you'll supply it from
a switching one, mainly because the supply can't follow fast load
current change. As an example a common PC supply has 1 to 2V noise on +5V
line. A small noise on your amplifier input will gave you a lot of
problems.

best, Vasile
http://www.geocities.com/vsurducan


On Tue, 4 Jun 2002, Tal Bejerano - AMC wrote:

> Vasile
>
> Please explain what bother you so I can understand what you mean.,,
>
> Regards
>
> Tal Bejerano
> AMC - ISRAEL
>
>
> {Original Message removed}

2002\06\04@032915 by Tal Bejerano - AMC

flavicon
face
I'm glad the sun is shining and birds flying..:-)

You confuse me...I found a circuit for car preamp and the designer also
design a switching PSU with this "artificial earth" I just wondered if I can
do it other way,

Regards

Tal Bejerano
AMC - ISRAEL


{Original Message removed}

2002\06\04@044348 by Alex Holden

flavicon
face
Dave Tweed wrote:
> The only other option would be a bright light and a photocell -- very
> inefficient, but might be useful in certain applications.

A "quick and dirty" solution could be to couple two small DC motors
together (one driving the other as a dynamo).

--
------------ Alex Holden - http://www.linuxhacker.org ------------
If it doesn't work, you're not hitting it with a big enough hammer

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email .....listservKILLspamspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body


2002\06\04@101008 by M. Adam Davis

flavicon
face
A well designed SMPS should be ok.  You may want to look into the newer
switching regulators that operate in MHz as the output will be easie to
filter than those which operate in the kHz or hundreds of kHz.

Also keep in mind (be accutely aware) that an amplifier has a huge peak
current - your supply can be called on to supply 2-3 times the normal
operating current (and more) for brief instants.  Make certian your
supply can handle that - I suspect that's where most SMPS problems come
from when dealing with amplifiers.

-Adam

Vasile Surducan wrote:

{Quote hidden}

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email .....listservKILLspamspam.....mitvma.mit.edu with SET PICList DIGEST in the body


2002\06\04@115836 by Tal Bejerano - AMC

flavicon
face
I am talking about low current PSU..about 50mA only to supply the OPamp.

Regards

Tal Bejerano
AMC - ISRAEL


{Original Message removed}

2002\06\05@023951 by Vasile Surducan

flavicon
face
Agree Adam !
But you forgot to mention how difficult is to project and built a high
output current, high frequency (MHz) switching power supply...
However, remember how looks the power amplifier output sinusoidal signal
supplied with either a good :-| or a poor :-( switching supply...
best regards,
Vasile

On Tue, 4 Jun 2002, M. Adam Davis wrote:

{Quote hidden}

--
http://www.piclist.com hint: To leave the PICList
@spam@piclist-unsubscribe-requestKILLspamspammitvma.mit.edu


2002\06\05@024209 by Vasile Surducan

flavicon
face
no problem then !

On Tue, 4 Jun 2002, Tal Bejerano - AMC wrote:

> I am talking about low current PSU..about 50mA only to supply the OPamp.
>
> Regards
>
> Tal Bejerano
> AMC - ISRAEL
>
>
> {Original Message removed}

2002\06\05@024845 by Peter L. Peres

picon face
On Tue, 4 Jun 2002, Vasile Surducan wrote:

>My friend,
>I've just made a synchronisation between your last two mails and I have
>a thought: never try to supply an analogic power amplifier from a
>swithching power supply, you'll be very dissapointed...

What about all those manufacturers who design and build home HiFi systems
based on switching PSUs, that include phono amplifiers and microphone and
tape amplifiers, along with AM radios and other delicate items. Not to
mention VCRs (whose audio tape signal level is even lower than a phono
amp's), and who haven't used iron transformers for the last ~12 years or
so.

Peter

--
http://www.piclist.com hint: To leave the PICList
KILLspampiclist-unsubscribe-requestKILLspamspammitvma.mit.edu


2002\06\05@025015 by Peter L. Peres

picon face
On Tue, 4 Jun 2002, Vasile Surducan wrote:

>Me ? Today nothing is bothering me ! the sun is shining, the birds are
>singing... ;o)
>But your amplifier outputs will be heavy bothered if you'll supply it from
>a switching one, mainly because the supply can't follow fast load
>current change. As an example a common PC supply has 1 to 2V noise on +5V
>line. A small noise on your amplifier input will gave you a lot of
>problems.

I don't know what PC supply that was but if I'd say it was badly broken it
would be a major understatement. A PC supply nowadays regulates to 3% (0
to full load - that's 500W sometimes) and has noise well under 50mV (1% of
5V) at full load. And spikes and fuzz on the 5V line are totally TOTALLY
not allowed. This supply goes directly to the CPU secondary psu and the
CPU can cost $1000. You don't want to glitch that. Search the web for a
review/comparison of PC psu's in one of the recent numbers (PC Mag or some
other I do not remember). They give all the figures you want.

Peter

--
http://www.piclist.com hint: To leave the PICList
RemoveMEpiclist-unsubscribe-requestTakeThisOuTspammitvma.mit.edu


2002\06\05@030405 by Vasile Surducan

flavicon
face
Peter, I think he was talking about an automotive system. Maybe you have
right but I don't saw yet a 500W quadro car power amplifier with PSU inside.
But you see, he need only a 50mA artificial earth which is really no
problem.

regards,
Vasile
http://www.geocities.com/vsurducan


On Tue, 4 Jun 2002, Peter L. Peres wrote:

{Quote hidden}

--
http://www.piclist.com hint: To leave the PICList
TakeThisOuTpiclist-unsubscribe-requestEraseMEspamspam_OUTmitvma.mit.edu


2002\06\05@031556 by Vasile Surducan

flavicon
face
Peter, take a good scope and see the +5V on different points on your 1000$
processor + motherboard. You'll be surprised about what they say and what
you'll see ! Usual a poor PC ( 100Mhz to 450 MHz ) have the noise on the
board exactly as I told you ( in the best case is 500mV ). You know
better, there are variants of pentium processors which have local PSU
on the board, with dozens of huge capacitors. Only those have such small
noise as you said and only on small processor voltage ( 2.7 to 3.3V )
We don't talk about the bulshit design of common PSU. Right now I have in
my room about 30 various PC PSU and all are opened for some sort of breackdowns.
Outside, the fence is painted inside the leopard is watching :)
From 10 PSU claimed to know 200W only one is trully 200W, the others are
less than 120W... Let's don't talk anymore about noise because I will be
angry ... ;)


regards,
Vasile
http://www.geocities.com/vsurducan


On Tue, 4 Jun 2002, Peter L. Peres wrote:

{Quote hidden}

--
http://www.piclist.com hint: To leave the PICList
piclist-unsubscribe-requestEraseMEspam.....mitvma.mit.edu


2002\06\05@170548 by Peter L. Peres

picon face
On Wed, 5 Jun 2002, Vasile Surducan wrote:

>Peter, take a good scope and see the +5V on different points on your 1000$
>processor + motherboard. You'll be surprised about what they say and what
>you'll see ! Usual a poor PC ( 100Mhz to 450 MHz ) have the noise on the
>board exactly as I told you ( in the best case is 500mV ). You know
...

PLEASE do look up that PSU comparison on the web. The noise you are seeing
is probably 99% switching noise from the circuits. You did use a
differential probe to measure the noise, yes ? Of course $10 PSUs do not
compete in this game.

Peter

--
http://www.piclist.com hint: To leave the PICList
EraseMEpiclist-unsubscribe-requestspammitvma.mit.edu


More... (looser matching)
- Last day of these posts
- In 2002 , 2003 only
- Today
- New search...