> On Wed, 25 Oct 2006 17:45:32 +0100, you wrote:
>
>  
>> Hope this counts as PIC, not EE
>>
>> I've seen circuits for very simple, efficient, transformerless,
>> non-isolated power supplies such as
>> http://www.aaroncake.net/circuits/supply5.htm .
>>
>> Would I have a chance of running a very low frequency PIC16 on this
>> type of supply? would i need to stick a 7805 in too? or is it simply
>> too noisy?
>>
>> thanks
>>
>> jon
>>    
>
> You can get a few mA out of circuits like this, so possible to run PICs at normal clock rates,
> obviously you'd use a 5V1 zener instead of 11V.
> You'll want to add a little bit of series R (~100R fusible) to limit inrush current if it's plugged
> in at the top of the cycle.
>
>
>
>  

>
> Mike Harrison wrote:
> > On Wed, 25 Oct 2006 17:45:32 +0100, you wrote:
> >
> >
> >> Hope this counts as PIC, not EE
> >>
> >> I've seen circuits for very simple, efficient, transformerless,
> >> non-isolated power supplies such as
> >> http://www.aaroncake.net/circuits/supply5.htm .
> >>
> >> Would I have a chance of running a very low frequency PIC16 on this
> >> type of supply? would i need to stick a 7805 in too? or is it simply
> >> too noisy?
> >>
> >> thanks
> >>
> >> jon
> >>
> >
> > You can get a few mA out of circuits like this, so possible to run PICs
> at normal clock rates,
> > obviously you'd use a 5V1 zener instead of 11V.
> > You'll want to add a little bit of series R (~100R fusible) to limit
> inrush current if it's plugged
> > in at the top of the cycle.
> >
> >
> >
> >
> I never saw the original post. Please contact me. You have to be careful
> with these, because power line spikes can cream your PS and PIC.
> I have a commercial version of this with all the safeties needed to make
> use of it, supplying 10-15mA for an AC motor control using a PIC12C
> device. Hundreds were made, been in the field working without a single
> failure after 3 years.
>
> --Bob

> Seeing as this is a "commercial" version, I don't suppose you would be
> interested in posting it to the list?
>
> On 10/25/06, Bob Axtell <.....engineerKILLspam@spam@neomailbox.com> wrote:
>  
>> Mike Harrison wrote:
>>    
>>> On Wed, 25 Oct 2006 17:45:32 +0100, you wrote:
>>>
>>>
>>>      
>>>> Hope this counts as PIC, not EE
>>>>
>>>> I've seen circuits for very simple, efficient, transformerless,
>>>> non-isolated power supplies such as
>>>> http://www.aaroncake.net/circuits/supply5.htm .
>>>>
>>>> Would I have a chance of running a very low frequency PIC16 on this
>>>> type of supply? would i need to stick a 7805 in too? or is it simply
>>>> too noisy?
>>>>
>>>> thanks
>>>>
>>>> jon
>>>>
>>>>        
>>> You can get a few mA out of circuits like this, so possible to run PICs
>>>      
>> at normal clock rates,
>>    
>>> obviously you'd use a 5V1 zener instead of 11V.
>>> You'll want to add a little bit of series R (~100R fusible) to limit
>>>      
>> inrush current if it's plugged
>>    
>>> in at the top of the cycle.
>>>
>>>
>>>
>>>
>>>      
>> I never saw the original post. Please contact me. You have to be careful
>> with these, because power line spikes can cream your PS and PIC.
>> I have a commercial version of this with all the safeties needed to make
>> use of it, supplying 10-15mA for an AC motor control using a PIC12C
>> device. Hundreds were made, been in the field working without a single
>> failure after 3 years.
>>
>> --Bob

> On 10/25/06, Bob Axtell <EraseMEengineerspam_OUTTakeThisOuTneomailbox.com> wrote:
>  
>> I. Forse wrote:
>>    
>>> Take a look at www.edn.com/archives/1994/021794/04di2.htm#fig1
>>> this uses a high voltage current regulator from IXYS
>>>
>>>      
>> I think you will not be able to locate these parts anywhere, because
>> these chips didnt hold up.
>> Maxim took a stab at this, too, and then quietly faded away.
>>
>>    
>
> Supertex has some interesting ICs.
>
> I've tested SR036 before and it works fine for its target application.
> 1) Linear IC low current
> http://www.supertex.com/products/selector_guides/107/100
>
> 2) "pseudo switch-mode" for pure AC supply
> http://www.supertex.com/feature_sr03x.html
>
> Regards,
> Xiaofan
>  

> I have posted it before, but I will post it again. Gotta find it...
> I can only tell you that it is driving a small 120VAC 60hz
> gearmotor.
>
> --Bob
>
>
> Shawn Wilton wrote:
>> Seeing as this is a "commercial" version, I don't suppose you would be
>> interested in posting it to the list?

>
> > Wouter said -
>
> > "The other problem with this type of circuit is the voltage on the
> > mains plug after uplugging..."
>
> > A suitably-rated bleeder resistor would fix that
>
> True, but the circuit as shown does not have that resistor, and the text
> that goes with it admits that another resistor is needed. Two key
> components missing in a circuit that has how many - 10 components? That
> does not exactly raise my confidence in the engineering behind the part
> of the circuit that is shown.
>
> Wouter van Ooijen
>
> -- -------------------------------------------
> Van Ooijen Technische Informatica: http://www.voti.nl
> consultancy, development, PICmicro products
> docent Hogeschool van Utrecht: http://www.voti.nl/hvu
>
>

> Thanks everyone for your comments...
>
>
> On 25/10/06, Harold Hallikainen <EraseMEharoldhallikainen.org> wrote:
>  
>> These sort of supplies have a tremendous shock hazard, so be careful!
>> Also, I'd add a resistor in series with the capacitor to limit the current
>> when it's plugged in at a line voltage peak.
>>    
>
> I realise that - but they have a very low part count and are efficient.
>
> On 25/10/06, Mike Harrison <RemoveMEmikeEraseMEEraseMEwhitewing.co.uk> wrote:
>  
>> obviously you'd use a 5V1 zener instead of 11V.
>> You'll want to add a little bit of series R (~100R fusible) to limit inrush current if it's plugged
>> in at the top of the cycle.
>>    
>
> What do you mean fusible? (in the context of a resistor)?
>
> On 25/10/06, Bob Axtell <RemoveMEengineerspam_OUTKILLspamneomailbox.com> wrote:
>  
>> I have posted it before, but I will post it again. Gotta find it...
>> I can only tell you that it is driving a small 120VAC 60hz
>> gearmotor.
>>    
>
> Thanks for the post bob
>
> On 25/10/06, Wouter van Ooijen <RemoveMEwouterTakeThisOuTspamvoti.nl> wrote:
>  
>> The other problem with this type of circuit is the voltage on the mains
>> plug after uplugging...
>>    
>
> This is going to be used for fixed equipment (if I actually get round
> to making it).
>
> On 26/10/06, Charles Rogers <EraseMEcrogersspamspamBeGonetotelcsi.com> wrote:
>  
>> Why don't you try microchip.com.  AN954 might be just what you
>> are looking for.
>>    
>
> Taking a look...
>
> On 26/10/06, Bob Axtell <RemoveMEengineerKILLspamneomailbox.com> wrote:
>  
>> Let me make it very clear: these transformerless designs are
>> dangerous because they operate with exposed lethal voltages.
>> The only reason I did the gig was because it was to be potted
>> in plastic.. and it was.
>>    
>
> The design will be used in plastic cased fixed equipment, and an earth
> is present so I can design the innards in a safe fashion.
>
>
> On 26/10/06, peter green <plugwashSTOPspamspam_OUTp10link.net> wrote:
>  
>>> Unexperienced developers might risk their lives, and even design
>>> hazardous equipment that can risk the end users' lives
>>>      
>> also doesn't transformerless imply not isolated from the mains? mains
>> neutral cannot be depended on to stay at near eath potential!
>>    
>
> In what context do you mean "rely" ? In my houses electricity supply
> (designated TN-S in UK terminology), the neutral and earth are joined
> at the substation (ie the star point of the REC's transformer where
> the neutral originates is grounded). So only in major fault conditions
> can the potential differ much - only due to a break in neutral or
> earth, or a major fault current on the earth causing a voltage drop on
> the earth.
>
>
> Anyway, for everyone's information, the project i'm considering is
> making an intelligent, anticipating room thermostat for my central
> heating. My current electromechanical stat is rubbish in it's
> performance. It's supplied by a 3 core + earth cable - phase, neutral,
> switched live. The neutral is only present to power the anticipator
> resistor.
>
> Of course, I could use a battery to power the pic, and relay to switch
> the mains volts. But that'd annoy me. Batteries need to be changed,
> and unless I put a bunch of effort into circuit and firmware design to
> reduce power consumption then the battery could go flat real quick.
> And when there's mains voltage in the thermostat, why not use it?
>
> I'd plan on using my current thermostat housing, gutting it and
> fitting a new PCB with a VR for the control knob.
>  

>-----Original Message-----
>From: KILLspampiclist-bouncesspamBeGonemit.edu [EraseMEpiclist-bouncesEraseMEmit.edu]
>Sent: 26 October 2006 14:27
>To: Microcontroller discussion list - Public.
>Subject: Re: [PIC] Transformerless power supply
>
>
>Jinx,
>
>On Thu, 26 Oct 2006 11:11:30 +1300, Jinx wrote:
>
>> > That does not exactly raise my confidence in the
>engineering behind
>> > the part of the circuit that is shown
>>
>> "a little knowledge is a dangerous thing" ?
>>
>> A potentially, no pun intended, harmful circuit that raises as many
>> questions (if you know you ask them that is) as it answers.
>
>Indeed, a "Trap for the unwary" - which will catch out those
>who just copy circuits as they are without underestanding
>them, and just expect they
>will be OK.  I've been known to do this (I started out doing
>just that when my age only needed one digit) so I know it
>happens!  :-)  In those days, of
>course, it was in magazine articles, so the amount of
>available material was limited.

> Jinx,
>
> On Thu, 26 Oct 2006 11:11:30 +1300, Jinx wrote:
>
> > > That does not exactly raise my confidence in the
> engineering
> > > behind the part of the circuit that is shown
> >
> > "a little knowledge is a dangerous thing" ?
> >
> > A potentially, no pun intended, harmful circuit
> that raises
> > as many questions (if you know you ask them that
> is) as
> > it answers.
>
> Indeed, a "Trap for the unwary" - which will catch
> out those who just copy circuits as they are without
> underestanding them, and just expect they
> will be OK.  I've been known to do this (I started
> out doing just that when my age only needed one
> digit) so I know it happens!  :-)  In those days, of
>
> course, it was in magazine articles, so the amount
> of available material was limited.
>
> Cheers,
>
>
>
>
> Howard Winter
> St.Albans, England
>
>

> Seeing as this is a "commercial" version, I don't suppose you would be
> interested in posting it to the list?
>
> On 10/25/06, Bob Axtell wrote:
>
>> Mike Harrison wrote:
>>
>>> On Wed, 25 Oct 2006 17:45:32 +0100, you wrote:
>>>
>>>
>>>
>>>> Hope this counts as PIC, not EE
>>>>
>>>> I've seen circuits for very simple, efficient, transformerless,
>>>> non-isolated power supplies such as
>>>> http://www.aaroncake.net/circuits/supply5.htm .
>>>>
>>>> Would I have a chance of running a very low frequency PIC16 on this
>>>> type of supply? would i need to stick a 7805 in too? or is it simply
>>>> too noisy?
>>>>
>>>> thanks
>>>>
>>>> jon
>>>>
>>>>
>>> You can get a few mA out of circuits like this, so possible to run PICs
>>>
>> at normal clock rates,
>>
>>> obviously you'd use a 5V1 zener instead of 11V.
>>> You'll want to add a little bit of series R (~100R fusible) to limit
>>>
>> inrush current if it's plugged
>>
>>> in at the top of the cycle.
>>>
>>>
>>>
>>>
>>>
>> I never saw the original post. Please contact me. You have to be careful
>> with these, because power line spikes can cream your PS and PIC.
>> I have a commercial version of this with all the safeties needed to make
>> use of it, supplying 10-15mA for an AC motor control using a PIC12C
>> device. Hundreds were made, been in the field working without a single
>> failure after 3 years.
>>
>> --Bob