[sdiy] BIG PSU ISSUES

[Neil Johnson]

Dan,

What is the voltage across each of the 22-ohm resistors?

Neil


On 13 Aug 2008, at 22:30, Dan Snazelle wrote:

>
> nope
>
> they are 22ohm. just checked.
>
>  NOW i dont know if i should do this BUT IF i move the trimmers all  
> the way up when i have a load, i can get it to around 11.2  
> volts...but without a load this goes up to almost 15 volts
>
> the only thing that might be a problem is I also am running a 6volt  
> regulator straight off of the PSU (but there is no load attached to  
> that)
>
> i am stumped. could it be a busted cap on the  psu?? (of course  
> when i use it to power my modules, it works just fine)
> hmmmm
>
>
>
>
> --------------------------------------------
> check out various dan music at:
>
> http://www.myspace.com/lossnyc
>
>
> http://www.soundclick.com/lossnyc.htm
>
>
> http://www.indie911.com/dan-snazelle
> (or for techno) http://www.myspace.com/snazelle
>
>
> ________________________________
> From: raywilson at comcast.net
> To: subjectivity at hotmail.com; synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] BIG PSU ISSUES
> Date: Wed, 13 Aug 2008 21:19:36 +0000
>
>
> Measure the current draw of the project. Ohm's law is Ohm's law.  
> You must be dropping the 3 volts on the resistors. Are you sure  
> they are only 22 ohms?  To get 3 volts drop across the 22 ohm  
> resistor you need about 136 mA. That sounds way high. Now if they  
> were 220 ohms you would only need 13.6 mA which sounds about right  
> for what you're describing. Check the Rs.
>
> -------------- Original message --------------
> From: Dan Snazelle
>
>>
>> I have a nice powerone supply. its a 12volt or 15 volt +/- volt. I  
>> am running it
>> at 12 volts and without a load i used the trimmers to set it for  
>> 12volts.
>>
>> i think this model can handle at least .5 amps per channel. i  
>> think actually .75
>> (in +15/-15 mode it handles less amperage)
>>
>> now when i hook up my current project, which is three giant  
>> breadboards (of
>> mainly CMOS low draw chips) to my STAR breadboard (which is the  
>> PSU hooked up to
>> a breadboard which everything else plugs into with 22r resistors  
>> as fuses), and
>> i take a reading of the VOLTS of my project i get a reading of 9  
>> volts.>
>> My questions
>>
>> 1. there are trimmers on the PSU to push it back up to almost 12  
>> volts post
>> load..should i do this? or are the trimmers only for PRE LOAD?
>
>> 2. how can i get around this? could my PSU be messed up?
>>
>> 3. i know these are low amp chips. i only have ONE led on the  
>> entire project.
>> there are some opamps.
>> is load voltage not the same? do i not need to worry? or should i  
>> get a measured
>> 12 volts? and -12 volts?
>>
>>
>> thanks so much
>>
>>
>>
>>
>>
>>
>>
>> --------------------------------------------
>> check out various dan music at:
>>
>> http://www.myspace.com/lossnyc
>>
>>
>> http://www.soundclick.com/lossnyc.htm
>>
>>
>> http://www.indie911.com/dan-snazelle
>> (or for techno) http://www.myspace.com/snazelle
>>
>>
>>> From: philip.macphail at ntlworld.com
>>> To: neil.johnson97 at ntlworld.com; synth-diy at dropmix.xs4all.nl
>>> Subject: Re: [sdiy] Another SSM2164 question
>>> Date: Wed, 13 Aug 2008 21:49:04
> +0100
>>> CC:
>>>
>>>>>
>>>>
>>>> Thanks, and cheers. Now working on schematic entry and then a PCB.
>>>> Thanks to an A3 laser printer from a local Freecycler (who,  
>>>> ironically
>>>> is/was on the list as well - hi Phil!) I can now print out my
>>>> schematics
>>>> BIG!
>>>>
>>>> Neil
>>>> (likes his diagrams in A3)
>>>>
>>>
>>> Hi Neil,
>>> Yes I'm still here, and to add to the irony, I have a half-finished
>>> VCO based on the SSM2164. The shunt R-C networks on the input that
>>> started this thread were a real pain to accommodate with surface- 
>>> mount
>>> components, unless they were put on the back of the board. The  
>>> larger
>>> DIL version would make things much easier.
>>>
>>> Phil (happy with A4 schematics)
>>> ________
> _______________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
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>
>
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