[sdiy] can a PSU destroy voices chips?

[Jean-Pierre Desrochers]

Sometimes supply regulators in/out pins can get shorted (inside)
and cause a too high level at their output pin.
I saw 7805 regulators going bad outputing there VDC input
(for ex 8-12vdc) at the output pin causing chain reaction...
IC's destroyed..
The solution... I'm about to try it..
just put a transorb in parallel with the regulators output pin
to keep the voltage from going above a certain level.
Like a 17.1 volts breakdown 1.5KE18AG at the output
of a LM7815. If the regulator get in trouble and try
to generate a higher voltage than 17volts the transorb
will short and stay shorted protecting all the sensitive
IC +15v rail. I know.. the regulator could go wild, burn
or whatever.. but LOTS of synth modules will be saved.
In my case I use PowerOne +/-15vdc supplies 'normally' self-protected
and regulated.. but

My 2 cents.
JP



Le 2013-11-19 10:52, Robyn Mayol a écrit :
> Would anyone be able to explain how this failure in the positive
> supply results in the death of those IC's?
> 
> Please :)
> 
> Robyn
> 
> On 19/11/2013, at 4:34 AM, Antonio Tuzzi wrote:
> 
>> pretty scary!
>> I don't want to to think to a similar CATASTROPHIC failure in a MM ... 
>>  (or an OB8)
>> 
>> at
>> 
>> On 18/nov/2013, at 17:33, Paul Schreiber <synth1 at airmail.net> wrote:
>> 
>>> Yes, this is normal.
>>> 
>>> Paul S>
>>> 
>>> 
>>> --- antoniotuzzi at gmail.com wrote:
>>> 
>>> From: Antonio Tuzzi <antoniotuzzi at gmail.com>
>>> To: Synth DIY <synth-diy at dropmix.xs4all.nl>
>>> Subject: [sdiy] can a PSU destroy voices chips?
>>> Date: Mon, 18 Nov 2013 17:24:39 +0100
>>> 
>>> 
>>> 
>>> Question
>>> Is it (A)normal that a bunch a CEM are dead for a failing positive 
>>> rails ?
>>> 
>>> 
>>> Thanks
>>> Antonio
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>> 
>>> 
>> 
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy