[sdiy] Power supply spike

[ASSI]

On Freitag, 23. Februar 2007 11:14, Louis van Dompselaar wrote:
> The power supply in my modular produces a large spike on the primary
> side when I switch it on so I need to have my monitor speakers
> switched off before I switch the modular on or off otherwise it
> results in a very loud plop.

Big toroid transformer and/or lots of bypass caps on the secondary?  You 
can damp the inrush current with an NTC resistor, but the dimensioning 
and sourcing of those can be tricky.  If the inrush from the 
transformer itself is OK, then you could switch the secondary with some 
delay so the inrush from the bypass caps doesn't add to it.  You can 
also try and soft-start the whole PSU with a dimmer, but you have to 
make sure it's completely bypassed after the soft-start.

> I've seen a lot of mains filters that filter incoming noise, but what
> do I do to keep these spikes from going out?

Most of these filters work both ways.  In your case a large series 
inductance would be beneficial.


Achim.
-- 
+<[Q+ Matrix-12 WAVE#46 Neuron microQkb Andromeda XTk sonic heaven]>+

SD adaptation for Waldorf microQ V2.22R2:
http://Synth.Stromeko.net/Downloads.html#WaldorfSDada