Zobel filters in power supplies

[carlmart]

Does anyone know how to compute zobel networks for a power supply?

The first time I read about zobels on supplies was on an article on TNT by Dejan V. Veselinovic:

http://www.tnt-audio.com/clinica/ssps2_e.html

The case now is a DC-DC supply which seems to induce a beeping, and I think a zobel might help. Capacitors improve it, particularly low ESR types, but only up to a point.

What I don't know is if there's a way to calculate a zobel on supplies. The zobel formula I have is for speakers, which needs an L figure to get to a final number. What's the L on a supply? Infinite?


Carlos

 

[Piercarlo]

What I don't know is if there's a way to calculate a zobel on supplies. The zobel formula I have is for speakers, which needs an L figure to get to a final number. What's the L on a supply? Infinite?

Carlos [/B]

Don't exist any "true" formula for Zobel (or snubber) networks used in various circuits (i don't know where you have found your "formula" but, at my knowledge, any formula of this kind are essentially hoaxes or, at best, the "formula" of not-have-understood-nothing). The way to find out the values of components is essentially empirical: you must know the energy of nuisance to be attenuated or suppressed; the impedances on the field, the frequiencies (better: the SPEED) of the nuisances occurring in your circuit.
The goal of this kind of network is mainly "catch" (tune) and "kill" (dissipate) the nuisance and it's energy and this twofold task may be solved only on a situational basis, not with "general rules" which can't exist. The difference of approach is near the same that exist between "analytical" and "numeric" solutions in mathematic. The former may have general solution than latter, which usually born and die with the situation that recall it.

Hi
Piercarlo