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Biggles · 2nd Nov 2005, 1:48 pm

Hi, sometimes connecting a small value ceramic capacitor across (in parallel with) each diode helps. Be aware that the voltage rating on the capacitor should be more than twice the peak voltage available from the transformer winding. The value of the capacitor should be no more than a few thousand pFs. I've seen this done in commercial equipment and seems to cure the problem of "harsh" switching waveforms found with solid state rectifiers. I've just realised something else. Are you using a 1N4001? This is only rated at 50V PIV. Use 1N4007's instead, the poor 1N4001's will be under severe risk of destruction! The set will be dangerous to use in it's current state. Why not use a valve rectifier?!! Hope this helps. Whoops someone has beat me too it.

Biggles.

2nd Nov 2005, 1:48 pm	#4
Biggles Rest in Peace Join Date: Feb 2004 Location: Hexham, Northumberland, UK. Posts: 2,234	Re: Home brew TRF Hi, sometimes connecting a small value ceramic capacitor across (in parallel with) each diode helps. Be aware that the voltage rating on the capacitor should be more than twice the peak voltage available from the transformer winding. The value of the capacitor should be no more than a few thousand pFs. I've seen this done in commercial equipment and seems to cure the problem of "harsh" switching waveforms found with solid state rectifiers. I've just realised something else. Are you using a 1N4001? This is only rated at 50V PIV. Use 1N4007's instead, the poor 1N4001's will be under severe risk of destruction! The set will be dangerous to use in it's current state. Why not use a valve rectifier?!! Hope this helps. Whoops someone has beat me too it. Biggles. Last edited by Biggles; 2nd Nov 2005 at 1:49 pm. Reason: Info already provided by someone else!