The Z5U was recommend by a member as having high esr which may be helpful in this situation. The circuit load will be 15 amps i thought a 17 amp transformer appropriate.
Apologies i don't have a scope am doing this on a trial and error basis, approaching one possible suspect at a time. I am investigating.
Any recommendations on the diodes
Thanks.
Apologies i don't have a scope am doing this on a trial and error basis, approaching one possible suspect at a time. I am investigating.
Any recommendations on the diodes
Thanks.
Ok got it, not a bad feature actually using the caps ESR but Z5U have very varying capacitance as the voltage varies over it, but that really is of no issue, so I see the point in using a lossy cap. I take back my criticism. But I'd have some series resistance in addition anyway.
I'd use the diodes you have, just try to add snubbers.
If no scope your approach seems good, taking suspect at a time. Snubbing the rectifiers is a relatively easy test.
9V and 17A...? Is this for audio? Doesnt really matter... Is the buzz you hear in the speakers or the transformer itself? If the transformer is buzzing mechanically, it is due to magnetostriction, and this is due to pulse currents every rectifying cycle. This is worse as the current is high.
Sometimes buzzing gets worse when you have DC currents through the transformer, so a DC blocker may help.
Potting transformers (if they are not from factory) often helps stop the buzzing but over time the vibrations can break the potting and the buzz can come back. Epoxy should sometimes be used carefully because can be too hard. You should let the wires have a little movement so a slightly elastic potting compound is better. I think those wood lacquers made for marine duty are slightly elastic (some are called 'wood skin')
I'd use the diodes you have, just try to add snubbers.
If no scope your approach seems good, taking suspect at a time. Snubbing the rectifiers is a relatively easy test.
9V and 17A...? Is this for audio? Doesnt really matter... Is the buzz you hear in the speakers or the transformer itself? If the transformer is buzzing mechanically, it is due to magnetostriction, and this is due to pulse currents every rectifying cycle. This is worse as the current is high.
Sometimes buzzing gets worse when you have DC currents through the transformer, so a DC blocker may help.
Potting transformers (if they are not from factory) often helps stop the buzzing but over time the vibrations can break the potting and the buzz can come back. Epoxy should sometimes be used carefully because can be too hard. You should let the wires have a little movement so a slightly elastic potting compound is better. I think those wood lacquers made for marine duty are slightly elastic (some are called 'wood skin')