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previous: Tracy Hi I'm working on an ampeg... -- 1/4/2000 8:41 AM

Re: Diodes to ground on output trannie ?

1/4/2000 3:21 PM
kg	Re: Diodes to ground on output trannie ? hello tracy these diodes are protection diodes, which are supposed to conduct and prevent the plates from going negative. They are also there to intentionally short circuit when their PIV is exceeded, which sounds like the scenario you've described. THis can occur from an improper load on the OPT, either open circuit, or greatly mismatched, or even a voltage spike on the mains. you can replace them with three series connected 1n4007's, which will preserve the PIV. don't bother with current balancing resistors in parallel with the diodes--they are unnecessary. Ken

1/4/2000 3:21 PM

Re: Diodes to ground on output trannie ?

hello tracy

these diodes are protection diodes, which are supposed to conduct and prevent the plates from going negative. They are also there to intentionally short circuit when their PIV is exceeded, which sounds like the scenario you've described. THis can occur from an improper load on the OPT, either open circuit, or greatly mismatched, or even a voltage spike on the mains.

you can replace them with three series connected 1n4007's, which will preserve the PIV. don't bother with current balancing resistors in parallel with the diodes--they are unnecessary.

Ken

Replies:

Tracy Re: Protection diodes -- 1/5/2000 9:07 AM