Bridge Rectifier Ground loop fix (seen in Zenv4)

[cmcgraw]

Fellow DIY'ers,

My apologies in advance if this is just another boring grounding question:

I'm building two mono zenv4s, and I'm not sure how to isolate their grounds. I don't really want to shell out $12 for 2 200V 35A bridges, so I'm wondering if there's another (cheaper) solution to isolate the two amps from each other (since I can't use Nelson's bridge trick, cause the channels are in separate cases).

Could I just use 2 diodes (per channel) connected to earth ground (like half a bridge)? And, if so, do they need to be as gigantic as the bridge? I've got a bunch of 400V 1A 1N4004's lying around.

Thanks,
Chris McGraw

[uli]

take a cl60 instead (like in the Alephs)

Uli

[dwjj]

What you need to worry about are fault currents. Think if the primary and secondary shorted in the transformer, or some other fail to induce high voltage/current on the ground connection. You've got to make sure that the ground connection can survive until the fuse blows, until your circuit breaker blows, anything so that your case doesn't become energized.

Using 2 diodes in parallel from the 35A bridge can support a lot of current. That's why he did it that way. I don't think 1A is a safe substitute. Might work to parallel 30 or 50 together?

[joensd]

Originally posted by cmcgraw
Fellow DIY'ers,

My apologies in advance if this is just another boring grounding question:

I'm building two mono zenv4s, and I'm not sure how to isolate their grounds. I don't really want to shell out $12 for 2 200V 35A bridges, so I'm wondering if there's another (cheaper) solution to isolate the two amps from each other (since I can't use Nelson's bridge trick, cause the channels are in separate cases).

Could I just use 2 diodes (per channel) connected to earth ground (like half a bridge)? And, if so, do they need to be as gigantic as the bridge? I've got a bunch of 400V 1A 1N4004's lying around.

Thanks,
Chris McGraw

I can´t give you good advice about alternatives but 12$ for a 200V/35A rectifier seem quite high.
For that price I´d get 7 units at my supplier.
Try to source it elsewhere.

Jens