Thread: Testing 813's.
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Old 16th Jun 2018, 9:16 am   #1
Diabolical Artificer
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Location: Sleaford, Lincs. UK.
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Default Testing 813's.

I knocked up a 1kV PSU to test some 813's I had, video here - https://www.youtube.com/watch?v=XybEOt6XzXI . I got six good valves out of 7, not bad, as I bought them untested.

One thing I was concerned about is the DC blocking capability of the bridge rectifiers I used and diodes in general. The bridges were GBPC2508's at the high voltage end with jerry rigged bridges made out of 1N4007's at the lower voltage end ( tfmr secs in series, stacked as in attached. As you see he uses 1000V bridges here). The datasheet for the 08's says 800V PIV and DC blocking. I measured 20V ish DC on the winding that fed the "top" bridge, whether this was actual DC or a misreading by my DMM I'm not sure.

If it is DC leakage I'm reading, would putting an EHT diode in series after the bridge and smoothing cap be beneficial? I intend to build a 2500V PSU eventually, this baby HV PSU was by way of a test.

Andy.
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