I'm using bench supplies to prototype an amp design, and I'm about ready to move on to the power supply. Plan is 400V B+, 350V drivers, and 250V screens. B+ and screens will each have a simple MOSFET-based series regulator with their own VR tubes for voltage reference, and the driver supply will pull from the B+ with an RC filter. The PT will be set up as full-wave, with a zener string in the center tap connection for bias supply.
I've verified these current draws using an inline ammeter set for DC amps:
When I modeled it out in LTspice, RMS current at each rectifier diode was over 400 mA. So, questions:
Thanks!
I've verified these current draws using an inline ammeter set for DC amps:
- 160 mA plates
- 35 mA screens
- 10 mA drivers
When I modeled it out in LTspice, RMS current at each rectifier diode was over 400 mA. So, questions:
- Which current figure is the correct one for sizing the transformer? IOW, is a transformer like the Antek AS-3T350, rated for 400mA per HV winding, sufficient?
- Which current figure is the correct one for sizing the rectifiers? I'm looking at using a pair of 6DM4A, a diode rated at 200mA continuous.
Thanks!
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Sounds like a good setup. I use 3a rated diodes for most lower current applications, are fairly generic parts (NTE571) that work great along with a snubber right on the diodes.
Use good quality parts (ie fast rise time) for the snubber too, and you’ll be rewarded.
Use good quality parts (ie fast rise time) for the snubber too, and you’ll be rewarded.
Cool, thanks. How would you interpret the current in this situation vis-à-vis transformer ratings? Is a trafo with a 400mA secondary sufficient for this use case?
Also, I'm using tube diodes (TV dampers), rather than solid-state parts. They're rated for 200mA DC current, 1.2A continuous repetitive peak. Are snubbers still useful in that application?
