SMPS and tubes

[Vuokko]

Hi!

I have an idea which has bothered me a while. I have been thinking about getting 200-400V adjustable SMPS. Cheap would be nice and adjusting could be done even with trimmer. Use ofcorse would be generating HV for plates 200mA would be enough most cases. Maybe there is some kind of genereal tube SMPS which gives wanted HV and some amps of 6.3VDC. A ready kit would be nice.

The idea is replace heavy transformer with neat little SMPS.

First thing which comes to my mind is isolation. The galvanic isolators for line signal are cheap. And I have some good outputtransformers too. So I can't see at first sight any easy way to kill myself.

Another problem is when I get out 250 - 0 - 250 V from transformer and rectify it with two diodes amplifier works. If I change 0 - 250 and use full wave bridge to rectify I loose the other half of signal. Will this be a problem with SMPS?

tubelab.com was thinking something like this too and many others were too but designs were consider leathall as I searched.

I'm not good with power supplies and I know nothing about SMPSs. The rest of tube amplifier is much undestandable. So please be patient.

Hannu Vuolasaho

[smoking-amp]

100V at 1 amp (+48 and -48) and can be stacked 4 units up to get 400V. $5

However, the voltage regulation is on the 5V output, not the +/- 48V ones, so requires hacking the regulator feedback. (just some resistor changes) Also requires a minimum load for regulation. Maybe some people would be interested in working this mod. out on the forum.

http://www.allelectronics.com/cgi-bi...R_SUPPLY_.html

Don

[nickds1]

I designed a small very high efficiency SMPS originally for nixies, but some have used it for low current tube designs (up to 50mA @ 250V, possibly more).

Nick's MAX 1771 SMPS

This has been built by loads of people - the Eagle files are available on the page, and there is a BOM for both Digikey & Farnell. It is an SMT/SMD project.

Have fun. Another neonixie-l member has produced a built version for those who just want one off the shelf.