Amongst items of test kit, the one thing that there never seems to be enough of are power supplies! This one was built many years ago as a simple unregulated supply for a few valves: it is of use for the odd experimental lash-up when a nominal HT of about 250 v.d.c. at a few mA is required and a stabilised, lower HT for things like oscillators. Plus, of course, provision for 6.3v heater supplies. Basically, it was not so much as a 'design to spec' job as "Here's an assortment of useful-looking bits; I need a PSU. What can I put together?"
The main HT is a double-pi capacitive input L-C filter. I suspect that the rect. valve is a GZ34; the markings have come off. But its shaped like a GZ34; pin-outs are as a GZ34 & it behaves like a GZ34; it's a GZ34!
The +100v O/P is derived from a stabilizer valve. Note the switching of the meter, enabling voltage or current to be monitored. It took me quite some time working that arrangement out, using an ordinary DPDT switch.
Al.
The main HT is a double-pi capacitive input L-C filter. I suspect that the rect. valve is a GZ34; the markings have come off. But its shaped like a GZ34; pin-outs are as a GZ34 & it behaves like a GZ34; it's a GZ34!
The +100v O/P is derived from a stabilizer valve. Note the switching of the meter, enabling voltage or current to be monitored. It took me quite some time working that arrangement out, using an ordinary DPDT switch.
Al.
