Heathkit Model PS-4 High Voltage Power Supply: Part 1, First Look And Check Over

[@hestheMaster]

It is older than me so replace all the capacitors. Test the diodes making up the bridge rectifier. Check resistors and tubes. Consult the Heathkit IP-32 for everything ,it's the same power supply , with a slightly different case. YT videos on the IP-32 are easy to find. I always assume the kit was built by an amateur so proceed as such!

[@wouldchuck3619]

Thank you for the advice!! Thank you for watching!!

[@ovi_4]

Hi, thanks for sharing this very nice and informative video alongside other equally interesting ones . Now, here is a puzzle I'm trying to solve: I'm trying to build one of these components from scratch but before doing it I'm trying to understand the transformer requirements since I don't have one yet and the manual simply don't go into any details of it other than the part number which of course a data sheet for it is non existent !. But, I can wind one up no problem since I have the means to do it. Now, looking at the schematic diagram, "in my eyes" some things simply do not add up. As far as I know and learned over the years on a voltage doubler full wave rectifier configuration you can achieve double the voltage but always at the expense of losing half of the input current right ? Now, (according to the manual) the unit claims to be able to deliver a maximum of 400V DC @100mA (continuous current) or 120mA (intermittently). But reading the schematic it seems that the BLU-BLU transformer winding (that is responsible for delivering the B+) delivers 210V AC @ 120mA (which at first "Glantz" is all good and "Dandy") but since it is used in a full wave voltage doubler configuration which implies that you'll automatically lose half of the initial (AC) current after the rectification. So, if what I say is correct then it simply means that the device should only be able to deliver a maximum of 50mA (@400v DC) or less. So I'm thinking, wouldn't that be a "typo" on the schematic and that the BLU_BLU winding in fact delivers around 250mA of continuous current instead of the marked 120mA ? Another "anomaly" I spotted is that, at the WHT-WHT winding (175V AC @15mA) again, considering, it is a half-wave rectification (as far as I can see) how can we have 270V DC after R1 (1K) and @ the same time have another marking saying 230V DC ??? This is really weird. I always thought that for a half-wave rectifier, the voltage after the rectification should be: V peak= Vrms/0.7071 and in this case = 175Vac/0.7071=247.5V "average" minus around 2 volts (the voltage drop across the 2 selenium rectifiers in series) = 246V DC or thereabout. So...I wonder what would be the logical explanation for all of the described above ? I'm now thinking that there might be even more question marks on the schematic that I'm yet to discover. Any help is much appreciated. Thank you.

[@coreyprocyk9078]

That 47uf was probably replacing a 50uf cap.

[@wouldchuck3619]

Thank you for watching!

[@JesusIsLordofMybeing]

.1 amps

[@wouldchuck3619]

Thank you for watching!