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-   -   HT power supply (in progress) (https://www.vintage-radio.net/forum/showthread.php?t=149143)

k_yller 23rd Aug 2018 10:02 pm

HT power supply (in progress)
 
3 Attachment(s)
Some time ago I found that what I need is next HT power supply ;D
more compact that my "beaste boys" (20kg weight each) but more powerfull then few tiny I have.
Project
200-400V at 200mA + grid up to 100V +powerfull 6A 6,3 V all totaly independent (floating)
HT part
Valves (2xPL504+EF80+Str85/10)
standard regulator with reference voltage on Str85/10,

Grid Supply
silicon LR8 chip
Support
Support power supply 5V for HT part meters and cooling fan
Voltage mulitplier for EF80
tiny suport power supply for Grid part meters

Transformer #1
180VA with HT winding + tapped 6,3 V winding + 2 V winding (mutliply for EF80 heater) + 2 extra windings 20V and 30V (one will be used for grid meters)
Transformer#2
toroidal transformer for PL504 heaters

Some basic drawings and chassis

k_yller 26th Aug 2018 12:37 am

Re: HT power supply (in progress)
 
5 Attachment(s)
Design based on dimension taken from components from drawer and drawings from internet , but when i get main component (transformer) I found that connectors looks much different then on catalog drawings :-/ and require much more space.
Anyway finally I can design PCB
PCB contain
voltage multiplier for EF80 heater , support 5V PSU for HT meters & cooling fan (LM317), Grid PSU.
LR8 in SMD version because of power dissipation capability, in standard application with 200K log potentiometer. 200K cover range to 100+ volts , logarytmic gives higher precison in low voltage range. Of course the best will be multiturn but I have to buy it.

k_yller 27th Aug 2018 6:15 pm

Re: HT power supply (in progress)
 
3 Attachment(s)
Main parts fitted
front , bottom, top

Diabolical Artificer 29th Aug 2018 6:45 am

Re: HT power supply (in progress)
 
Nice work, any chance of some schematics?

Andy.

k_yller 31st Aug 2018 10:17 pm

Re: HT power supply (in progress)
 
3 Attachment(s)
I will publish schematic with description after final tests.
Right now after manufacturing temporary front panel I run tests of HT part.
(And like usually in such a cases you get bright new ideas how something can be done better or how project can be developed to higher level ;D)

k_yller 7th Sep 2018 9:21 pm

Re: HT power supply (in progress)
 
2 Attachment(s)
ready :-) (with temporary panel)
HT output -fused
Heater output - fused
Grid output - use internal LR8 protection
unfortunetelly chinese meters are unreliable, can't be properly calibrated in full range
diagram soon

k_yller 9th Sep 2018 10:04 pm

Re: HT power supply (in progress)
 
1 Attachment(s)
As promised-circuit,
if anybody interesting I can try explain how to calculate it it for different input/output voltage

Diabolical Artificer 13th Sep 2018 3:10 pm

Re: HT power supply (in progress)
 
Thanks.

daviddeakin 14th Sep 2018 7:59 am

Re: HT power supply (in progress)
 
What happens if you short the output? Does it survive?

Skywave 14th Sep 2018 7:53 pm

Re: HT power supply (in progress)
 
Hmm: well the two PL504 valves will get very hot, that's for sure! I'd fit a fast-acting fuse between the HT O/P and the front panel connector. Simply choose a fuse of appropriate rating. And it might be a good idea to fit an 'HT on/off' switch too. I'd also not connect the 0 v. terminal to ground / chassis - better to leave it floating. (Your cct. diag. shows that 0v. at ground / chassis). Your photo shows that you already have an 0v. / earth terminal for when you definitely do want that 0v. at earth / chassis potential.

Al.

k_yller 21st Sep 2018 9:17 pm

Re: HT power supply (in progress)
 
Hi
output is fused
diagram with mistake :)
"0" on front panel is a middle tap of 6.3 V


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