HT power supply (in progress) - UK Vintage Radio Repair and Restoration Discussion Forum

k_yller · 23rd Aug 2018, 10:02 pm

Some time ago I found that what I need is next HT power supply

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

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

Main parts fitted
front , bottom, top

Diabolical Artificer · 29th Aug 2018, 6:45 am

Nice work, any chance of some schematics?

Andy.

k_yller · 31st Aug 2018, 10:17 pm

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

)

k_yller · 7th Sep 2018, 9:21 pm

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

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

Thanks.

daviddeakin · 14th Sep 2018, 7:59 am

What happens if you short the output? Does it survive?

Skywave · 14th Sep 2018, 7:53 pm

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

Hi
output is fused
diagram with mistake

"0" on front panel is a middle tap of 6.3 V

27th Aug 2018, 6:15 pm	#3
k_yller Pentode Join Date: Jan 2014 Location: Huddersfield, West Yorkshire, UK. Posts: 110	Re: HT power supply (in progress) Main parts fitted front , bottom, top Attached Thumbnails

29th Aug 2018, 6:45 am	#4
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 3,980	Re: HT power supply (in progress) Nice work, any chance of some schematics? Andy. __________________ Curiosity hasn't killed this cat...so far.

31st Aug 2018, 10:17 pm	#5
k_yller Pentode Join Date: Jan 2014 Location: Huddersfield, West Yorkshire, UK. Posts: 110	Re: HT power supply (in progress) 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 ) Attached Thumbnails

7th Sep 2018, 9:21 pm	#6
k_yller Pentode Join Date: Jan 2014 Location: Huddersfield, West Yorkshire, UK. Posts: 110	Re: HT power supply (in progress) 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 Attached Thumbnails

9th Sep 2018, 10:04 pm	#7
k_yller Pentode Join Date: Jan 2014 Location: Huddersfield, West Yorkshire, UK. Posts: 110	Re: HT power supply (in progress) As promised-circuit, if anybody interesting I can try explain how to calculate it it for different input/output voltage Attached Thumbnails

23rd Aug 2018, 10:02 pm	#1
k_yller Pentode Join Date: Jan 2014 Location: Huddersfield, West Yorkshire, UK. Posts: 110	HT power supply (in progress) Some time ago I found that what I need is next HT power supply 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 Attached Thumbnails

26th Aug 2018, 12:37 am	#2
k_yller Pentode Join Date: Jan 2014 Location: Huddersfield, West Yorkshire, UK. Posts: 110	Re: HT power supply (in progress) 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. Attached Thumbnails

13th Sep 2018, 3:10 pm	#8
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 3,980	Re: HT power supply (in progress) Thanks. __________________ Curiosity hasn't killed this cat...so far.

14th Sep 2018, 7:59 am	#9
daviddeakin Hexode Join Date: Apr 2007 Location: Lancashire, UK. Posts: 295	Re: HT power supply (in progress) What happens if you short the output? Does it survive?

14th Sep 2018, 7:53 pm	#10
Skywave Dekatron Join Date: Jun 2006 Location: Chard, south Somerset, UK. Posts: 6,133	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. __________________ "Your idea is crazy! But the question is this: is it crazy enough . . . . to be true?" (Niels Bohr) Last edited by Skywave; 14th Sep 2018 at 8:01 pm.

21st Sep 2018, 9:17 pm	#11
k_yller Pentode Join Date: Jan 2014 Location: Huddersfield, West Yorkshire, UK. Posts: 110	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