Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Equipment & Tools From test equipment to hand tools

HP Model 712b Regulated Power supply
HP Model 712b Regulated Power supply
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 6th August 2012, 07:29 PM   #1
donnyab is offline donnyab
diyAudio Member
Join Date: May 2011
Default HP Model 712b Regulated Power supply

Any help appreciated. New to tube amps etc.
I am going to try to replicate this power supply but there are a couple of things that are confusing me.
The relevant circuit is on page 22 of the manual.

I noticed that the voltages across the anodes of the series pass tubes seem very high at 1000 volts and ditto for cathode and screen grid at 460v [- drop across 1500 ohm grid resistor] and 685v respectively . [185 of the volts on the screen is provided by selenium rectifier at bottom left of circuit]
How can the voltages applied be so high ?.
The data sheet for the tube has seriously lower maximum ratings at 400 volts max on anode. Is it ok to put such high voltages on plate, cathode and screen as long as voltages differences are within spec in relation to each other ?
  Reply With Quote
Old 6th August 2012, 08:26 PM   #2
Tubologic is offline Tubologic  Belgium
diyAudio Member
Tubologic's Avatar
Join Date: Dec 2004
Location: Brussels
Maximum voltage ratings in data sheets are allways referenced to the cathode of the tube, which in this circuit is not at ground potential. Thus the actual anode voltage in the circuit shown is 500V and the screen voltage is 185V , which are still acceptable for a good quality 6L6 (preferably the GC version which has a higher max.plate ratings of 500V).
  Reply With Quote


HP Model 712b Regulated Power supplyHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
The Well Regulated Power Supply andrea_mori Power Supplies 137 15th September 2017 08:34 AM
Antique tube power supply HP 711A dgta Swap Meet 2 10th April 2012 09:29 AM
Replacing Diodes in Vintage HP Power supply? Zero Cool Power Supplies 6 17th June 2011 06:09 PM
regulated power supply yugaaa Solid State 17 28th January 2003 02:39 PM
regulated power supply yugaaa Solid State 3 17th June 2002 06:22 PM

New To Site? Need Help?

All times are GMT. The time now is 09:27 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio