Power Amp P.S. Bleeder Resistor Reg? Power Amp P.S. Bleeder Resistor Reg? - diyAudio
Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

Power Amp P.S. Bleeder Resistor Reg?
Power Amp P.S. Bleeder Resistor Reg?
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 26th April 2008, 11:13 PM   #1
fastcat95 is offline fastcat95  United States
diyAudio Member
Join Date: Jul 2003
Location: Indiana
Default Power Amp P.S. Bleeder Resistor Reg?

Hello to All!

I have read about power amplifier designs with traditional
rectifier/capacitor power supplies that used power resistors
across the large caps to intentionally create a constant load
on the power supply (not the usual bleeder resistor function).
This was done as a way of reducing the power supply voltage fluctuation with current demands from the output stage. Is this
a viable approach that could be added to a power supply to
improve performance, and if so, how great would the constant
load have to be?

Many Thanks In Advance.

  Reply With Quote
Old 27th April 2008, 02:20 PM   #2
AndrewT is offline AndrewT  Scotland
diyAudio Member
Join Date: Jul 2004
Location: Scottish Borders
extra load increases the ripple of the PSU, not reduces fluctuations.
regards Andrew T.
Sent from my desktop computer using a keyboard
  Reply With Quote
Old 28th April 2008, 05:10 AM   #3
gain is offline gain  United States
diyAudio Member
gain's Avatar
Join Date: Apr 2008
YES IT IS A GOOD IDEA! from a safty standpoint its a MUST! a bleeder resistor across a big cap prevents it from storing large amounts of charge for long periods of time. the caps used in the PS's of power amps typically run 4700 - 20000 uF or more. besides being able to maintain the potentially lethal rail voltages across them for days or weeks, capacitors of that size when charged will instantly vaporize any conductive item that happens to fall between its terminals. or it may explode instead, injuring or possibly killing someone who is working on the amp. (this can especially happen when the amp board fails or is disconnected for testing purposes, because then there is no load to discharge the caps when the power is turned off)

please, by all means install bleeder resistors across reservoir capacitors! it may save someone's life someday. use ohm's law and RC time constant to choose a resistor that will totally discharge the cap within about thirty seconds or so after removing power with no load connected to the power supply.
  Reply With Quote


Power Amp P.S. Bleeder Resistor Reg?Hide 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
Bleeder resistor! lanchile Chip Amps 15 24th February 2009 10:06 PM
Best place to place bleeder resistor in a power supply? G Tubes / Valves 13 4th August 2004 09:26 AM
bleeder resistor for ZenV4 power supply; and ancllary matters Zapped Pass Labs 13 24th September 2003 04:02 AM
Bleeder resistor action sam9 Solid State 8 15th May 2003 08:48 PM

New To Site? Need Help?

All times are GMT. The time now is 08:55 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio