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

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

power up electronic devices with audio amplifier output
power up electronic devices with audio amplifier output
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
Reply
 
Thread Tools Search this Thread
Old 29th January 2018, 08:30 PM   #21
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
power up electronic devices with audio amplifier output
Well the sort of applications you list are just what variable power supplies are made for. They even have a pot, internal voltage reference, often come with additional features like constant current operation and unflappable output short protection. No need to use an expensive and ill suited audio power amplifier for this task when you can likely buy one or more well suited power supplies for relatively modest money. Topward and several others make good cheap supplies, old HP supplies are often a good bet, rugged and over built, and still working + 20 years on..
__________________
"To argue with a person who has renounced the use of reason is like administering medicine to the dead." - Thomas Paine
  Reply With Quote
Old 30th January 2018, 01:12 AM   #22
Refugee1 is offline Refugee1  United Kingdom
diyAudio Member
 
Refugee1's Avatar
 
Join Date: Jul 2012
Location: Worksop
I once had a look on the web for new speakers but never bought any.
There were quite a few models with lights on the front that flashed to the music. I am pretty sure they just used rectified audio.
  Reply With Quote
Old 30th January 2018, 11:32 AM   #23
Joanito is offline Joanito  Portugal
diyAudio Member
 
Join Date: Mar 2017
Location: Maia, Porto
Hello guys,

"Take your laptop. Suppose you did set up a 100watt amp that runs on -/+50 volt rails to deliver say 19 volts at 4 amps into a laptop.

Think of the heat the amp will dissipate. It would be around 120 watts. Its just not workable."

Yes, it's 105w rms in 4 ohm, but after rectification the value of wattage will increase enough for powering the laptop, right ?

Those speakers with lights flashing to the sound of the music must be cool !
  Reply With Quote
Old 30th January 2018, 11:37 AM   #24
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
power up electronic devices with audio amplifier output
Not exactly...

The laptop would draw whatever current it needed, and that assumes the supply feeding it is at least capable of that current requirement.

If you set an amplifier up to deliver a given output voltage then you need to subtract that voltage from the DC supply rail value in order to get the voltage dropped across the output transistors. Multiplying that voltage by the current drawn will give the power dissipated in the amplifier.

That all assumes a normal class AB type design.
  Reply With Quote
Old 30th January 2018, 12:01 PM   #25
Joanito is offline Joanito  Portugal
diyAudio Member
 
Join Date: Mar 2017
Location: Maia, Porto
ok thanks
  Reply With Quote

Reply


power up electronic devices with audio amplifier outputHide 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
Commercial Audio Brands: N-Ch/NPN only output devices in a push pull power follower tiefbassuebertr Solid State 0 11th May 2011 10:15 AM
fairchild semi, new audio output devices unclejed613 Solid State 85 29th July 2008 06:52 AM
how to mount output devices of amplifier? Wagener Solid State 8 9th April 2004 08:42 AM
Amplifier -adding extra output devices norvbul Solid State 1 30th April 2003 07:10 PM


New To Site? Need Help?

All times are GMT. The time now is 09:40 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki