amplifier with 12v supply - Page 3 - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 12th March 2013, 10:33 AM   #21
diyAudio Member
 
Join Date: Jul 2012
TDA1562, I measured nominal power of 41W @ 14V power supply (would probably be a bit less at 12V), just need to use different capacitors than in most circuits on the internet.
  Reply With Quote
Old 12th March 2013, 10:36 AM   #22
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by Arvis View Post
TDA1562, I measured nominal power of 41W @ 14V power supply......
Prove it.
__________________
regards Andrew T.
  Reply With Quote
Old 12th March 2013, 03:02 PM   #23
diyAudio Member
 
Join Date: Feb 2006
Location: On a hill, in a wooden shack, next to the woods, in Somerset.
Quote:
Originally Posted by JMFahey View Post

I don't know your specific objection to what I said, but I don't like power outputs quoted against distortion. The figure we really want is for unclipped power and the distortion figure above that is largely a function of how much of the sine wave has been sliced off.

Quote:
Originally Posted by JMFahey View Post
but that won't turn a 20W amplifier into a 40W one.
Gains will be modest.
I thought we were trying to find out if we could get 15W using a 12V battery.

Let's do it the other way around. Power = V^2/R and to get 15W from 4 ohms the RMS voltage will be sqrt(60) = 7.746V. Times sqrt(2) for the peaks = 10.95V, or 22V peak to peak. With a bridged amp we have nominally 24V available, so I reckon that is pretty much doable. With a standard output stage we will have to rely on the battery charging to higher than nominal, but for something modern with a charge pump boosting the driver voltages I would have thought it's eminently possible. Whether the losses are quite this low at full current I haven't looked, but I'd be surprised if there weren't something close among TI's offerings.

Then, of course, there is always the possibility of boosting the supply voltage for the whole thing and you can have any power you want. Hence 500W automotive systems ...
  Reply With Quote
Old 12th March 2013, 03:09 PM   #24
diyAudio Member
 
Join Date: Feb 2006
Location: On a hill, in a wooden shack, next to the woods, in Somerset.
Quote:
Originally Posted by AndrewT View Post
Prove it.
I don't think he needs to.

http://www.nxp.com/documents/data_sh...562Q_ST_SD.pdf

Go to page 13, third line down.
  Reply With Quote
Old 12th March 2013, 03:36 PM   #25
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Does "lift supply" shown twice tell you or us that 14.4V is NOT the amplifier supply voltage?
__________________
regards Andrew T.
  Reply With Quote
Old 12th March 2013, 03:59 PM   #26
johnr66 is offline johnr66  United States
diyAudio Member
 
Join Date: Mar 2009
I'm under the assumption that the lift supply in the TDA1562 can only raise the rails temporarily for transients requiring more power. If a continuous waveform is applied, the lift supply is not able to sustain the higher voltage. I could be wrong.

My method to determine amplifier power is to measure the power at just before clipping using a continuous sine wave into a non inductive load resistance. If the amplifier has more than one channel, all channels must be driven and loaded. If the lift supply cannot maintain the higher voltage, it cannot maintain the higher output in a proper amplifier power measurement.

Last edited by johnr66; 12th March 2013 at 04:02 PM.
  Reply With Quote
Old 12th March 2013, 09:00 PM   #27
diyAudio Member
 
Join Date: Feb 2011
surely will not qork with a sqare wave, and the lift capacitrs must be high quality.
most probably the limiting factor would be the RC time.

on the otherhand with audio signals i do not see why should it not work properly.
someone has put quite some effort to pack a full class H amp in a chip.
i would think this effort did not go to waste.
Supposedly the lift capacitors can charge while the output signal is achieveable with the normal supply rails and the caps only kick when the rail is not high enough for the output signal.
so supposedly, at least what i think, the caps have time to charge. question is if the powersupply rail will handle the extra load
  Reply With Quote
Old 13th March 2013, 11:02 AM   #28
diyAudio Member
 
Join Date: Feb 2006
Location: On a hill, in a wooden shack, next to the woods, in Somerset.
I don't see any reason why it shouldn't work continuously at that power and would imagine that, like most of us (and JohnR66), they define power output as continuous at a given frequency. The size of the capacitor at 4700uF would also seem to point to this. (Besides I don't think you would want to try to sell an amp that collapsed after a few seconds of being pushed hard.)

Nor do I see any reason for it not to work with a square wave since all that is happening is that the rails move up in voltage.

It's just a question of efficiency and keeping the chip cool or the heatsink size down (in this case down to something practically achievable). The price you pay is an extra pair of caps. It can otherwise be thought of as just an amp with an on-board DC-DC converter (which will be perfectly able to deliver the current needs)
  Reply With Quote
Old 13th March 2013, 01:32 PM   #29
diyAudio Member
 
Join Date: Feb 2011
I think efficiency is rather good, as its a class H chip.
  Reply With Quote
Old 13th March 2013, 08:30 PM   #30
diyAudio Member
 
Join Date: Mar 2013
ok
how can i have a 13/0/-13 power supply from a 13v battery?
with 0/5A current in +13 and 0/5A in -13 .
  Reply With Quote

Reply


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
A good 12v power supply to run small class D amplifier indoors? chipper Power Supplies 2 16th June 2014 04:57 PM
+12V (10A) and -12V (0.3A) rating supply question iinself Power Supplies 4 4th January 2013 07:04 PM
portable 12v power supply forkfingers Construction Tips 9 10th April 2010 10:27 AM
F2 with 12V supply Ipanema Pass Labs 21 13th February 2008 04:19 AM
12V Power Supply ? samsagaz Power Supplies 10 4th June 2005 06:38 PM


New To Site? Need Help?

All times are GMT. The time now is 03:47 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2