QUASI Amplifier for Beginners - Page 65 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 16th June 2012, 09:14 AM   #641
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
There is a limit to the voltage, so adding more outputs will only give more power into a lower impedance.

At some point the driver transistors will not be up to the task. At that point I would probably go to a triple (pre-driver, driver, outputs). I found six pair of outputs into a low impedance gave a circular 'bite' out of a sine-wave in the second and fourth quadrant (classic sign of not enough drive current). Crown uses the triple in most of their amplifiers.
__________________
Candidates for the Darwin Award should not read this author.
  Reply With Quote
Old 16th June 2012, 09:31 AM   #642
yehan is offline yehan  Philippines
diyAudio Member
 
Join Date: Feb 2009
Ok...i think the output power it depend to the,input voltage? Then if you,add,more transistor i think to prevent over heating? Because the output transistor is in parallel,connection so that the power input divided, on how many output transistor have? Am I right?
  Reply With Quote
Old 16th June 2012, 09:46 AM   #643
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
"Ok...i think the output power it depend to the,input voltage?"

The supply voltage.

"Then if you,add,more transistor i think to prevent over heating? Because the output transistor is in parallel,connection so that the power input divided, on how many output transistor have? Am I right? "

Basically, yes.

With good heat sinks you will be able to get roughly 100W per pair of outputs. A Crown DC300A doesn't have real big sinks, so they use four pair of outputs to do 300W/4Ω. They later offered a heat sink up-grade, or you could add fans.

See here for up to 10,000W with the 2N3773.

Simple 100W power amp
__________________
Candidates for the Darwin Award should not read this author.

Last edited by djk; 16th June 2012 at 09:51 AM.
  Reply With Quote
Old 16th June 2012, 09:56 AM   #644
yehan is offline yehan  Philippines
diyAudio Member
 
Join Date: Feb 2009
So what is the maximum rms watts for this amp? You say that 1 pair you get 100 watts? 5'pair you get 500 watts? When i add the transistor 10 pair i get 1000 watts?
  Reply With Quote
Old 16th June 2012, 10:06 AM   #645
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
"So what is the maximum rms watts for this amp? You say that 1 pair you get 100 watts? 5'pair you get 500 watts? When i add the transistor 10 pair i get 1000 watts? "

Sure, but into a lower impedance.

Read the whole thread here:

Simple 100W power amp

And remember, you will have to make the output a triple if driving lower impedance.
__________________
Candidates for the Darwin Award should not read this author.
  Reply With Quote
Old 16th June 2012, 10:31 AM   #646
yehan is offline yehan  Philippines
diyAudio Member
 
Join Date: Feb 2009
The .33 ohm. When i add the transistor 5, over all 10 pair. The .33 ohm. Will change?
  Reply With Quote
Old 16th June 2012, 10:53 AM   #647
yehan is offline yehan  Philippines
diyAudio Member
 
Join Date: Feb 2009
The protect circuit. The 12/24 volts terminal this is connected to output of the amplifier?
  Reply With Quote
Old 16th June 2012, 11:36 AM   #648
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
A single pair for 100W of maximum output power is a bit ambitious, especially if the devices chosen have poor SOAR.
I prefer to use device power rating as a guide to maximum output power.

Pmax ~ {total device power rating} divided by 5 to 6 for BJTs. I use divide by 4 for FETs
A two pair 1943/5200 has a total device rating of 600W. That would indicate a safe and reliable 100W to 120W of maximum power output.
For an 8ohms amplifier that would require a +-50Vdc to +-54Vdc PSU.
For a 4ohms amplifier that would require a +-38Vdc to +-42Vdc PSU.
For a 2ohms amplifier that would require so much output current, that I would not bother entertaining such a nonsensical target.
__________________
regards Andrew T.

Last edited by AndrewT; 16th June 2012 at 11:42 AM.
  Reply With Quote
Old 16th June 2012, 12:58 PM   #649
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
"A single pair for 100W of maximum output power is a bit ambitious, especially if the devices chosen have poor SOAR."

This thread is mainly about the 2N3773, which has 150W SOA at 100V.

http://www.onsemi.com/pub_link/Collateral/2N3773-D.PDF

A MJ15024 only has 100W SOA at 100V.

http://www.onsemi.com/pub_link/Collateral/MJ15022-D.PDF

One pair of 2N3773, 140W/4Ω:

http://www.crownaudio.com/pdf/legacy...spec-sheet.pdf
__________________
Candidates for the Darwin Award should not read this author.

Last edited by djk; 16th June 2012 at 01:02 PM.
  Reply With Quote
Old 16th June 2012, 08:43 PM   #650
yehan is offline yehan  Philippines
diyAudio Member
 
Join Date: Feb 2009
Apex 550 pls give me all the list of component or only where the mylar and ceramic capacitors.. Thank
  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
MOSFET/BJT QUASI AMPLIFIER WITH PROTECT!!! apexaudio Solid State 40 21st November 2012 01:37 PM
A.Holton AV400 using irfp or Quasi mosfet amplifier ? medogrizli Solid State 49 5th November 2011 11:04 PM
How to identify a quasi-complementary amplifier? motbuddy Solid State 8 24th April 2011 11:59 AM
question about quasi nmos500 amplifier schematic? muky006 Pass Labs 3 8th May 2008 09:07 AM
Quasi N30 ClassA amplifier AndrewT Solid State 8 9th January 2008 07:57 PM


New To Site? Need Help?

All times are GMT. The time now is 05:23 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