Irf540 Amplifier - Page 3 - 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 29th July 2004, 10:55 AM   #21
diyAudio Member
 
Join Date: Oct 2003
Location: The Lab
Has anyone seen any examples of real life IRF 540/9540 amplifiers here on DIYaudio.com? (apart from the ULCA).

I mean amplifiers that are designed to actually work.
  Reply With Quote
Old 29th July 2004, 11:23 AM   #22
diyAudio Member
 
Join Date: Jul 2001
Location: The Netherlands
Hi,

I have posted a IRF540/IRF9540 amp, that uses a new idea of employing current mirrors to use both legs of the diff-pair to drive the VA-stage. Should be here somewhere under a topic named 'new idea' or something like that. It is designed to actually work.. If i'm recall correctly, I once posted a IRF540/IRF9540 disign is a topic called 'cheapest amp possible' or somthing like that....that one should also work..

cheers,
Thijs
  Reply With Quote
Old 29th July 2004, 11:40 AM   #23
sajti is offline sajti  Hungary
diyAudio Member
 
Join Date: Apr 2003
Location: Vác, Hungary
Quote:
Originally posted by Lars Clausen
Has anyone seen any examples of real life IRF 540/9540 amplifiers here on DIYaudio.com? (apart from the ULCA).

I mean amplifiers that are designed to actually work.

Check this page: http://users.otenet.gr/~athsam/#Audio_Power

There are two amplifiers with IRF540/9540

sajti
  Reply With Quote
Old 29th July 2004, 12:21 PM   #24
sonnya is offline sonnya  Denmark
diyAudio Member
 
sonnya's Avatar
 
Join Date: Oct 2001
Location: Denmark
Quote:
Originally posted by Lars Clausen
Has anyone seen any examples of real life IRF 540/9540 amplifiers here on DIYaudio.com? (apart from the ULCA).

I mean amplifiers that are designed to actually work.
Hey lars we did never see the finished amp i guess it was the .. ULCA2 ...

~3 * 3cm.. ??
__________________
Mirand Audio amps and Dac's - http://www.mirand-audio.dk
  Reply With Quote
Old 29th July 2004, 12:29 PM   #25
OliverD is offline OliverD  Germany
diyAudio Member
 
OliverD's Avatar
 
Join Date: Nov 2002
Location: Germany
Quote:
what with this ??
Your output devices have long been obsolete. Don't buy these transistors, you will get fakes. The diode string is the wrong way round.

I have a very simple amplifier for you, which is made from "real" transistors and a opamp input stage. It is a proven, reliable design. It can be scaled up and down as you like...

Click here
  Reply With Quote
Old 1st August 2004, 09:37 AM   #26
diyAudio Member
 
Join Date: Oct 2003
Location: The Lab
SonnyA: You have a really good memory The project is not forgotten, it was the idea of making a good amplifier kit at a really low price. Was the proposed price range some 10$ per ch. in parts?

Now some work has been done with this idea over the past 6 months, and about to overcome the obsticles of high capacitance in the MOSFET's vs. the quest for higher bandwidth. The new idea in the bowl of this project is that you can't successfully forget high performance in the search for low cost. Even if some low cost / low performance solutions has made it over the years.

But why not try to make something better?

The performance has to be there first, and then if the price is reasonable, i think the project has sustainability. That is why the ULCA project is changing into 'high speed / high performance MOSFET amplifier' project instead. Not with so much focus on ULC (Ultra Low Cost), but instead high performance using these incredibly rugged and potentially fast IRF output devices.

To get open and airy reproduction of treble, the ULCA is now turning into a 'ultra wide bandwidth' amplifier combining some of the features described in the ULCA thread. Bandwidth as high as 500.000 Hz (-3dB) is now possible, and fully stable.
Also i think limiting the output power to 50W/100W of the small output devices, is a drawback, so the circuit and PCB in it's new version also allows for use of bigger output devices. Power of 100W/200W is now very easy.

Of course the size of the PCB is now slightly bigger, and also the price also higher than the 10$ per ch. first proposed.

I know to get really high power in a small space, and the highest quality, there is today (IMHO) no way to get around PWM. The state of the art is Class D. But analog amplifiers can still have a place, as they are simple, cheap and fun to play with. And still can give you great performance, at the cost of potent power supplies and nice big heat sinks.

ULCA
  Reply With Quote
Old 1st August 2004, 10:09 AM   #27
diyAudio Member
 
Join Date: Aug 2003
Location: Prague,Czech Republic
Guys, who will send me private mail, get from me schematic of amp with 540 / 9540 - I havn't own pages .
  Reply With Quote
Old 2nd August 2004, 07:52 PM   #28
sonnya is offline sonnya  Denmark
diyAudio Member
 
sonnya's Avatar
 
Join Date: Oct 2001
Location: Denmark


Nice to hear lars.

Maybe we should meet/or talk in the phone..

I agree with you that if we want a good performance we need a little more. But still it should be possible to make a "VW beetle" amp for everyone at resonable price with a good performance...

Maybe not look so much on what is "latin" regarding parts to use. But design an amp with the right parts to get the right performance..

Maybe it should be more like a 3 - 400DKK per channel amp?



Maybe make a joint design?
__________________
Mirand Audio amps and Dac's - http://www.mirand-audio.dk
  Reply With Quote
Old 5th August 2004, 06:43 PM   #29
diyAudio Member
 
Join Date: May 2004
Location: Hertfordshire
The problem with the IRF540 is the relatively high gate drive voltage required at high output currents. You need a gate drive supply 8V beyond the supply rails. Or you end up with an inefficiently used power supply i.e +/-40V supplies to get a +/-30V output swing.
The classic way around this problem is bootstrapping the drive voltage. I have only seen it done to the upper transistor. If you are using a complementary N/P channel pair you need to bootstrap both power MOSFETs.
Here is the BBW amp. Bootstrap Both Ways. Its cousin the ambiamp swings both ways! Its not as good as the blameless but probably better than the gainclone because of the output stage symmetry. It is based on the 1977 Hitachi application note. I have not got around to building it but it simulates OK
Attached Images
File Type: jpg bbw3.jpg (33.5 KB, 803 views)
  Reply With Quote
Old 5th August 2004, 09:38 PM   #30
diyAudio Member
 
Join Date: Aug 2003
Location: Prague,Czech Republic
It's realy prehistory of mosfet amp. Why do you see problem with higher rail voltage for driving of mosfets gates ? Use two low voltage ( you have truth, it must be practicaly about 7 - 8 V higher ), low power supply, connected in series with main supply. All cost approximately 3 - 4 pound for one channel. Is eight pound problem for you ?
  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
IRF540 Amplifier Ermac Solid State 10 1st November 2009 01:21 AM
On IRF540/9540 Hans Olofsson Solid State 40 21st October 2007 07:00 PM
Irf540 ANTHONY2181 Swap Meet 0 15th August 2002 04:39 PM


New To Site? Need Help?

All times are GMT. The time now is 08:29 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