Class D

Thread Starter

HasRen

Joined Nov 21, 2019
4
I am considering to build a class D amplifier based on Cezar Chirila's article of August 2018. I have few questions: 1) Is there anyone who has built it? 2) How do I access the PCB files both in PDF format and as KiCAD files? I cannot access them by clicking on the Goodies Zip files it logs me out of the website and takes me the forum discussions. 3) What other BJT can I use instead of the BD241C? I cannot find it on KiCAD library.
 

Marley

Joined Apr 4, 2016
311
If I click on the Goodies.zip my browser opens a dialog asking where I want to save the file. Downloaded it and all the files are there!
The BD241C is a common TO220 outline transistor. Choose a similar type with similar specification. Or make you own library item.
 

Thread Starter

HasRen

Joined Nov 21, 2019
4
Thanks Marley. Much apprecited. I think the problem with the Goodies.zip was with the PC I was using. I have just done it now with a different PC. I am sorted.
 

bassbindevil

Joined Jan 23, 2014
52
I'm just going to point out that the audio quality of this amplifier may not be satisfactory for music. It's probably fine for amplifying an alarm siren or making voice announcements, but without any negative feedback to linearize the circuits, I'd expect a lot of distortion. Note the lack of any measured performance specifications like distortion, noise, and frequency response. If a designer didn't measure those, how did he know it was working correctly, or that the circuits were optimized? But at least it doesn't run directly from line voltage like a similar project that was actually published in a magazine, so it won't try to kill you.
 

dendad

Joined Feb 20, 2016
3,176
Are you just looking for an amp, or do you want to make one?
If you just need an amp, I'd go with an Ebay ready built one.
https://www.ebay.com.au/itm/TPA3116D2-Class-D-Dual-Channel-Digital-Stereo-Amplifier-Board-2x120W-XH-M543/312793837363?hash=item48d3f72f33:g:aZUAAOSwnGldmaGp
ClassD_TPA3116D2.png

A couple of these were added into an old graphic equalizer as it was mostly an empty case. A suitable toroidal transformer and power supply fitted nicely so my son now has a 4 speaker PA for when they play their band outside. It works quite well and is cheap enough.
 

Thread Starter

HasRen

Joined Nov 21, 2019
4
Are you just looking for an amp, or do you want to make one?
If you just need an amp, I'd go with an Ebay ready built one.
https://www.ebay.com.au/itm/TPA3116D2-Class-D-Dual-Channel-Digital-Stereo-Amplifier-Board-2x120W-XH-M543/312793837363?hash=item48d3f72f33:g:aZUAAOSwnGldmaGp
View attachment 194245

A couple of these were added into an old graphic equalizer as it was mostly an empty case. A suitable toroidal transformer and power supply fitted nicely so my son now has a 4 speaker PA for when they play their band outside. It works quite well and is cheap enough.
Thanks dendad. It is a long term project wherein I am looking to actually build one for myself. I have built class A and AB based amps. So I want to explore with class D.
 

dl324

Joined Mar 30, 2015
9,332
Thanks dendad. It is a long term project wherein I am looking to actually build one for myself. I have built class A and AB based amps. So I want to explore with class D.
This article might interest you. Automakers are switching to Class-D for efficiency.

The article is undated, but I received a newsletter with the link within the past week.
 

Attachments

Audioguru again

Joined Oct 21, 2019
541
That class-D amplifier project is the only one that I have seen that has no audio spec's (the amount of distortion at certain output powers, and frequency response). Maybe it sounds awful because it has no negative feedback.
Its heatsink seems to be large so it is not as efficient that class-D amplifier ICs are.
 
Top