OK, here is part 2 – or part of it anyway. I am still currently constructing the amplifier, but I will upload the video on Tech Ingredients very soon. I will continue to edit this post with more details as the project progresses.
So let me start out by showing you the schematic (right click and view to see the full size image):
You can see that I am using four MOSFETs and four drivers here. In my actual build, I decided to use four drivers and eight MOSFETs. It doesn’t matter however because the fudnamentals are just cloned to the extra devices. Another discrepancy is that I am using two turns on the primary of the balun and one turn on the secondary. The balun core consists of four FB-61-1020 glued together with silicone. I also purchased four FB-43-1020. I’ve gotten mixed answers in my research regarding which one will work better so I got both to try. In addition, I also got some c2m0280120d MOSFETs in addition to the ones shown in the schematic because they were recommended, but I think the ones I chose in the schematic should be better (they have much higher current and lower RDS on).
Here is the PCB:
Just to note, all of this and more can be found in the archive download I listed in the part 1 post.
So what we need to make this working is:
1. Audio amplifier – https://www.parts-express.com/wondom-aa-ab31242-1x600w-class-d-audio-amplifier-board-(t-amp-technology)–320-3346
2. Heatsink – https://www.heatsinkusa.com/8-000-wide-extruded-aluminum-heatsink/
3. A fan – I am using a 12V crossflow fan that can be found on Amazon or eBay.
4. 1:1 toroidal transformer (1000VA is what I am using, but it’s probably overkill) – http://www.antekinc.com/transformers/
5. PCB (I have a few in stock, but have gerber files too)
6. Electronic components – there is a list in the archive described in part 1.
7. The ferrite cores (described above) – http://www.amidoncorp.com/fb-61-1020/
http://www.amidoncorp.com/fb-43-1020/
http://www.amidoncorp.com/t157-3/
8. MOSFETs (included in parts file)
9. Low pass filter – got it from rf2017 on eBay.
10. RF DDS generator + LCD control board – from rf2017 on eBay.
http://www.ebay.com/usr/rf2017
Send rf2017 a message. He was the one who helped me out with this design. He has his own designs also. His are all pre-built, so if you are looking for something similar to this already made, then check him out. None of his designs are as high power as this (as of now). He also has a Youtube channel you should check out here. I based my design off his amps, so he deserves some credit.
Another site that was helpful during this build was: http://www.maxmcarter.com/classexmtr/circuitdescription.php It is a class E transmitter instead, but there is a lot of info there that is helpful anyway.
Alright, I’ll continue to update this as my build progresses. . .