IRS 2092 Class D Amp Kit - Oscillation or Normal?

[nickb]

I used a different numbering. The 100K and 20uf are a low pass filter to remove audio so only allow near DC to appear on Q1 and Q2. If the voltage there is > 0.7V Q1 will turn on, if < -0.7V Q2 will be on. Thus if the DC voltage on the output exceeds +/- 0.7V the collector of Q1/Q2 will go low. That will turn off Q3/4 and the relay will open so protecting the speaker. I'm ignoring D32 in your diagram.

[TomCarlos]

Dang... you guys are good!! I was looking on the wrong side of the relay, not to mention my continuity tests were with the power off !!

Nick, great diagram!! I don't know what software you used, but nice job!!

Next step, checking to see if a U.S. Starbucks card will work in Canada and the U.K. !!!!

[TomCarlos]

Here it is.... a final stab at the full schematic for the LJM L15D Version 2 Amplifier. I was able to scrunch in Nick's output protection diagram in the upper right. I crossed out resistor and cap values that were different from the base schematic. I added a few notes are well.

The eBay seller is now shipping a version 3 of this kit. There are few changes from version 2. So if you are thinking about building a stereo system, buy two boards.

Again, thanks to G1 and Nick B for contributing to the thread.

Update 4/10/2020: I forgot to mention that for Version 3, the two Mosfets have been replaced by a single IRFI4019H-117P, 5 pin Mosfet.

[nickb]

A while back you asked what schematic capture I used and I forgot to respond. It was ltspice. Whilst it's really a simulator you enter the data using a schematic. It's particularly fast and easy to use as a sketch type tool. What it is not a a real schematic capture package i.e doesn't have the hooks needed for manufacture.