This is an off shelf component that might fit my need. Unfortunately the documentation is terrible. It should convert a 0-5v or 0-10v analog to PWM (0-5v/0-10v is a jumper). The analog voltage signal controls the duty cycle. The potentiometer controls "Precision" per the description. I think they mean it can offset the duty cycle from the control signal. I don't care about that, I can program the control signal. This should be perfect for me if the PWM frequency is 21-28KHz.
I can't find/get any info about the frequency. It was cheap enough that I picked one up and started mapping out the traces. I've been trying to learn for a few hours now and I can't quite figure it all out. I think the 555 is controlling the frequency, but this doesn't look like any examples I have found. I want to know specifically which resistors/capacitor are controlling frequency and what it calculates to. I have the ability to rework the board and change them if needed. I don't have an oscilloscope right now, but I'm working on borrowing one. I'm hoping to figure this out and get any possibly needed components before I borrow the scope.
The picture should show connections, sorry if it is ugly. I will gladly clarify anything if confusing. FYI, I just used purple when it would cross over another red line.