[Snakub]

Here is my friends explanation of it-"cycle by cycle" current limit that does not require manual reset. It is reset each PWM cycle. The PWM clocks a flip flop. The output of the flip flop is ANDed with the PWM. The flip flop is cleared by the over current signal. So the PWM is started on the leading edge of the PWM. It is ended by the end of the PWM or the over current signal - whichever comes first. You need to make sure the flip flop clocks on the leading edge of the PWM signal and a few other such details. If you try to command more than the current limit this limits to the current limit and will run at the current limit rather than shutting off.

He showed me a schematic of it and it looked like an AND gate and a latch. The pwm signal and the latch both went to the AND gate and the circuit would operate as normal but whenever your lem current sensor goes to a certain voltage it triggers the reset of the latch to turn the circuit off for sometime.

I would just like to know has anyone tried this? What are the pros and cons?

 

[Snakub]

Maybe I am wrong but from what I understand the p and s motor controller board relies a lot on software whereas this would be strictly a hardware thing that uses just a pwm code with a micro or analog board. If I could build this with 3 or 4 parts why buy that board with 100 or so parts on it?

 

[Snakub]

I have just had a lot of bad luck with kits whether they be a lie detector, snooper ear, or a robot power motor controller and my soldering is above average. But usually when I solder something up myself on a perf board then I know its right and I only have one person to blame if its wrong and I know damn well what's wrong with if it doesn't work. My micro that I soldered already has opto isolation and an isolated power supply. What I mean by four parts is just for the over current protection but your right there may be a few more parts.