Still haven’t got speed control, I have been looking into all sorts of speed controls. Now I came across full bridge rectifiers, which are some what cheap. From my understanding it just changes ac to dc. But the dc that comes out gets a ripple effect, which I read and can be cleaned up with capacitor multiplayer circuit (widely used in higher end audio systems). Then I can pwm or dac the dc signal. I’ve read extensively that the universal motor will run the same on dc with same power input. So the idea is:
Rectify 120vac 15amp (whatever is coming out of my wall plug) to dc …ends up being 127vdc . After filtering and hardware loss should come closer to 120vdc still maintaining the 15 amps maybe some loss on amps… didn’t read anything on amp loss
From my understanding running a universal motor with no load on ac will just keep accelerating until max Input power , if resistance is not added on the input circuit. Which I opened mine Apart yesterday and saw it’s just a cable to a switch to the motor. I am assuming this is why the rating was 1200w , I am assuming they just multiplied 120v * 10amps to get the 1200w rating. The only thing that might give the motor any load or resistance control is the exhaust fan which is connected to the shaft.
Now, after rectifying the ac - dc you can invert it back to ac ( this is how vfd work) I have one of those car inverters it is rated 400w / 800w peak. Don’t know if that is the type of inverter That I can use since it’s meant to run off 12v and has alot of amps to work with. I read it’s some sort of IGBT inverter that you need, another project for another time.
Solid state relay. Basically from my understanding is opto controlled circuit that is controlled with a triac , so no mechanical latching all digital, the gate of the triac is working with its internals to do zero crossing etc, I had a random idea of by passing the zero cross detector on the relay with pwm or dac signal that is controlled by programed MCU with the rpm sensor. I don’t even know if that will be a viable alternative then having to pair / solder components for 120v 15amp circuit to get the full ac load which can produce much higher then The PIDs for sale that are 500w rated.
So any advice on converting ac to dc with rectifier to use dc style speed control, or do you think it is possible to bypass triac gate on SSR?