High speed AC PWM frequency variator/dimmer

Other Hardware General Electronics
1

Hello Community,

I'm trying to find out the best path for getting a high-speed PWM AC driver.

I've seen 2 designs, one with 2 MOSFET's:

and one with only 1 MOSFET:

The idea is to use only a few parts and keep it very simple.

The circuit will act as a PWM driver for AC vibration solenoids, which demands high-speed switching, so SSR or any other part that has zero-crossing on/off is out of the question as we need to kick out about 2kHz, or maybe even more, for adjusting pumping pressure/speed.

These pumps are 230AC powered, and current consumption is between 27 and 52W.

I have checked this Fairchild MOSFET FCP190N60E, for high power switching as it is cheap enough. But I don't know if it is suitable.

https://www.fairchildsemi.com/datasheets/FC/FCP190N60E.pdf

Someone also told me about the possibility to use this type of random phase phototriac:

https://www.fairchildsemi.com/datasheets/FO/FOD420.pdf

The end result should be something like this: ( actually it should be much better :slight_smile: )

Can someone let me know if these are the best parts for the job? Can it be wired with one optocoupler to keep it safe?

As a guideline, this is how these type of pumps work:

Cheers!

2

which demands high-speed switching, so SSR or any other part that has zero-crossing on/off is out of the question

But, not all SSR's are synchronized to TURN ON with the next AC Voltage Zero Cross.

Can it be wired with one optocoupler to keep it safe?

Yes, optocouplers can help make AC High Voltage circuits safer.

Controlling the speed of a pump can be tricky because you need to manage torque, too.