I want to try and make the output power of the following driver board adjustable. At full power it runs at 100watt I. The board itself does not have an option to reduce the power output. The output voltage is 220v (I think), output frequency is 40khz (most likely pwm square wave).
Here is the driver circuit board I'd like to use: https://www.aliexpress.com/item/33001673042.html?spm=a2g0o.productlist.0.0.3d644912VCTYPe&algo_pvid=1c2f1089-3691-4e06-88a1-95689226a60f&algo_expid=1c2f1089-3691-4e06-88a1-95689226a60f-36&btsid=07fe0fa2-3398-48aa-a224-770f018b1ea3&ws_ab_test=searchweb0_0,searchweb201602_5,searchweb201603_52 Image:
I don't think it can be done by placing another pwm signal generator (/"dimmer) on either the input or output side. I'm quite sure it would mess up the output frequency of the driver board. Perhaps I could use a lot of triacs in series to get the desired voltage drop and in this way reduce the power but this is probably a bad way of doing it. Variable resistor is not an option I think due to the high power draw (approx 100w).
PS: I'd be using this driver/the high frequency transducer to try and build an ultrasonic cleaner.
Any suggestions on how to solve this problem will be greatly appreciated. Thank you very much!