I have an older 8L? single speed Biax Half Moon metal scraper which has a 240V 220w AC brush motor.
The scraper as standard only had one speed making it awkward to use, I fitted this dimmer switch as an in line speed controller and now have a reasonably variable speed unit.
Seems to work great and at a fraction of the cost of a variAC.
How long is it likely to last I wonder and are there better alternatives?
Paul