Homemade grinding machine for precise work

**liberal** · Dec 17, 2019, 03:45 AM

There is a better scheme https://www.drive2.ru/b/469279260389933445

**Claudio HG** · Dec 17, 2019, 06:36 AM

That circuit is a beauty, too bad the TDA1085 is no longer in production and nearly impossible to find.
I also found things like this one:
https://www.banggood.com/220V-AC-Spe...r_warehouse=CN
but a friend of mine tested one of these regulators and noticed that have a really poor gain so the motor drops speed when under load by approx. 10%. Also it doesn't work if an encoder signal is provided instead of a tacho generator.