Alternative PWM to 0-10V converter for spindle control

[hurzhurz]

In case it is helpful for anyone, I want to hint to another PWM to analog converter that I found a while ago.

It is sold pretty cheaply on Aliexpress as a small PCB module called “PW1VA01”:
https://aliexpress.com/item/1005004402191795.html

It is based on an IC specialized for this task: Guestgood GP8101
Chinese Datasheet (try Google Translate for documents): https://datasheet.lcsc.com/lcsc/2202131930_Guestgood-GP8101-F50-NH-SW_C2837701.pdf

From what I found from my testing, it has strong advantages over the other typical modules:

• the output is absolutely linear and also frequency and supply voltage independent
• doesn’t need fiddling with an adjustment potentiometer
• it can achieve the full 10V on the output, even if the supply is a bit below 12V (so it works fine with the 12V-ish output of my VFD)

Slight downside: The module from above doesn’t have an optocoupler on it, so one needs to add one separately.

For myself, I actually hacked together a PCB in EasyEDA with an optocoupler and also some additional I/O channels:
https://oshwlab.com/hcsts/cncopto_copy
(please excuse poor design and use at your own risk … I’m not very experienced in circuit and PCB design)