Can I remove DC motor driver's speed control potentiometer and drive it with microcontroller DAC output ?

[R1S8k]

Hi,

I was searching for 1-ph DC motor driver board that I can change the speed with a microcontroller.

The drive signal should be with DAC signal, because I'm using a PLC with relays as main output switches, but there are couple DAC output 0-10V. Which are DA0-DA1 on this pin layout:




The motor driver board is this one:



I think this driver board uses only a MOSFET with gate driver voltage using the potentiometer.

So my idea is to remove this potentiometer and instead connect the DAC lines from the PLC. Would that works ? theoretically I think it should work.

 

[danadak]

That is a PWM controller, so question is does the pot a part of
timing control on duty cycle or is it a V input to a PWM generator.

Can you get a schematic of board and/or part numbers of ICs
on board ?


Regards, Dana.

 

[R1S8k]

Yeah, you're right it's listed as a PWM board. But where is the part that produces the PWM signal ?

This is the board link on Aliexpress, there's no schematic.

Mini DC-DC 4.5V-35V 5A 90W PWM 12V DC Motor Speed Controller Module Adjustable Speed Regulator Control Governor Switch 24V Board

Can you help me finding a MOSFET board that is driven by DAC signal ?

 

[danadak]

Post a pic of topside of board where one can read the part numbers. Can you
find a schematic on web ?

You are looking for a "Voltage to PWM" if your posted board has no PWM on
it. And you have to match DAC range out to PWM range V input. Search
Aliexpress using that term, many hits.

This is how simple that problem can be with a trivial solution using Arduino :



Basically this generates Arduino code from blocks you setup (right hand window). Uses 8 pin
dip part. But we need to know more specs and config about your board.


Regards, Dana.

 

[Bluejets]

There will be a 555 timer underneath the electrolytic cap.
https://www.electroschematics.com/review-of-the-hw-687-dc-motor-control-module/

There are other similar mosfet modules (D4184) with opto's that will take a separate pwm signal as an input.
https://www.aliexpress.com/item/4000302453083.html

 

[crutschow]

You need a voltage to PWM board such as this, to drive a PWM to Motor driver, such as the D4184 posted by BJ.