I would like to built a circuit as the tittle says. The motor is going to be a windshield wipers car motor driving from a pc power supply at 12v. It going to be used as a homemade ball mill motor and is going to operate more than 4 days continiously. Any thoughts ?

 

You have to know the current at 12v when the motor is not loaded and when it is heavily loaded.
Here is the circuit to add:
One turn will be about 5 amps. You will have to calibrate the circuit or simply use the 10 amp range on a DMM.

 

Look for a PWM DC motor controller that can supply the current you need. Those winshield motors tipically use a lot of current.

 

Here is a PWM cct if you wish to build, spec in a suitable Mosfet for the motor driver.
They are also very cheap on Ebay.
Max.

 

I found this simple circuit that it is almost the same as Max posted

https://www.electronicshub.org/wp-c...Speed-Control-of-DC-Motor-Circuit-Diagram.jpg

By adding a suitable FET you can drive anything i believe. Baybe i will add one more transistor between FET and pin 7 from IC to drive the FET better. So what you think

 

I don't see why you would need an intermediate fet or bi-polar.
Max.

 

Is the current from the 555 out going to be enough to operate the FET ?

 

What RPM switching rate are you using?
Normally not a problem for motor control, the FET is voltage operated, unlike Bipolar which is a current operated device.
Essentially a transconductance device.
Max.

 

Ok max thanks for your replies, i will try the above circuit once i got some time.


Thanks