DC Motor pulsing

Other Hardware Motors, Mechanics, Power and CNC
1

I have a 12v DC Motor connected to a 18.5v 3A Laptop power supply. When I connected the setup the motor is working but it is pulsing(Working with regular intervals of idleness). The problem is getting the motor to rotate continuously without pulses. If I shorted the connection for some time, It will work perfectly after that with no flaws. I've also tried a 40V Printer power supply(I don't know the Amps). I tried connecting 4400μF capacitor(Rated for 50V) in parallel to the Motor but It didn't show any change at all!

What am I doing wrong here? Any resources for further reference is very helpful.
Thank You :slight_smile:

2

Have you tried running the 12V motor with 12V?

3

What setup?

Maybe because the 12V motor is cutting off at some portion of being driven by +18V?

4

More that likely the power supplies are being overloaded because you are just guessing at the current your motor is drawing.

Paul

5

More that likely the power supplies are being overloaded

+1

The motor startup/stall current is typically 5-10 times the no load, free running current.

6

Most power supplies cut out on overload, whereas for a motor you want current-limiting behaviour
on overload, since the initial stall current is likely to cause overload-cutoff-recovery-overload-cutoff....
beaviour.

Either you need a supply that current-limits (without foldback) or use a supply with enough current for
the stall current of the motor.

The amount of capacitance needed to tide a motor over during stall current conditions is prohibitively
large (and would cause the supply to cutoff itself anyway)