I'm new to the forum and a total noob to electrical engineering.
I have a 120W, 24V DC gear motor. Runs at ~200 RPM no load connected straight to a 24V power supply.
However, when I connect it to a PWM controller, the RPMs max out at ~170. The PWM controller has an input range from 6V-90V DC, rated for 15A, PWM frequency of 15 kHz, duty cycle is supposed to be adjustable from 0-100%, uses a 10k potentiometer.
After doing a little research, I thought that maybe I needed IR compensation. But, it seems that IR compensation is more for keeping RPM stable with and without load. My drop is happening without load in both cases. So, is there a loss of power associated with using a PWM controller?
From what I've read, PWM should yield pretty close to full power. And, since my controller is adjustable from 0-100% duty cycle, 100% duty would be full power or the whole 24V right? Any insight as to why the motor is not performing at full potential would be greatly appreciated.
Update: Using a Fluke meter I took the following readings, as requested in this answer below:
With meter set to AC, measuring across the motor and varying the pot. The reading bounced around a lot when I moved the pot. With that said, once things settled down I got 0 at min, 0 at maximum and 2 at middle.
With meter set to DC. DC input = 24.5. Motor voltage = 21.2. +DC input to Motor+ = 0.6, -DC input to motor- = 2.7.