7 batteries when he can measure the output voltage on the treadmill. If he has no output for the motor, chances are very good the motor is not the issue. You sure do like to complicate things don't you?You need 7 ea. 12v car/motorcycle/lantern batteries in series for a full voltage test. 4 ea. might be enough to start the motor, or keep it running after you spin up the shaft.
What tests do you want to run? Speed, torque, power?
If you want to vary the speed and still have low speed torque you need a controller like the treadmills have.
"How do I test a 90VDC treadmill motor?"7 batteries
like to complicate things
Can't you see
And keep your foot on the motor when you apply power, because if it works, the body will tend to rotate instead of the shaft. Also, if you have an automotive battery charger it would be easier to use in this case than the car battery.Take the motor out to the car and hook it up with a pair of jumper cables, rather than bringing the battery inside.
As stated by micromind, be very careful not to short the battery.
Hook jumpers to the motor before attaching the other ends to the battery.
Never heard of PWM in the same sentence as DC motor control, only AC motor control.Hi;
Some motor controllers will not output a voltage without a load, or may show full voltage even if the controller is blown.
To properly test, the motor should be properly connected to its controller, then tested with a DC voltmeter or an oscilloscope.
When the motor is running at less than full speed, the motor should receive a pulse-width modulated signal that will reach full voltage, but for shorter than the full cycle period. This is how DC motors are controlled to have high torque at low speeds.
If I had to put money on it, I would put it on the controller. The electronics are much more likely to fail than the motor is.
If it's a very old TM, then the motor brushes could be worn out, or worse, the commutator burned up. It could also be a motor bearing, but that's easy to test; Just try to spin the shaft (with the belt disengaged). If it spins, it's not the bearings.
Be careful if applying power to the motor while it is dis-mounted from the TM.
First, the motor runs on 90VDC, which can shock you nearly as badly as the 115VAC line can!
Another consideration is that; if the motor starts, it will jerk, and roll away, taking with it all the wiring and other equipment that is connected to it.
Best thing is to just disengage the belt and test with it still mounted to the frame.
If you are familiar with electricity, I can recommend another way to test the motor, but I won't disclose this unless you, the OP is confident you can handle it.
I'm reading the article, and checking other sources, and from what I can see, PWM works for both DC and AC motors.