Re: [CAD_CAM_EDM_DRO] Testing encoders on the "bench"

mueller914 wrote:

>Hello all,
>
>I was given a bunch of Pittman motors (DC brush) that have built-in
>encoders(500CPR)
>
>The problem is some of them "might" have bad encoders, so how could I
>test them on my work bench? Is there a simple circut I can build and
>plug into the motor harness to check that the encoder is working
>correctly?
>
>something like, LEDs that'll turn on and off or speed up or slow down
>when the motor is activated and speed up or slowed down?
>
>

The simplest possible circuit would be 2 LEDs, with 1000 Ohm resistors
in series, wired from the +5 V terminal to the A and B outputs of the
encoder.
You would connect the + side of the LEDs to the +5 V, the - side to the
resistors, and the other side of the resistors to the encoder outputs.

You will have to move the encoders in VERY minute movements to see the
LEDs blink on and off. You could also move them a bit and stop, and make
sure that each LED is on some of the time, and off some of the time.
You could also turn the shafts slowly, and make sure the LEDs are
half-bright
all the way around. If either LED goes out or to full-brightness, that
would
indicate dirt or damage to the encoder wheel.

Jon