Differential line driver encoder / Duty Cycle ?

I have a Differential line driver encoder (Dynapar HS20....)running at 12VDC ...

Am I correct to assume as frequency of the encoder output (say CH. A)varies with the RPM of the driven shaft, the measured duty cycle should always be 50% as measured on my Fluke 87 DMM ? (not counting imperfections in the encoder disk etc.)which would vary the reading by some small percentage...

I'm pretty sure that it will remain at 50% since that's how the lines are set up in the encoder.

I'm so sure that I would say that 100% of the time it will be a 50% duty cycle. But, then, I could be wrong ...

Changes in speed will generate momentary variances from 50%, else how would the frequency change? At least one of the half cycles must be a different length than its predecessor to arrive at a new frequency.

Bernie, True that would happen during the change in frequency, but at a stable speed the output from the encoder channel is going to be on 50% of the time right ?

Yes, constant speed should yield 50% duty cycle given the encoder imperfections you already pointed out.

danatomega said:

I'm so sure that I would say that 100% of the time it will be a 50% duty cycle. But, then, I could be wrong ...

Click to expand...

Probably should have qualified that statement with 'at a given frequency' ...