No hay artículos en el carro
No hay artículos en el carroTodd K. Moyer
Comentado en los Estados Unidos el 18 de agosto de 2023
I ordered this encoder to experiment with it. It turns out to be very well made, and looks to be heavy duty. The actual when pulling out the string is very smooth, with what feels like a constant force that acts to pull the string back in, if let go.The spec sheet I got with it says 0.1 mm/pulse; to test this, approximately, I pulled the string out about 100 mm and counted the pulses with my oscilloscope. You can see in the scope photo labeled "pulse count" that I got 944-945 pulses (for A and B), when I would expect 1000. My pull distance was only approximate, so this looks pretty good to me.For my test I pulled up the A and B outputs with a 2.7k resistor each, to a supply voltage of 12 V (the spec sheet says 8-24 V for the supply).The A and B outputs are in quadrature, or 90 degrees out of phase, and you can tell whether you're pulling the string out, or letting it go back in, by looking at both outputs. If you take A as the clock, and latch the state of B on the rising edge, B will always be high on the rising edge of A, if you're pulling out. The opposite is true if you let the string retract.I'm knocking off a star because the datasheet gives no information out needing to pull up the A and B outputs, and you don't know how much current they can sink.Also of concern, but this is rather common with open-collector encoder outputs, is glitching from crosstalk between A and B. See the photos showing both negative and positive glitching in both the A and B outputs, exceeding 1 V. This indicates that you might want to reduce the value of the pull-up resistors, at the expense of burning more power to use the encoder. It's interesting that glitches on A from a falling edge on B are larger than glitches on B from a rising edge on A. I think this is because, due to the passive pull-up, the rising edges are slower, and less likely to couple into the oppositive output (via capacitive coupling).Summing up, this thing is not cheap, but if you need to measure linear displacement down to 0.1 mm, I think it's quite a good product. It would be easy to interface this to a microcontroller.
Jeff Carter
Comentado en los Estados Unidos el 16 de diciembre de 2022
Great value for the investment. 👍
Gene
Comentado en los Estados Unidos el 20 de abril de 2021
I thought the draw wire would give an absolute measurement. Was not the case.
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