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I've got a m1000 automated tape dispenser and I've just recently found this sensor at the cutting blades.

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As far as I know the wire from the cutting blades to the main board was only for automatically printing tape endlessly when switch is switched. And I doubt that the sensor's used for measuring the length of the tape. Because even though when the tape is empty it will continue cutting the air. Measurement of the tape is done by a hall sensor measuring the rpm of a motor. And so does the cutting blade itself. It's also measured with a hall sensor to check the blade position.

And how do I use this sensor?

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The sensor sounds like a tape out detector. It may not be working correctly based upon the type of tape being fed through the machine. – Michael Karas Jun 16 '14 at 15:28
Might have even been assembled wrong, as I don't see polarity markers on the thing passing for a harness. – Scott Seidman Jun 16 '14 at 20:50
up vote 8 down vote accepted

Looks like a reflective optical sensor to me, but I have no way of knowing. The arrangement looks like an LED/photoreceptor pair. The LED may well be IR. I suspect this would be for sensing empty tape, even though it's not functioning. It may not be supported by the current firmware version, or it may be enabled in a cadillac version of the dispenser.

You might hang out in the dark for a bit with the unit on. IR LED's often bleed into the visible, especially when your eyes are dark adapted. You may see the orange glow after a bit.

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You can also detect the IR with a cheap cell phone or digital camera. – Ricardo Jun 16 '14 at 12:46
It appeared to be an empty tape detection sensor indeed. I thought this as well at the first place but since it didn't stop when the tape was empty I had no clue what it would be. But I've noticed that it stops cutting rarely when there is no tape in the machine. So it isn't working properly. – Handoko Jun 17 '14 at 7:44

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