slipping clutch monitor

I have clutch on a machine which I want to monitor for slippage. There two toothed wheels and two proximity switches, 1 set on the motor side and one on the load side (the exact number of teeth I am not sure about at the moment) now I need to monitor the difference in frequency of pulses from these somehow and I was wondering if there was a panel mountable unit that would do the job. I.E. monitor the frequency of the two signals and give an output at a preset difference. Any ideas?

What kind of speed is involved. If the on and off times of the prox switches are less than the PLC's program scan time, you'll need high speed inputs.

pauly said:

I have clutch on a machine which I want to monitor for slippage. There two toothed wheels and two proximity switches, 1 set on the motor side and one on the load side (the exact number of teeth I am not sure about at the moment) now I need to monitor the difference in frequency of pulses from these somehow and I was wondering if there was a panel mountable unit that would do the job. I.E. monitor the frequency of the two signals and give an output at a preset difference. Any ideas?

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Red Lion makes a panel mount dual input rate meter, Gemini 52.

This will do.

• Dual Rate w/Ratio (A/B)
• Difference (A-B)
• Draw [(A-B)/B]
• 69 mm x 133 mm
• 6 Digit, 0.56" (14 mm) LED
• Displays A, B, or C Channel
• Dual Assignable Relay Outputs
• Serial Communications
• NEMA 4/IP65
• Up to 10 KHz

http://www.redlion.net/Products/Groups/Counter/Rate/GEMINI52/Docs/03009.pdf

Assuming that a PLC CAN see the inputs as seperate pulses and if the toothed wheels have the same number of teeth then start two counters.

Over a desired time period allow the counters to count. If, during the time period, the motor side counter accumulator gets greater than the load side counter accumulator by a certain amount then there is too much slippage. You decide the time period (after which you re-zero the counters and keep going) and how much difference in counts is acceptable.

Or there's even the dual rate PAX, which we'd suggest over the Gemini for newer apps.

http://www.redlion.net/Products/DigitalandAnalog/Counters/CounterRate/PAXDR.html