The Universal motor used in a washing machine has a taco which provides a signal via two wires to assist the computer control the washing machine operational speed. When reusing the universal motor for other projects is there an after market type of clock digital or otherwise that can use this signal to visually provide the operational rpm.

 

For an ANALOG RPM readout, an LM2917 tachometer IC can work quite well, BUT you will need to calibrate it knowing the frequency to RPM ratio of that signal. For an actual digital RPM counter scheme you will need a frequency counter with an adjustable time base.

 

about 35 years ago I used a device like that to indicate speed in a machine. To calibrate I had to enter the number of pulses per revolution during the calibration setup sequence . The device was made by the "ANALOGIC" company. It was a bargain, based on not needing to spend time designing and calibrating and building. If that company is unavailable, another company, "RED LION" also makes a similar device, and it is alive and doing well. Red LIon is an excellent company to work with.