Re: Tachometer kit

I have been working on a variable speed controller for a machine tool
company that wants a LOW COST tach to read the spindle speeds as run by a DC
variable speed motor.
I would think that the guys that have added treadmill motors to their
machines would love one of these so that you know what your actual speed is.
I am working on one that uses a low cost LCD display that is 1.75X1. It
reads the pulses in counts per seconds and uses a refllective IR sensor that
reads 4 reflective strips attached to the spindle. Then a PIC (programmable
chip) send 15 pulses everytime the sensor detects a reflective strip and
thus converts the display counts to RPM's. I have had it running as fast
as 5400 RPMS and as slow as 90 RPMS. It compares very closely with an
optical tack and a mechanical tack that I have.
If there is enough interest. I could have some printed circuit boards made
and some PIC chips burn't in.
I would estimate that the kit would sell for $75-$85 complete with the
sensor, the LCD display the printed circuit board. An assembled unit would
run $85-$95. It operates off of 5 volts and a wall wart or a battery 4.5V
would suply power. It draws very little current so the batteries should last
years.