Project on LED Bargraph Optical Tachometer

For the electric R/C enthusiast, a tachometer can be a very useful piece of equipment. When I first built this tach back in 1995, it was essential, as there were very few off-the-shelf electric R/C power systems that just worked. At that time, you had to experiment with batteries, speed controls or switches, connectors, and wiring, and a tachometer was a tool to help you measure the results.

Now in 2006, a tachometer is still just as useful. By performing RPM measurements from time to time, problems such as a bad cell in the battery, deteriorating connectors, or damaged motor windings can be detected early before there's a major failure.

There are of course many commercially available tachometers for R/C these days, but if you're like me, it's more fun to build your own. 

 For Details Download here:

Optical Tachometer.pdf