homemade speed controlllers (for school project)

[Alan Anderson]

Originally Posted by Denman

Has anyone ever made their own speed controllers for the robots?
Note this is for a School Project.

[voice=codger]I was programming robots and wiring speed controllers before you young'uns were born.[/voice]

In 1981, I was the principal programmer for a group building a radio-controlled robot (featuring a TV camera and two-way audio) for an engineering open house event at the University of Illinois. The electronics guy designed and built a 16-step pwm speed controller, using a separate mechanical relay to switch between forward and reverse. We tested everything out using a single 12-volt car battery and it worked well, if a bit slow -- the motor and circuitry were intended for a 24 volt supply. When we were satisfied with the results, we added the second battery. It went fine until we gave it full throttle, at which point the speed control circuit caught fire.

One of the diodes neatly unsoldered itself from the board and broke the circuit before we could react. Replacing those diodes with heftier ones fixed the problem, and the Synton Amateur Radio Club Telepresence Robot worked fine thereafter.