servo tester - simple and inexpensive, but effective

A problem frequently encountered in model construction is that of testing the functioning of a servo. The servo-tester described in this article provides the solution. It supplies an output frequency of 50 Hz; the pulse width can be adjusted between 1 ms and 2 ms and serves as an excellent test signal. servo-tester servo-tester elektor march 1983 simple and inexpensive, but effective G. Luber Figure 1. The servo-tester produces a PWM (pulse width modulation) output with positive output pulses whose width can be varied from 1 to 2 ms. The necessary circuit modifi- cations for negative output One possible cause of failure in radio-con- trolled models is a malfunctioning servo. The problem is: how can this be checked when the model is being operated in the field? Certainly during contests, when you are for- bidden to use the transmitter for testing. What we need is a battery-operated test circuit which supplies a PWM (pulse-width modulation) signal. The signal transmitted to the serv...