[writchie]

RC servos are normally powered by nicad packs, nominally 7.2 Volts. Most don't work very well at 5V (unless they are 4.8V versions) which is why the sidecar powers them with a fixed 6V supply (the low point for a 6 cell pack).

The PWM signal is a 5Volt pulse. The pulse is nominally between 1.0 and 2.0 ms with 1.5ms representing the center position. The 1.0 and 2.0 ms pulse widths correspond to clockwise and counterclockwise travel limits.

The pulses are usually repeated at 30 - 100 hz. The off time is not critical as long as it is shorter than about 30ms.

If you intend to control your own servos or PWM devices you will get better results with an active buffer to drive the servo cable high and low through a series resistance . Look at the schematics for the sidecar to see how its done well.