Voltage difference in PWMs

[Al Skierkiewicz]

So there is no confusion in interpreting all the answers...
The PWM outputs of the RC are powered by the backup battery (7.2 volts) and the power pin is used on any servo connected to one of these outputs. The signal line of the PWM output is generated by the RC processor and is conditioned (opto coupler, noise filter, etc.) at the input of the Victor or servo as designed. The Victor does not use the 7.2 volt pin. The power for the Victor is derived from the main battery and the output is switched main battery voltage. The output of the Victor varies pulse width not voltage and in so doing varies the average current in a motor to control the speed. If you were to look at the output with a scope you would see a sqare wave of varying pulse width but the peak voltage would be the same as the main battery less the voltage drops due to wire losses and the series resistance of the FETs in the Victor. The output of the Victor changes polarity (M+ becomes negative and M- becomes positive) when the signal calls for the output to be reversed.

[bear24rw]

Originally Posted by Al Skierkiewicz

The output of the Victor varies pulse width not voltage and in so doing varies the average current in a motor to control the speed.

Ah, yeah I forget about that..

[Generalx5]

alright, the user reference tells you that its 7.2V just like the backup battery, thanks!

[Jared Russell]

The PWM cable has 3 wires.

Black is ground (0 V).
Red is power (7.2 V from the backup battery - NOT USED by the Victor)
White is signal (0-5 V TTL)

The Victor changes its speed 120 times per second based on the last PWM positive duty cycle read. If the duty cycle is 1.5 milliseconds, then you are in neutral. 2.0 ms is full forward. 1.0 ms is full reverse. In between are the intermediate speeds.