Voltage difference in PWMs

[Generalx5]

What is the potential difference in the PWM's we have? I dont have an Osciliscope, And the Multimeter is really hard to get it right, Anyone know?

[MrForbes]

I think the answer to your question is 5 volts DC, but I'm not sure if I understand your question correctly....

[ace123]

If you are talking about the Victors, you a really good way to test is the nice two-color LED on it that tells you just about everything you want to know.

The Victor light is the most accurate source if you are stuck with a PWM value problem... that one light tells you a lot of info. If it is flashing orange, it's a 3-pin PWM cable problem, or it's set to a special value that disables it (like if your robot is detached). If it's completely off once you run the code, the motors are running slowly or half-speed. If it's solid orange, they are inside the deadband or completely stopped. If it's bright red or green, it's running full power in forward or reverse.
Flashing orange could also mean a problem with the Generate_Pwm() or PWM() function calls if you are on ports 13-16... best to try switching to a different port if you aren't sure.

So the victor won't as accurately tell you the voltage, but you can estimate: if it's bright green or red, it's around +/- 10-12v. If it's off, it's not zero, and if the light is solid or flashing orange, there is no potential difference.

On the other hand, if you are just talking about the cables, sometimes it helps to ziptie them down right next to the base of the victors so that they can't get pulled out.

[bear24rw]

I don't really know what your asking either but.. the actual pwm outputs on the RC are unregulated.. so they will run at what ever voltage the backup battery is at. If your talking about the Victors, the voltage increases proportionaly to the signal it gets.. it can be any where from -12v to +12v

[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.