Electrical parts keep breaking!

[nighterfighter]

Originally Posted by dharg99

Also I recommend tinning wires to newbs, helps them understand the wires a lot more.

I would recommend you don't tin your PWM cables...

[Mr V]

Originally Posted by dharg99

PWM cable system only need the white and black for proper communication... I believe the old motor controllers needed the red for extra power as their ability to send the pwm message was weaker than the new talons and victors


Also one thing I've learned being head electrical on my team is simply don't try if you don't know...

Electrical isn't like programming where you can hit backspace, in electrical things can burn, arc weld, explode, and kill you.

Also I recommend tinning wires to newbs, helps them understand the wires a lot more.

None of the FRC legal motor controls of the recent past have used the 5v signal wire in the PWM cable.

The way the motor controllers that I have looked at their schematics work is that the black and white wires are connected to an optoisolator. So all the signal does is light up an LED.

[Ether]

Originally Posted by dharg99

I believe the old motor controllers needed the red for extra power as their ability to send the pwm message was weaker than the new talons and victors.

If by "old motor controllers" you mean the Jaguar, Vic884, Vic888, VicSP, Talon, and TalonSR... then no, the red wire is not used.

[Ether]

Originally Posted by Mr V

None of the FRC legal motor controls of the recent past have used the 5v signal wire in the PWM cable.

The white wire is the signal wire, and the black wire is ground. Both are needed.

The red wire is power (not signal). It is needed only when the PWM cable is connected to a low-power servo motor. It is not needed for any of the motor controllers.

The way the motor controllers that I have looked at their schematics work is that the black and white wires are connected to an optoisolator. So all the signal does is light up an LED.

The signal (white) wire carries the PWM command on it.

[dharg99]

Originally Posted by Ether

If by "old motor controllers" you mean the Jaguar, Vic884, Vic888, VicSP, Talon, and TalonSR... then no, the red wire is not used.

Yes, those motor controllers, however victor SP should not be on that list as the don't use the red wire, it's only there as the stock pwm they get in manufacturing is used for all their products, they just cut the red on the Vic Sp's

[Ether]

Originally Posted by dharg99

victor SP should not be on that list as the don't use the red wire

non sequitur. None of the motor controllers in that list use the red wire.

perhaps you meant it shouldn't be in the list because it's a new motor controller, not an "old" one.

[Mr V]

Originally Posted by Ether

The white wire is the signal wire, and the black wire is ground. Both are needed.

The red wire is power (not signal). It is needed only when the PWM cable is connected to a low-power servo motor. It is not needed for any of the motor controllers.



The signal (white) wire carries the PWM command on it.

Yes I worded that very poorly. The red wire is connect to a 5V supply at the Roborio but is not connected to the circuitry of the motor controller.

The white wire supplies the actual signal to the motor controller.

[Al Skierkiewicz]

Originally Posted by nighterfighter

I would recommend you don't tin your PWM cables...

Matt,
Can you be more specific? Under what conditions?

[nighterfighter]

Originally Posted by Al Skierkiewicz

Matt,
Can you be more specific? Under what conditions?

Sorry, I should have said the connectors, specifically the male end (the 3 pins).

The pins are already a semi-tight fit into the female ports, and tinning them shouldn't be needed to make them stay in. Hot glue around the connector would work better for that, if needed.

If the pins are being tinned because the signal is acting wonky, the wire itself could be broken at a certain point causing intermittent connections, or the crimping at the connector could be bad.

[Al Skierkiewicz]

I agree that male pins should never be tinned. I also do not recommend hot glue. It rarely works like you want because the parts are too big to get hot enough and the glue will get down inside some devices and lift surface mounts parts off the board.

[philso]

Originally Posted by Al Skierkiewicz

the glue will get down inside some devices and lift surface mounts parts off the board.

How does that happen?

[Al Skierkiewicz]

I believe it has something to do with rapid expansion and contraction during the application. We won't use hot glue.