We are running a 6 CIM Drive for the first time this year. We want the security of running each speed controller to a separate PWM port on the DSC but we don’t have 6 to spare. Can we create a 3 way splitter cable to attach to each speed controller, and on the other end wire two PWM connectors in Parallel and attach it to 2 PWM ports? This photoshould help clarify. That way we save 2 PWM ports and we have some redundancy in the electronics.
Find it highly unlikely that only one port on your sidecar will fail and in a way that it would not interfere with the signal from a second. I also don’t know how well the controllers would like having two signals sent to it all the time, Im guessing that the signals would not be exactly the same. Also I think it to be more likely for your pwm y cable to fail more than any port on the DSC, and adding to the number of pwms connected to each other will increase the probability of a connection coming loose.
It’s feeding into an optoisolator in each Talon out of a 330 ohm resistor in the DSC. The PWM output can source or sink 15ma. Most optoisolators turn on around 1.6ma. We’ve driven three Talons before with no issue but Mike might have thoughts about whether it’s likely to be on the hairy edge.
Most likely so*. If there’s a schematic, I haven’t been able to find it.
out of a 330 ohm resistor in the DSC
Yes. There’s a schematic for this.
The PWM output can source or sink 15ma.
With a dead short, yes.
Most optoisolators turn on around 1.6ma
The spec is available for the Jag, and it is guaranteed to turn on with 1.6 ma.. Since there’s a 150ohm series resistance and a voltage drop across the LED, it requires about 1 volt to push that 1.6 ma through the LED.
So if you drive 3 Jaguars being driven by one DSC PWM port:
With this fix, you’re using 2 slots anyway, so why don’t you just use a y-cable and a normal PWM for each side? As mentioned above, I can’t see one port failing and not the other, although I’m sure its possible; just not likely enough really to worry about.
That is, If you don’t just want to run the three PWMs off one port, which probably would work just fine, as discussed above.
Does your team have access to an oscilloscope? If you want to be on the safe side, you can measure the voltage waveform (and magnitude) on the signal line in your PWM cable. It can give you some assurance that you’ve got adequate operating margin.
FWIW, I just found this note in the spec for the H11L1M optocoupler used in the Jaguar.
We’ve been running three Talons from one cable this season and haven’t noticed anything unusual. It would be good to know if we’re living on the edge, or are well within the normal operating capabilities.
The evidence is starting to mount that doing this should be OK, but yes you are wise to want to confirm that. I will trying sending a PM to Mike Copioli to alert him to this thread and see if he can help.