Bo Deadly
Well-known member
Just to be clear, so relay current is returned on the cable shield?
Just to be clear, so relay current is returned on the cable shield?
So supply for the relays is delivered by the control cable but returns to the power supply by a completely different "dcom" path. That's not ideal because sudden changes in current will emit an electromagnetic field that could invoke currents in nearby high impedance and / or high gain circuitry. For example you could get spurious digital events like you engage / disengage a relay and a bunch of LEDs flip erroneously. If return followed signal, the electromagnetic fields would cancel and that wouldn't happen. The caps on the transistor bases will probably slow things down enough that it will be ok but you might try to not run those lines next to digital lines if possible.boji said:They return to dcom via the relay daughter boards housed within each of the channel/group cards (no current on i/o pins).
Thanks again.So supply for the relays is delivered by the control cable but returns to the power supply by a completely different "dcom" path.
you might try to not run those lines next to digital lines if possible
Perhaps I should make a block diagram as I'm probably not using the correct descriptive terminology. Thanks for your time, still good food for thought.I'm not sure I understand the identifiers you're using to describe your circuit
I think this is where the confusion lies, as no positive voltage needs to get sent out of the M/C logic pcb to drive relays. Their 12v source comes from the channel pcb's. The logic pcb only serves to sink cv so to disengage relays, and both 12v and 5v sources eventually share dcom bus.the only conductor in that cable bundle that could supply the source current would have to be the cable shield.
True. They even have a provision to invert a side's pins all in one go.you could just change the code
/SaluteCarry on.
while (!Serial) delay(500); //wait 1/2 second for console voltages to stabilize
I would never use delay(). Your code is no different from just:boji said:Is there ever a valid use for delay()?
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