I have a situation where I am taking off an ignition coil to read RPMs. And to kill two birds if i ground out the primary it kills the ignition. Its a strange set up i know but this is how it is.
R3 was choosen as this allows at least some current to allow the circuit to work, and hence get a reading on the arduino. the circuit works a charm and thanks to the boys at Arduino.cc. at the same time providing enough resistance so that the ignition finds its way to the spark plug, rather than grounding. Or to put it better to allow the engine to start as you can tell there is more resistance as its harder to start.
so its at the point where there is just about enough current for the circuit to work and just about enough resistance to allow it to start.
the cap was placed in as a presumptive measure to combat noise before R3 and has stayed ever since, all i can say is that it works and if i remove it -it doesn't.
What could i improve to ease the burden on the primary whilst still allowing current into the circuit.
Thanks
R3 was choosen as this allows at least some current to allow the circuit to work, and hence get a reading on the arduino. the circuit works a charm and thanks to the boys at Arduino.cc. at the same time providing enough resistance so that the ignition finds its way to the spark plug, rather than grounding. Or to put it better to allow the engine to start as you can tell there is more resistance as its harder to start.
so its at the point where there is just about enough current for the circuit to work and just about enough resistance to allow it to start.
the cap was placed in as a presumptive measure to combat noise before R3 and has stayed ever since, all i can say is that it works and if i remove it -it doesn't.
What could i improve to ease the burden on the primary whilst still allowing current into the circuit.
Thanks