|
South Georgia | I'm not an electrical engineer, but as I understand Lance's suggestion, when the switch is first turned on, the current flows through the coil of the relay to one side of the discharged capacitor. Until the capacitor has sufficiently charged, the coil of the relay sees +12V on one side and 0V on the other. This engages the relay. As the capacitor charges, the coil of the relay sees the same voltage on both sides, which disengages the relay. There's my momentary on. When I switch my master switch 'off,' instead of just being an open circuit I've got a circuit that's closed to 0V instead of 12V now. This allows the coil of the relay to see 0V on one side of the coil and +12V on the other, from the charged capacitor. This engages the relay until the capacitor discharges to 0V, at which point the voltage differential is again zero and it releases the relay. The 12V and 0V are on opposite terminals of the relay than the previous cycle.
I still can't make it work in my head with the capacitor 'upstream' of the coil as in Lance's drawing, but it makes sense to me with the capacitor on the other side of the coil.
The capacitor won't discharge on its own, because the whole time my master switch is flipped on, one side of the capacitor will continue to see +12V. It will never see just an open circuit.
Thanks,
Adrian | |
|
Field IQ remote engage question? Momentary relay?
