Right, i'm after something that will do the following. Should really be able to do this myself but can't think straight at the mo. I've got an input, doesn't matter what it is, it's either high or low. Basically when it changes state I need to connect a pair of inputs together, so will probably involve some sort of relay for safety. But they only need to be connected momentarily every time the input changes state, for something like a second, not too long. Code: Trigger Outputs to be connected together |------- ----------| whatever :D | |------- Any help appreciated, can't be too complex.
How much current can the trigger provide/sink, and what kind of voltage is it? you can try a small transformer trigger to the primary , and make a diode bridge from low loss shottky (sp?) diodes, on the secondary, and run that to a darlington to get the pulses. It would really hep with the transformer if you could have an opposite signal (ie baldanced) to hook the other lead of the primary coil. But it is late and my brain is probably feeling as toast as yours. Hmm, if it (the trigger)swings from 12v to ground you could put a cap between the trigger and the 5v, and put two low-mid gain transistors biased oppositely in it, I'll fire up eagle and think about it.
Did it last night The caps keep current from constantly running, just flowing when it chages. The PNP transistors go low when the current flow through them. (you should probably put some resistors between the base of the transistor and capacitor and the emitter of the other.) The resistors are pull up resistors, and when either of the outputs go low, the nand gate goes high. connected to the solid state relay, it connects the wires momentarily. I'm sure someone else (acrim, zap or cpemma especally) could probably improve on that.
