Hi.
I am trying to build a CMOS device that will sense rising and falling edges, and produce one of two clear digital 'blips'. I want it to differentiate rising and falling, to have its own power source, and to be able to sense voltages up to 250 ac, or at least 40vdc, but show a high impedance to the signal.
I have built more than a few purely digital circuits: timer and counting and logic based gadgets, but seem to get into trouble when I try to use comparator or op-amps.
Any suggestions would be helpful.
I asked this once before and got one response suggesting I try to find a 'test probe' circuit, but they seem to be aimed at ttl circuits, and the thread seems to have disappeared - or I cannot find it.