I'd like to convert a hall-effect flow meter to operate as on-off switch. the output is in pulses, which arrive at a rate proportional to the flow rate. what I would like to do is have a circuit that would turn on and off like a conventional flow switch. i.e., a circuit that you can tell: "if X pulse rate, turn switch on."
Thanks! edit: what I'm thinking about is basically a delay on make timer with the interval set to some timing that would give me the toggle function. e.g., we are getting 5 pulses per second, with the timer set to something just over 200ms, such that the on state is maintained as long as that many pulses continue to register.
but if it goes to 4 pulses, the frequency will be too low, and rejected by a Schmitt trigger or comparator.
There, I think I just told everyone how little I know. :)