links for 2007-10-30

if we are only interested in knowing when and for how long our signal of interest is above some threshold, we could use transistors to produce a circuit with an output voltage that is high or “on” when its input signal is above a “turn on” threshold a

Sometimes an input signal to a digital circuit doesn’t directly fit the description of a digital signal. For various reasons it may have slow rise and/or fall times, or may have acquired some noise that could be sensed by further circuitry. It may even be

This is basically a Schmitt Trigger circuit which receives input from a cadmium sulfide photo cell and controls a relay that can be used to switch off and on a street lamp at dawn and dusk. I have built the circuit with a 120 ohm/12 volt relay and monitor