We have a little strobe device that flashes an LED using a 555. That part is workign fine.
But, I need to add a little photo switch that will stop the 555 (or the whole unit) from working in the dark since it then is a safety hazard (flashing gets people disoriented). I thought this would be pretty simply - just interrupt the source to the 555 - either pin 4 or 8. But then all the circuits I've seen seem to have op amps, etc., and maybe this is more complicated than i am thinking.
My thought was to have the +9V source thru a resistor to the photodiode (other photodiode leg to gnd), and simply tap off between the diode & resistor to pin 4.
Not good enuf?
But, I need to add a little photo switch that will stop the 555 (or the whole unit) from working in the dark since it then is a safety hazard (flashing gets people disoriented). I thought this would be pretty simply - just interrupt the source to the 555 - either pin 4 or 8. But then all the circuits I've seen seem to have op amps, etc., and maybe this is more complicated than i am thinking.
My thought was to have the +9V source thru a resistor to the photodiode (other photodiode leg to gnd), and simply tap off between the diode & resistor to pin 4.
Not good enuf?