Vermes
Advanced Member level 4
Presented device is a perfect solution for everyone who always forget to turn off the lights in such places as garage and basement. This automatic after several minutes turns off the light, if somebody does not do that before. This construction is better than a standard staircase switch because such a switchcan not be disabled yourself, adequate time must pass so the light turns off itself. Time of staircase switches is also too short (approximately 5-7 minutes), because sometimes you need to be in the garage for longer. Presented here automatic turns off the lighting after approximately 15 minutes after turning on (it can be set using a potentiometer in range of 30 seconds – 15 minutes), if someone does not turn it off before.
Schematic:
You can use another counter instead of UCY 7490 and use it as a switch. Bell circuit breakers (one for each output) should be connected in parallel. It can be extremely useful when you plan to spend in a garage more than set 15 minutes and you can turn off the device (time circuit breaker on the schematic, blue button in the picture).
Link to original thread - Automat dla zapominalskich