An ordinary automatic room power control circuit has only one light sensor. So when a person enters the room it gets one pulse and the lights come 'on.' When the person goes out it gets another pulse and the lights go 'off.' But what happens when two persons enter the room, one after the other? It gets two pulses and the lights remain in 'off' state. The circuit described here overcomes the above-mentioned problem. It keeps a tab on the number of people enters the room and number of people leaves the room. When ever the number persons remain in the room become zero power to the room is switched off. If somebody enters the room again the power is restored.
Also an Automatic Fan Speed controller changes fan speed as a function of the room temperature. This result in a more comfortable room condition as well as saving in electric bill. A temperature sensor and phase angle power control system is employed for fan speed control.
View attachment Abstract-Smart Room Power Controller.doc
Smart Room Power Controller
An ordinary automatic room power control circuit has only one light sensor. So when a person enters