This circuit was found in a Popular Electronics from the 90's. The CMOS integrated circuit used is not very common nowadays. The range depends on the infrared LEDs. R7 can be changed.
The idea of this circuit from a 1960 publication is simple: we can switch the transistor being...
This project makes use of a technology without many digital components and that can be easily...
When the light falling on the sensor is cut off, the SCR fires, powering the lamp. Remember that...