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.
Found in an English documentation from 1989, this circuit uses components common today. The...
The LED frequency flashes depends on the value of the capacitor tested according to the table. We...
Found in a Popular Electronics from the 90s, this circuit generates a signal that depends on the...