We found this circuit in the Radio Electronics magazine of February 1993. The main integrated circuit is from that time and the power supply is made with voltages of 6 to 15 V.
If you have a common analog multimeter, you can increase its input resistance in the measurement of...
This circuit was found in a 1980s documentation. Q1 and Q2 can be BC548 and SCR a TIC106. The...
This circuit has a logarithmic response as a function of the light falling on the sensor. The...