This circuit is from a publication from the 70s. The operational amplifier is from the period. Modern equivalents according to the motor current must be used.
The CMOS 4046 integrated circuit is not very common today, consisting of a very efficient PLL for...
This configuration with complementary transistors causes an LED to flash at a frequency that is...
This circuit was found in a 1968 documentation. It makes use of both NO and NC reed-switches and small...