Found in a Popular Electronics from the 80's, this circuit makes use of a time integrated to control a relay in a timed way. R2 determines the activation time.
The 74123 TTL integrated circuit consists of a monostable that can be configured to generate...
This VCO or Voltage Controlled Oscillator was found in a Popular Electronics from 1991 but can be...
In the figure we have the power supply for the 8 W amplifier in the previous circuit. The circuit...