This circuit keeps the neon lamp on for a moment when it receives a pulse. The turn on time depends on C. The transistor is of the old type, from the 60's, when the circuit was published.
This powerful amplifier was part of commercial sound circuits from the 90s. The integrated circuit...
This circuit generates a control tone that serves to adjust amplifiers, check audio cables. The...
This circuit locks when the sensors are opened. The relay can be 6 or 12 V depending on the power...