This circuit for UHF between 800 and 1 000 MHz was found in an American documentation from the 90's. The integrated circuit is from that time, uncommon today.
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...