This is the receiver for the previous transmitter. The microphone is of the high impedance ultrasonic type. The circuit activates a relay. The operational amplifier supports equivalent.
Found in documentation from Analog Devices from the 90s, this amplifier uses a component from the...
This charger was found in an 80's Electronic Design. The circuit uses components from that time....
This double tone generator uses a specific integrated circuit, having been found in a 1977 CMOS...