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.
This circuit was obtained in a 90s 73 magazine for radio amateurs. The power transistor must have...
The circuit shown is an AM radio for the Japanese mid-wave range of the 1960s. The circuit has a...
This circuit brings together the drawing of the sports lottery, lotto and sena in a single digital...