Found in a 1964 Electrronic Design, this circuit is intended to control analog video signals. The circuit has an attenuation of 45 dB at 20 kHz.
Found in Popular Electronics this circuit will trigger a buzzer if the ignition key is removed...
This circuit is from an English publication from 1973, but can be easily assembled today. 2N718 can...
The figure shows how to connect a relay to obtain the latch effect. The circuit is from an...