This circuit was obtained from an 80's EDN. The components used are still common. The circuit can be used as a shield and the frequency is approximately 775 Hz.
We found this circuit in an old Mullard (Philips) documentation. The load must be according to the...
One touch on S1 and the circuit turns on. With a tap on S2 it turns off. This is the purpose of...
We found this circuit in the 1974 Ferranti transistor manual. The transistors are general purpose, and...