This circuit was obtained from an American documentation from 1968. The current depends on the operational, observing that the circuit uses a symmetrical power supply.
This 10 kHz filter is based on a 741 operational amplifier. The circuit is from Electronics Now...
This circuit can be used with common drills connected to the 110 V network. With change of R1 and...
Found in an Electronics World of 1966 this circuit is intended for use with a microphone as an...