This interesting circuit uses a sodion valve that we have already described in an article on the website. The circuit uses several batteries for power. The phone is of high impedance.
This 45 to 90 Hz hum elimination circuit was obtained from a 1980s documentation. The operational can...
This circuit is suggested by the Optoelectronics Sourcebook by Texas Instruments when AC signals...
This amplifier for a sinusoidal function generator uses a 741 integrated circuit. The circuit is...