This sensitive 5-band circuit was found in a September 1995 issue of Electronics Now magazine. The headphones, for greater sensitivity, should be high impedance.
This circuit is from an American technical documentation from the 70s, but it can be easily...
This circuit converts a range of input voltages at frequencies from 800 Hz to 3.7 kHz. This is a...
This circuit has a configuration that is widely known and explored on our website. The SCR can be...