This sensitive three-transistor circuit was found in Electronics Now magazine and is earphone-readable. The tuned range depends on the coil.
Suggested by a 90s Electronic Design, this circuit drains only 0.25 mA from its source. Listening...
The crystal frequency of this circuit found in an American documentation is limited only by the...
This current sensor employs the Texas Instruments LMV358A low voltage operational amplifier. This...