This circuit was found in an Electronic Design from the 90s. The circuit uses a type J thermocouple that can measure from -50 to + 100º C. Power is provided by a 3 V lithium battery.
Hartley oscillator operates in the audio range. Frequency can be adjusted by P1 and also depends...
This circuit was found in the June 1991 issue of Radio Electronics magazine. The circuit uses two...
This filter is intended for 60 Hz noise suppression in amplifiers. We found it in American...