This circuit with RTD sensor was found in the Radio Electronics magazine of April 1992. At the output we have 1 mV for each degree Celsius.
This old oscillator using germanium transistors has a high impedance headphone as inductor to...
This old fashioned amplifier can source some watts to a low impedance loudspeaker. The circuit...
This 50 Hz rejector or notch filter was found in a 1975 documentation. Other frequencies can be...