Found in a Popular Electronics from the 90's, this circuit is used to recognize the frequency of a modulated infrared signal. The LM567 circuit must not be supplied with voltages above 9 V.
This oscillator was found in a 1967 EEE. The transistor supports a modern equivalent. The power...
This second-order low-pass Salen-Key filter was obtained from an American 1980s documentation. Formulas...
This interesting circuit of a 1988 documentation consists of a mouse trap where the sensor is left to...