This circuit detects smoke by changing the light falling on the sensor. The circuit was found in the Electronics Experimenter's Handbook of 1991. Optical devices must be used.
Found in documentation from the 1970s, this circuit uses an oscillator and a display to warn of...
This circuit simulates a low-level siren and can be supplied with voltages from 5 to 15 V....
The filter shown in the figure, using only an operational amplifier, is characterized by allowing 1...