This circuit is from a 90s documentation. It has a hysteresis and uses a light sensing bridge. The circuit generates a 1000 Hz modulated 10 Hz signal. The signal must be applied to an amplifier.
We found this simple preamp circuit with only one transistor in a documentation from the 70s. The...
This switching power supply is ideal for LCD multimeters that use 9 V batteries (which spend...
This circuit sends its signals through a wall acting as an FM spy. The circuit is from an...