Hobby diy
Metal Detector DIY schematic
The heart of this metal detector circuit is CS209A. The metal detector it is build with one coil of 100uH. CS209A has one oscillator wich forms an LC circuit, the inductance of the coil will change when it is near metal objects.
LED 1 will light and the buzzer turns on when the coil is changing [...]
Run dog, angry dog chaser
This electronic schematic will chase away angry dogs. It is build with the all known 555 circuit, a buzzer and a little ferrite transformator.
The frequency must be set with a dog near by .
