Introduction :  
Very simple realization.  
This editing will allow you to know if a circuit is conductive or not,  
it will serve you in the realization of your circuit boards  
to ensure that the tracks are not interrupted, or cut.

the power supply is delivered by a simple battery of 9volts,  
- The BUZZER is a Piezo model with oscillator, model with studs to solder on printed circuit.  
- The LED will be red in color and 5 mm in diameter, the resistance will be 470 Homs.  
- It will also 2 sockets 4mm in diameter (isolated), with the 2 cords that go with it.

Attention when installing the LED, the flat side  
(cathode = negative side) is to be connected to the resistance (drawn in blue rectangle).