Proa

RING BELL ELECTRONIC CIRCUIT USING NE555 DIAGRAM

This circuit produces oscillating frequency around 1kHz, and able to be converted by changing the value of resistor R1. The speaker will produce a long beep sound with 1kHz frequency. Here is the schematic :

Parts list :

•     Resistor R1 : 10k ohm
•     Resistor R2 : 56k ohm
•     Capacitor C1-C2 : 0.01 uF
•     Polar capacitor C3 : 1 uF/15V
•     IC timer : NE 555
•     Speaker : 8 ohm 0.5 W
•     ON/OFF switch
•     5-15V Power supply