Description
This kit is a doorbell circuit that can make a “ding, dong” sound.
It is composed of a time base circuit integrated block and peripheral components.
It has beautiful and realistic sound quality, simple and easy installation, low cost, and low power consumption.
The core IC is the time base circuit integrated block 555, which constitutes an unstable multivibrator.
Press the button AN (installed on the door), the oscillator oscillates at a frequency of approximately 700Hz, and the speaker emits a “ding” sound.
At the same time, the power supply charges C1 through diode D1.
When the button is released, C1 discharges through resistor R1 to maintain oscillation. But due to the disconnection of AN, the resistor R2 is connected in series to the circuit, causing a change in the oscillation frequency, which is about 500Hz, and the speaker emits a “thump” sound.
Until the voltage on C1 drops to a level that cannot maintain 555 oscillations.
The length of the remaining sound of the “dong” sound can be changed by changing the value of C1
Working voltage:DC3V-9V
Packing List:
As Per Image
