Melody Doorbell circuit

Posted on Oct 26, 2012

In all the houses exist the bells in the door. All want, they have the possibility of being possible to change the intensity, the tone of sound. With this circuit we have this possibility. With the materials round the gates, we can change the sound. For the materials that exist in the circuit the frequencies are roughly 5 KHZ and 2 KHZ. The circuit functions only for small time interval afterwards the pressure of switch. Simultaneously with the sound we have also optical clue from LED D2. Changing the capacitors C2-C3, with different price of capacity, we create new sounds.

Melody Doorbell circuit
Click here to download the full size of the above Circuit.

Part List R1=470Kohm C1=22uF 25V Q1-3= BC 550 R2=22Kohm C2=470uF 25V Q2= BC 560 R3=3.9Kohm C3=1 uF 25V BATT=4X1,5V or external pack 6Vdc R4-5=330 ohm D1=1N4001 SP= Speaker 8R /0,5W R6=2.2Kohm D2=LED RED 3mm R7=1.2Kohm IC1=7413 All Resistors is 1/4W 5%

Leave Comment

characters left:

New Circuits



Popular Circuits

Servo controller with 555
Basic Oscillator (Tone Generator) At 1.8 KHz -alarm circuits
RFI-Free Ringer Generator Works Off Single 5-V Supply
Power Monitor
RF Remote Control With HT12E IC
Spy Phone Bug Transmitter Circuit
High Frequency VCO Design
Lights Out circuit
Scalable MAX610 output current power supply circuit b
Emitter negative feedback differential amplifier gain control circuit