Three-tone electronic doorbell 1

Posted on Feb 5, 2014

The three-tone electronic doorbell circuit consists of buttons Sl-S3, transistors Vl, V2, speaker BL, resistors Rl-R3, capacitors Cl, C2, diode VD and battery GB, and it is shown in Figure 3-109. Rl-R3 use the 1/4W carbon film resistors or metal film resistors. Cl uses the electrolytic capacitor with voltage in 16V; C2 uses the monolithic capacito

Three-tone electronic doorbell 1
Click here to download the full size of the above Circuit.

rs or polyester capacitors. VD uses the 2AP9 germanium ordinary diode or 1N4148 silicon switching diode. Vl uses the 3DG6 or S9013 silicon NPN transistor; V2 uses the 3AX31 germanium PNP transistor.

Leave Comment

characters left:

New Circuits



Popular Circuits

300mW FM Transmitter
audio notch filter
Safety flare
Used for the surface acoustic wave of gas detection shaking circuit design
simple tiny door guard
NIXIE I NIXIE clock using six ZM1030 tubes
Advantages and challenges of third-overtone IC crystals
555 IC Square Wave Oscillator circuit
IC Adder Chip
Colpitts Oscillator Practical Project
Capacitive load drive circuit diagram of the MAX4106 4107
5G14D + 24V 1.9A power supply