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:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    DC Servomotor Controller
    25 Watt MosFet Audio Amplifier
    DC motor PWM speed control
    Instrument preamp
    Clamp-on-current probe compensator
    Gas-smoke-detector
    TDA7000 FM Radio Receiver Circuit
    Digital Clock
    2ChPre
    metal detector circuit
    Radio Circuits
    Coilgun Knowledgebase
    PIC IR Decoders
    Automatic toilet flushing circuit
    Heart rate detection circuit diagrams



    Top