Categories: AlarmFun Circuits

Wailing Alarm Siren

Here is the wailing alarm siren circuit diagram:

Components List:

R1,R5___________ 4.7K
R2______________ 47K
R3______________ 10K
R4______________ 100K
Rx______________ *see text
C1,C4__________ 100uF/25V, electrolytic
C2,C3__________ 0.01uF (10nF), ceramic
T1_____________ 2N3702 (NTE159, TUP, etc.)
IC1,IC2________ LM/NE555, MC1455P, etc
LS_____________ Loudspeaker


This alarm circuit uses timer IC to generate frequency. The circuit has wide range supply voltage 5V to 15V DC.

*The Loudspeaker LS and the resistor marked “Rx” should be together 75 ohms. If you have a standard 8-ohm speaker then Rx is 67 ohms. The nearest value is 68 ohms. So for a 8 ohm loudspeaker Rx is 68 ohms. For a 4 ohm loudspeaker Rx is 71 ohms, for a 25 ohm loudspeaker Rx is 50 ohms, etc.

circuit diagram by Tony van Roon,
source: http://www.sentex.ca/~mec1995/circ/wailing.htm

circuit diagram

View Comments

Share
Published by
circuit diagram

Recent Posts

Guitar Synthesizer Schematic Diagram Collection

Guitar Synthesizer Schematic Diagram In this post, we provide a collection of schematic diagrams of…

54 years ago

Handy Talky HT DIY Schematic Diagram

Handy Talky Schematic Diagram This is an old electronic scheme of the Handy Talky (HT)…

54 years ago

Doorbell Ringer Birdie Tone

This is an old or "very old" schematic diagram of birdie tone or sound generator.…

54 years ago

200W MOSFET Amplifier based IRFP250N

Here is the 200W MOSFET amplifier powered based on four piece of IRFP250N, they are…

54 years ago

300W RMS Stereo Power Amplifier based IC TDA7294

This is the 300W RMS stereo power amplifier circuit project. This amplifier is based four…

54 years ago

Stereo Tone Control with Line In + Microphone Mixer

This is an active stereo tone control circuit using very well known op-amp IC of…

54 years ago