How to Build a Siren

This article will guide you on building an electronic siren. This siren can be a toy, or a fully-automatic outdoor warning siren.

A quick Google search turns up quite a few siren schematics, and even kits for the novice electronics experimenter.

1. Obtain materials from an electronic parts dealer.
2. Read schematic(s) carefully to avoid slip-ups and mistakes.
3. Place IC sockets and solder these into the jumper wires to other parts. Position thesocket so that the notch on the body is pointed up, or left. The notch denoted the end with pin 1. the pin-out of an IC is left pin, is one. Down the left side, then across the bottom to the pin, then up that side to make the final pin, the top pin on the right.
4. Place larger components such as capacitors. The leads for some components are long enough to do point-to-point wiring between components.
5. Place resistors. A common method of placement, is to put the gold (tolerance) band pointing in the direction of the signal/power direction.
6. Place any remaining components. Be sure to solder each part as you place it. Plug in any ICs now.
7. Double check your finished circuit to the schematic. Correct any mistakes while the power is off.
8. Power it up on 5-12 volts DC and connect pin 3 of the 555 timer to an amplifier. Connect the signal cable's screen to the circuit ground.
9. If you hear a tone, you have successfully built your siren.

• For an outdoor siren, you'll want to build a one-shot timer set at 3 minutes. This will allow the user to simply hit a button, and after 3 minutes, the siren will auto shut off.
• For any other siren application, a simple on/off switch will suffice.

• If you have built an outdoor siren, don't sound it unless it's test day in your area, or there is an actual emergency.
• If this is being used in a car, don't sound it while in motion. The authorities don't like a siren on a non-official vehicle. Using a siren while in motion is typically a serious offence.

• Schematics for your siren, and possibly a timer circuit.
• Amplifier and speaker
• battery or ac-dc adapter
• parts to build siren and timer.
• Perfboard to place parts into, and perhaps a breadboard to prototype on first.
• Solder (60-40 lead/tin) and a soldering iron.
• An outdoor rated enclosure if it's to be outdoors. If a siren is used a as a toy, a simple plastic enclosure is good enough.