A siren enhancer circuit is an electronic circuit, with which different types of siren generators such as UM66, UM3561, UM3481, etc. work in pairs. This circuit is ideal to use in a place where there is a need for a loud siren output. In this project, we are going to design a simple 10 Watt siren enhancer circuit using IRF9540 P-Channel Power MOSFET.
The IRF9540N is a P-Channel Power MOSFET. The MOSFET can switch loads that consume up to 23A continuous current and operate below 100V. It also has a decent on-state resistance of 0.117Ω which increases the efficiency of the MOSFET since it will dissipate less heat as a loss.
Hardware Components
You will need the following parts to build this project.
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Breadboard | – | 1 |
| 2. | Battery | 9v-12v | 1 |
| 3. | Connecting Wires | – | 1 |
| 4. | P-channel MOSFET | IRF9540 | 1 |
| 5. | NPN Transistor | 2N3904 | 1 |
| 6. | Speaker | 8 ohm | 1 |
| 7. | Resistor | 1.2K, 330 ohm | 1, 1 |
IRF9540 Pinout
2N3904 Pinout
Circuit Diagram
Working Explanation
The operation of this siren enhancer circuit can be broken down into 2 stages. In the first stage, the output from any siren generator ( UM66, UM3561, UM3481, etc.) goes to the base of the transistor 2N3904.The transistor preamps the signal to a certain degree before sending it to the 2nd stage for further amplification.
In the 2nd stage, the preamp signal from the first stage acts as the control signal at the gate terminal of the IRF9540 P-Channel Power MOSFET. The IRF9540 Power MOSFET further amplifies the signal & delivers it to an output audio device such as a loudspeaker or a PA system.
Applications
- Commonly used in home security setups & monitoring systems.
- Industrial uses such as fire & substance danger alarms.
- Civil defense uses such as alarms for early warning systems.
- Usage in Emergency services such as police & ambulance sirens.
- Usually found in devices such as screamers, PA Systems & loudspeakers.
