auto alarm schematic | Next Electronics

ICla and IClb are configured as a slow astable multivibrator, while IClc and ICld are arranged as a fast astable multivibrator. The output from the slow astable modulates the frequency of the fast astable, and the output from the fast...

Ambulance sirens circuit

This circuit produces a siren-like sound similar to that of ambulance sirens. Unlike traditional ambulance siren circuits that typically use an IC 555, this design employs transistors, making it more economical and easier to customize. The operation of the circuit...

"Hee-Haw" Electronic Siren

The oscillator based on IC2 generates sound, with its output connected to the base of TR1, which amplifies the signal to drive the speaker. Resistor R4 limits the current through TR1 to a safe level. The oscillation frequency of IC2...

Wailing alarm

This circuit simulates the sound of an American police siren. IC2 is configured as a low-frequency astable multivibrator, producing a cycling period of approximately 6 seconds. The slowly varying ramp waveform generated on capacitor C1 is fed to the emitter...

electronically designed siren

The circuit was designed to create an electronic siren to produce an alert sound in emergency situations or any circumstances that require its usage. The 4011 is a quad 2-input NAND gate integrated circuit, characterized by minimal voltage supply fluctuations,...

IC 2 tones Siren

Double-tone Police sound Single-tone old ambulance sound This circuit is intended for children fun, and can be installed on bicycles, battery powered cars and motorcycles, but also on models and various games and toys. With SW1 positioned as shown in...

POLICE SIREN USES FLASHER

A low-drain circuit powered by a 1.5-V cell utilizes National LM3909 flasher integrated circuits (ICs) to replicate the "whooper" sounds characteristic of electronic sirens found in some city police cars and ambulances. Two flashers are necessary to create the required...

Police siren

This blog showcases project documentation of various projects completed by members of the Association of Experimental Electronics. Some projects are beginner-friendly, while others are intended for more advanced solderers. The core components of this sequencer were assembled during the Modular...

Electronic Locker Guard

Protect your locker or briefcase from theft using this pocket-sized gadget. It emits a loud police siren to attract attention. The circuit utilizes a single integrated circuit (IC). This circuit is designed to provide a compact and effective security solution for...