Low-cost Car Battery Security Alert System

Abstract

This is a technical article that showcases a low-cost car battery security alert system that utilizes a multi-vibrator circuit into a dual-tone multi-frequency (DTMF) output (loud beep sound) alarm to monitor and safeguard the car battery from local theft. The entire circuitry is a simple one and low-cost in production. The incessant cases in which car batteries are stolen especially in developing countries is on the high side. And the cost of replacing car batteries is on the increase daily. Therefore, one needs to secure her car battery from street theft. Using both mechanical fastening and electronic security-based systems one could sleep with two eyes closed. The device serves as an electronic watchdog on the car battery in the car while it is parked outside the owner’s residence or elsewhere. The security system is provided with an internal rechargeable battery energizing the alarm circuitry, having a single-pole double-throw (SPDT) relay, and connected cables, with an output sound capable of alerting the neighbourhood. Whenever the car battery is disconnecting from the terminal heads or the loop cable is broken the connected alarm will be triggered and this will call the attention of the neighbourhood and the owner thereby deterring the intruder. The entire system was simulated using Circuit Wizard software with good results. The system was fabricated using discrete semiconductor devices that are relatively simple and available for operation and maintenance, packaged, and tested. The circuit voltage is 11.52 volts and draws a current of 3.79A resulting in a wattage of 44 watts. The device is affordable.

Keywords

• Alarm system
• battery thieves
• car battery
• multi-vibrator
• protection system circuits