It is a significant advantage that most modern vehicles are equipped with built-in alarm systems. However, the sound of the horn when the alarm is armed can be perceived as noise pollution. Disconnecting the alarm system from the horn relay will eliminate this sound but will also prevent the horn from functioning during an actual alarm event. This circuit is designed to silence the arming beep while maintaining the alarm functionality by introducing a small delay into the signal. It is positioned between the alarm and the horn relay. The alarm must provide a continuous horn signal for a minimum of three seconds before the horn relay is activated. This ensures that the brief "beep" does not trigger the horn relay, while a sustained alarm signal will.
This circuit operates by utilizing a delay mechanism to differentiate between short and long horn signals from the alarm system. The primary components of this circuit include a timer IC, such as the 555 timer, configured in monostable mode, a relay to control the horn, and a few passive components such as resistors and capacitors.
When the alarm is armed, the timer IC receives the initial signal from the alarm system. If this signal is a brief "beep," the timer will not activate the relay, as the duration is insufficient to meet the three-second threshold. Conversely, if the alarm system sends a continuous signal, the timer will engage, allowing the relay to close and activate the horn.
The circuit can be designed with adjustable timing to accommodate different alarm systems. The timing period can be set by selecting appropriate resistor and capacitor values connected to the timer IC. Additionally, the relay should be rated to handle the current drawn by the vehicle's horn to prevent any damage.
This solution effectively addresses the issue of noise pollution while ensuring that the vehicle's alarm system remains fully operational in the event of a security breach. The implementation of this circuit is straightforward, making it accessible for automotive enthusiasts and professionals alike.It`s a great convenience that most modern cars come with a built in alarm, however it is nothing but noise pollution that the horn sounds when the alarm is armed. Disconnecting the alarm system from the horn relay will eliminate this, but prevent the horn from sounding in the even of an actual alarm.
This circuit serves to silence the arming beep yet maintain the alarm by introducing a small delay into the signal. It sits between the alarm and horn relay. The alarm must provide a constant horn signal for at least 3 seconds before the horn relay is activated. That way the quick "beep" will never activate the horn relay, while the constant alarm signal will. 🔗 External reference
The signal from COR triggers U1, which produces a beep-gate pulse that enables the analog gate. This gate consists of D2 and D3 to pass the beep tone generated by U2.
The circuit operates by utilizing a signal from the...
The LM39X4 functions as a LED-driving voltmeter, with its maximum and minimum readings determined by the resistor values R2 and RV2. When properly calibrated, the device operates within a 2-volt to 3-volt range but is designed to read supply...
Car and Motorcycle Battery Tester Circuit. Going camping today often requires bringing various electronic devices for daily activities or entertainment. Typically, a charged lead-acid battery and a power source are essential.
The Car and Motorcycle Battery Tester Circuit is designed...
While the power is on, the relay remains open; however, when the power fails, the contacts of the buzzer circuit close.
The described circuit involves a relay and a buzzer, functioning in a power-dependent manner. In normal operation, when power...
The phone alarm device is designed to monitor and prevent unauthorized use of a telephone line. When interference signals are detected on the line due to theft attempts, the alarm activates, preventing the thief from making calls while alerting...
This circuit provides an alert when a door that should remain closed is left open. It is designed to be attached to a fire door, allowing normal passage. If the door remains open for more than 30 seconds, a...
We use cookies to enhance your experience, analyze traffic, and serve personalized ads.
By clicking "Accept", you agree to our use of cookies.
Learn more