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Never forget to turn off your headlight ever again!
Most new cars already have a headlight alarm built in but there are still many cars out there without that feature. This circuit is cheap and easy to put together.
For a few other car-related gadget ideas, why not have a quick look at Cruising: Gadget Masters for your car.
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Comments (4)
The headlamp warning cicruit is not interlocked to the courtesy light circuit. This means that it is impossible to leave the car with the lights on without the alarm sounding as might ocurr if one is waiting in the car with the lights on and engine off.
If the intention is to feed the alarm from the headlamp feed then a flat battery is still possible if the side lights are left on.
The functionality as shown could have been achieved by simply wiring the piezo buzzer in series with a diode between the lighting feed and ignition line.
Posted by Jeremy Stevens | October 10, 2007 1:21 PM
Posted on October 10, 2007 13:21
What a ridiculously over-engineered solution. A buzzer in series with a diode between the lighting feed and the courtesy light switch works well for me. Buzzer sounds when you open the door which is when you need the reminder.
Posted by David C Brown | January 22, 2008 5:25 PM
Posted on January 22, 2008 17:25
I'm missing something on the simple solution of a diode in series with buzzer between lighting feed and courtesy light switch. How do you get a voltage drop between the two? is one switching the 12 V and the other switching ground?
Posted by Ray Earley | December 16, 2009 9:32 PM
Posted on December 16, 2009 21:32
As regards the above comments, the vehicle I was planning to use this on is 24 years old and has no courtesy lights, so a circuit not relying on the courtesy light door switch (which would indeed have been the simple answer) is of no use, so this one sounds ideal. Unfortunately, at the time of writing, the circuit link is down so I can't use it anyway! (404 error)
Posted by Glen Graham | December 30, 2009 6:26 AM
Posted on December 30, 2009 06:26