On Reminder - By Gert
many times have you forgotten to switch of your head lights? And
you only remember it when it is to late and the battery is flat
or when you have locked the doors and is on your way .
Well this is
a DIY project that almost any one can do for under R.20.00
All you need
is a diode 1N4007 and a 12 Volt buzzer. And some wire.
Start by connecting the buzzer and diode in series as show in the
picture. If the buzzer and diode is connected to a battery it will
buzz. But if you turn the polarity around on the battery then nothing
should happen. This is because the diode is blocking the flow of current.
If you take
the Positive lead of your park lights and connect it to the diode
permanently and just for testing purposes connect the buzzers negative
lead to the ground (negative of the battery) and you switch on your
lights the buzzer should buzz.
that is not what we want. We want the buzzer to buzz only if the
lights are on and the ignition is off.
the buzzers negative lead from the ground (negative of the battery)
and connect it to the ignition switch. Test with the tester to make
sure you get the right wire that only has power when the ignition
is switched on. Or alternatively connect it to the wire that feeds
the car radio. Providing that the car radio only work when the ignition
is switched on.
if you switch the lights on while the ignition is off the buzzer
should sound. And as soon as you switch the ignition on the buzzer
this will help you from forgetting your lights on in the future.
the discussion on this topic here
Uys van Rooyen posted this diagram as another option: