Auto Headlight Off Timer
Victor Lopez
anyone help me with a simple headlight timer switch that would turn the
lights off after the car has been off for a while?
Thank you,
Victor
Please remove the 1 to respond...
John Woodgate
<vic...@swconnect.net> writes
>I am driving a 76 MGB & am constantly leaving my headlights on. Can
>anyone help me with a simple headlight timer switch that would turn the
>lights off after the car has been off for a while?
>
moment. That's why newer cars use a buzzer that sounds if you open the
driver's door with the lights still on. This is done with a double-pole
door switch, which you are unlikely to be able to fit. So a somewhat
more electronic solution is called for.
You need a pnp transistor which will easily pass your buzzer current.
Reverse diode 1N4002 across the buzzer (unless it's a piezo buzzer with
inbuilt oscillator). Emitter of the transistor to the headlamp supply.
Collector to + terminal of buzzer. Other end of buzzer to earth. Base of
transistor via 1 kohm resistor (might need to be less, but don't go too
low!) and a 1N4148 diode to hot terminal of courtesy-light switch on
driver's door. The diode cathode goes to the switch.
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John Woodgate <j...@jmwa.demon.co.uk> wrote:
>In article <3666B112...@swconnect.net>, Victor Lopez
><vic...@swconnect.net> writes
>>I am driving a 76 MGB & am constantly leaving my headlights on. Can
>>anyone help me with a simple headlight timer switch that would turn the
>>lights off after the car has been off for a while?
>>
>Not a good idea, as it may fail with the lights out at a critical
>moment. That's why newer cars use a buzzer that sounds if you open the
>driver's door with the lights still on. This is done with a double-pole
>door switch, which you are unlikely to be able to fit. So a somewhat
>more electronic solution is called for.
>
>You need a pnp transistor which will easily pass your buzzer current.
>Reverse diode 1N4002 across the buzzer (unless it's a piezo buzzer with
>inbuilt oscillator). Emitter of the transistor to the headlamp supply.
>Collector to + terminal of buzzer. Other end of buzzer to earth. Base of
>transistor via 1 kohm resistor (might need to be less, but don't go too
>low!) and a 1N4148 diode to hot terminal of courtesy-light switch on
>driver's door. The diode cathode goes to the switch.
John:
There's an easier way if the wiring of the MGB is hospitable. Assume a
car whose door switch grounds the courtesy lights and access to parking
light power. 1965 Ford's switched hot on the door switch.
Even a little reed relay works, because I am using this to derive alarm
system inputs. Again get power from the parking lights for the buzzer,
ground from the switched relay contacts. It's simpler and smaller than
another pin switch. Again use diode isolation for the driver's door.
If you wire a piezo buzzer between parking lights and the door switch.
It will come on with both doors.
Diode isolation at the door swich can isolate the driver's door. Use a
200 V piv diode at 3A for the courtesy lamp and a 1n400x series, 200 PIV
for the buzzer.
Have done it for about 15 years on a Toyota which already used one diode.
I just added another and a buzzer. Make the buzzer easy to replace,
because experience dictates that it needs to be replaced every 5 years or
so.
Ron
David Moodie
were a couple of circuits printed in Electronics Design fairly recently
on this topic. Check out the car circuits stuff from Bob Pease's
columns.
http://www.penton.com/ed/Pages/sitepage/extras/columns.htm
The circuit given sets off a buzzer if the lights are on and the
ignition is off, but it would be fairly easy to modify to include the
door microswitches.
regards
David Moodie
Victor Lopez wrote:
>
> I am driving a 76 MGB & am constantly leaving my headlights on. Can
> anyone help me with a simple headlight timer switch that would turn the
> lights off after the car has been off for a while?
>
John Chapple
>
> In article <3666B112...@swconnect.net>, Victor Lopez
> <vic...@swconnect.net> writes
> >anyone help me with a simple headlight timer switch that would turn the
> >lights off after the car has been off for a while?
> >
[snip]
Why not? IIRC daytime running lights have been mandatory in Canada for
about 10 years or so, and the manufacturers use a relay with the coil
connected between the ignition switch and ground. The lights go out
when the engine is shut down.
The best (IMO) designs turn the headlights (low-beams at 100%),
taillights, markers, etc. on all the time, so there is no worry about
leaving the lights on. It's done for you with the ignition switch. If
there are difficulties with bulbs burning out, the alternator is
overcharging the battery, provided good quality bulbs are used.
Regards
John
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Kevin
the door was opened and the light switch was on. I used the courtesy
light switch on the door.
A buzzer sounds when you try to get out with the lights on.
Kevin.
On Thu, 03 Dec 1998 09:41:06 -0600, Victor Lopez
<vic...@swconnect.net> wrote:
>I am driving a 76 MGB & am constantly leaving my headlights on. Can
>anyone help me with a simple headlight timer switch that would turn the
>lights off after the car has been off for a while?
>
XKMFDMx
use a DPDT relay with the coil connected to the battery via the ignition key
switch. When the ignition is on, the relay will be in one position, but when
the ignition is turned off, the coil is no longer energized, and the relay
switches to the other pole, completing a circuit powering a timer circuit that
is a "delay to break". I have one lying around from a machine control, and you
could probably find one that runs on 12VDC without too much trouble.
The lights are wired through the timer (at the fuse panel?), and once the time
delay elapses....lights out!
The control I have is made by Syrelec, and adjustable over a wide range of
times, so the time before the lights turn off would be very easy to vary...
Just my $0.02...
*Maniac* 1-978-440-8146 x.212=VMB
"There's nothing RIGHT about the Christian Right, and there's nothing FUN about
Fundamentalists."
My #1 frustration is that I can learn stuff faster than I can read it off the
page. It's a damn bottleneck.
Steven V. Christensen
was just that - a buzzer with no electronics.
Aparently you connect one side to your headlamp power, and the other to
your radio power (or some other key switched circuit). When the key was
off, that switched circuit was about ground. The buzzer would go off!
Simplicity.
Steven
TheCentralSc...@pobox.com
With the current of the buzzer going through the radio's power supply
possibly frying the radio with oodles of nasty inductive spikes...
I did something very simple: I put the headlights on a relay off the
ignition. I had gotten tired of having a dead battery every time it
rained and I had forgotten to kill the headlights.