"Headlights, Automatic Off".

Created: "June 18 2011"
Latest Update: "June 24, 2011"

A Simple circuit to Turn Off your Headlights in a pre-determined time, After you turn off your motor.

I Designed this for one person who keeps forgetting his lights are on.
Just to get a Dead Battery later.

Electrical Connections.

1) I Recommend you Remove (or Splice Into) the Hot Input Wire going to your Headlight Switch.
This should not only turn off your Headlights, but also your Park Lights,
Further Protecting against a Dead Battery.

The P-Mosfet and IC Supply voltages get wired to this HOT SIDE of the Headlight Switch.
This is so Source of the P-Mosfet and the IC are Always getting 12 volts from the battery.
And the Drain of the P-Mosfet now connects to the Headlight Switch.

2) The 220 Resistor needs to connect to a circuit "on/or after" the Ignition Switch
that Turns OFF the Power when the Key is Turned OFF.


Now if you leave your HeadLights On, they will Automatically Turn OFF,
after a PRE-DETERMINED Time. (See this Info on the Schematic.)

And Next Time you start your car, The Headlights Will come on Again.
So if you aways like your Lights on, Just leave your headlight Switch On.

NOTES: If you want less than a 1 Second delay for going OFF, Use a
10uF Cap (with the 100K) instead of the 100uF.
Do NOT Eliminate this Capacitor alltogether, as it also helps prevent
Spikes from going into the CD4011.

This circuit should work on Most Vehicles,
But it is impossible for me to test it for all Situations.
So you must build it and use it at your own Risk.

Not much else I can say now, maybe more later.

An Etched and drilled PCB's and a kit of parts is available.

 The Schematic

 "Circuit Board."

 "Picture Overlay and Bench Test".

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