headlight reminder

Home / the12volt's Install Bay / Car Security and Convenience / headlight reminder (

Topic Closed)

Welcome Guest :)

Members

Search

Register

Login

< Prev Topic Next Topic >

limp

Member - Posts: 2

Joined: November 02, 2005

Location: Australia

Posted: November 02, 2005 at 6:52 AM / IP Logged

hi,

just like to ask if anyone knows how to use 2 BJT transistor to set up a car headlight reminder...basically a buzzer will sound when the lights are left on but the ignition switch is off..i've tried it with a 555 timer and would like to know how it is done with the transistors.

Back to Top

brcidd

Copper - Posts: 274

Joined: January 07, 2005

Location: Ohio, United States

Posted: November 02, 2005 at 7:00 AM / IP Logged

I've been going to radio shack and buying a $3.00 piezo chirp-- then simply wire at the fuse box- one leg to the instrument panel light fuse (usually 5 amp) and the other to the wiper fuse (or any ignition hot fuse) and be done- if lights are left on-with key off- the wiper circuit provides a good enough ground to sound the chirper- if both are on (ignition and lights) then no sound, if both are off, then no sound. Has worked on every older car I have tried- and sure beats replacing a chime module for $60. If you turn off the instument lights at the dimmer switch- the chirping quits- as the OEM systems were designed.....just my thoughts.....

Brcidd - Engineer That Does Remote Starter Installs on the side.

Back to Top

KPierson

Platinum - Posts: 3,527

This member consistently provides reliable information

Joined: April 14, 2005

Location: Ohio, United States

Posted: November 02, 2005 at 7:57 AM / IP Logged

You could possibly use an NPN transistor on the headlight feed, and send its (-) output to the (-) side of the buzzer.

Then, you could use a PNP tranisistor on the ignition circuit, as long as it rests at ground. This could output a 12vdc signal to the (+) side of the buzzer.

You could also use one NPN and wire the base to the 12vdc headlight source, and the emitter to an ignition source that rests at ground. When the headlights are on, and the ignition is off you will get a (-) output from the collector.

Kevin Pierson

Back to Top

limp

Member - Posts: 2

Joined: November 02, 2005

Location: Australia

Posted: November 02, 2005 at 8:41 AM / IP Logged

thanks guys..yeah i found it on the website already for the transistor but still not sure how to calculate power rating, current n voltage. anyone knows any website for 555 timer mini projects...wanna check some connections to the Ic itself.

Back to Top

Sorry, you can NOT post a reply.
This topic is closed.

Printable version

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

Search the12volt.com

Follow the12volt.com

Disclaimer: *All information on this site ( the12volt.com ) is provided "as is" without any warranty of any kind, either expressed or implied, including but not limited to fitness for a particular use. Any user assumes the entire risk as to the accuracy and use of this information. Please verify all wire colors and diagrams before applying any information.

headlight reminder

Sorry, you can NOT post a reply.This topic is closed.

Sorry, you can NOT post a reply.
This topic is closed.