[sci.electronics] Headlight buzzer

commgrp@silver.ucs.indiana.edu (BACS Data Communications Group) (10/11/90)

John DeArmond and Steve Tell write:

>>Making a (lights-on alarm) is trivial.  All one needs is a Sonalert 
>>or similiar device and a 1 amp diode (1n4002 works well).

>[text replacd with picture]

>                      Diode                   Buzzer
>Headlights ------------->|----------------------()--------- ACCessory
>                                               +  -

This version has an override switch so you can stop the buzzer in 
case you really want the lights on with ignition off:

             diode      o----- Hdlts.
          -----|<-----/ o----- Ign.
       +  |
 buzzer  (*)       dpdt sw
       -  |             o----- Ign.
          ------------/ o----- Hdlts.

If you forget to reset the override, it reminds you by buzzing next 
time you turn the ignition on with the lights off.  A similar circuit 
was in _Popular Electronics_ c. 1958.

--

Frank Reid     reid@ucs.indiana.edu