Maker Pro
Maker Pro

Notifier for diff locker off

Hi. Back when I was 12 - 15 years old I was interested in elecronics. Then my interests shifted towards software programming.

Right now I have a 4x4 with mechanical transmission, locker, and hi-low selector.

http://www.google.ru/search?um=1&hl...urce=og&sa=N&tab=wi&ei=-y9KT_rHKsjptQaClamUBQ

During offroading extremes, locker has a tendency to turn off. Not once I found myself in mud with locker off. Problem is usually I don't keep my attention on locker, and end up spending a lot of effort getting myself out of bad situations.

I need a circuit board which will notify me via sound and blinking led when locker is turned off. There is a 12V light bulb in the car, which is on when locker is engaged, and off when it is disengaged. It be nice to have a sound notification when this light bulb is turned off, plus a blinking led up in driver's face.

Can you help?
 

Harald Kapp

Moderator
Moderator
To get sound, you can simply connect a 12 V buzzer (e.g. here: http://www.buzzersdirect.com/) across the indicator lamp. Add a simple switch in series with the buzzer so it won't annoy you while the locker is intentionally off.

For the alarm light you could use a blinking LED (e.g. here http://ledz.com/?p=leds.blinking) with a suitable series resistor (approx. (12 V - 2.5 V)/20 mA) = 475 Ohm.
Put this circuit parallel to the buzzer.

Regards, Harald
 
Harald,

I think he needs it the other way round, i.e. the circuits should activate when the light is out.

I think a changeover relay with the coil connected across the bulb would do, using the back contact.

Duke
 
Yea, need the sound to come when the light is off. It be nice if the sound turns off automatically, beeps a couple times, and then off to sleep. Please draw a diagram. Thank you!
 

Harald Kapp

Moderator
Moderator
Duke, you'r right, I didn't get that in the first place.

A changeover relay or a normally closed relay would do part one of the job.
For the second part, turning the alarm off after a few seconds, a timer would be needed. A timer as is used for the interior lights of the car could be used for that.

Harald
 
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