This can be a Useful Monitor for Tail Light or Brake Lights in a car.

This circuits can light an LED on your Dash Board, If the Bulb burns out.
Or it can Turn Off an LED on your Dash Board, if the Bulb burns out.

It CAN't operate Both LED's at the same Time.

This Circuit Creates a Small Voltage Drop though a Diode to detect if the lamp is working or Not.
But this Small Voltage Drop Should Not Affect the Brightness by very much.
Probably Not Even Noticable.

This voltage difference, Drives an TL071 as a Differential Amp to light the LED.

I can supply the PCB and Most Parts.
But Not the Diode.

You need to buy a diode that has a Greater Current Rating than the Bulb.
Just a 50 Volt Rating is satisfactory.
A 1N5400 (Rated at 3 Amps) will probably be good for 1156 or 1157 Bulbs.
(But I Don't stock these in any great Quantity.)




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  The Schematic Circuit.

  The PCB.

   Picture Overlay.





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 Chemelec 
 *Copyright © 2015*