Adding 'eyes' to the Mack truck bulldog

Project: Adding red eyes to the Mack truck Hood ornament
[This is also up on instructables]  
What? :The hood ornament
Way back when, our family visited the mack truck factory for a tour. I ended up getting a hold of a Mack hood ornament. It didnt have lights but its a relativley cheap and very simple addition.

    [This project is available in a pdf for easy printing/ viewing]
Part 1: Getting The Goods
Part Site Cost
red t1 led's allelectronics.com / goldmine electronics.com /burger king toys ~$1.00 / free
Resistors desolder from old hardware / radioshack
$2/ free
the Mack truck bulldog
Available at the Mack truck facility / ebay/ junk yard ~$35

1: Prepping the subject As the bulldog is polished aluminum, i clampled it in to a vice using 2 pieces of scrap wood to prevent scratching.
2: The center of the bulldog is actually a hollow slot going from the head to the mounting points. I drilled 3/4 inches in to get to the hollow area.

another shot of the eye hole
4: Simple electronics   the car battery is assumed to be 14v. (assume the worst). the forward voltage drop of a red led is about 2.2 V. The expected current is about 5 milliamps. 14-2.2=11.8V. Using R=(V/I) the correct R value should be approximatley (11.8 / .005) or 2.3K.  use any value you deem apropriate for your project. (I actually used something like 1.8K ohm 1/4 watt resistor)

5. Solder and package I used 22 gague wire to wire 12 v to each led. then i connected the common ground to the aluminum via a high temperature solder point. finally i used some old wire from a broken lamp for the 12v line that would be fed by the vehicle. I used a piece of broken bike tubing to the bottom to prevent it from scratching the vehicle.

bottom view.
6. Epoxying everything in place



This article as a pdf file (easy for printing)

Rensselaer Polytechnic Institute 
Electrical & Electrical Power

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