We were at a tag sale and I saw a 6 foot blow up pumpkin for $10. It looked to have little use so I grabbed it. I got home and found he 5 bulbs inside were smashed up a bit. That's OK since I wanted to add an arduino controlled RGB LED chip to it. I just cut off the string and put a 110V plug on the leads coming out of the motor housing.
Step 1: Mounting It to the Pumpkin
I used an old Pentium III heat sink to mount a 50W RGB Led and epoxied the series resistors to the heat sink. This made it easy to use the generic light controller from my other instrucable. I live near an active airport so I used a 24V supply instead of the 36V supply I selected the resistors for. I started to think that a 6000 Lumen strobing light in my front yard might not be such a great idea.
I used a star shell from a dollar store closet light as a diffuser. I just wire tied it over the top of the LED assembly. a couple of mini bungee cords hold it all to the fan housing. the power supply connects the the 110V socket on the old light string wires.
This same controller should make a nice snowman too. I just haven't been able to find one of those cheap enough yet.
Step 2: Halloween Night
Here is the pumpkin in use on Halloween night.
Step 3: A Smaller Version for the Real Pumpkins
I made a smaller version for the real carved pumpkins. These only used 10W LED's wired in parallel. Even at that we had to point the LED's at the rear wall of the pumpkin so it wouldn't blind people walking up to the house. I placed the series resistors on the back side of some to-220 heat sinks and mounted the LED's to the front side. They were just allowed ot hang in the pumpkins. this one used a 12V wall wart for power.