Custom Headlights....
 

This is a light mod I've worked on as a side project from others. In building my knightrider lights and custom h-bridge and other goodies I've come to realise the power and potential of these DCDC converters.

The DCDC Converter

A DC-DC converter allows me to take a low voltage, say like 1.2V (our car's battery for example) and convert it to a higher voltage like 3,4 or even 5V. Why do this? Well let me tell you that there's not much stuff out there that runs on 1.2V that's for sure. You might argue that the car runs on 1.2V and it does BUT the receiver circuit in the cars uses a dcdc converter as well to provide the RX2/6 chip with 3V! So there you go!

LEDs, the good, the bad, and the just plain crap

There's many different LED's out there. Most of you have even probably used some before in making headlights, underbody lights and so on. LED's come in all shape and sizes, mostly 5mm and 3mm. The perfection light kit for example uses 3mm LED's. Then there is surface mount LED's, these buggers are really small and are fairly bright when comparing them to their larger cousins.

The problem with LED's is one of voltage. To use some kickarse blue or white leds requires a fair bit of voltage, usually from a minimum of 2.6V to at times over 4V! This is why you need to use an external power source like (in most cases) a 3V lithium battery. The car battery is only 1.2V and prolly won't power any led natively (even RED led's need like 1.6V min to operate).

Another issue is not technical but one of looks. To drill two huge holes to fit 3mm leds can detract from the overall look to the car, using surface mount led's enables you to glue them on the inside of the shell and let them shine through. Obviously you need your headlights to be clear to start with for this to work. This is just a personal preference thing with me.

So here we go

Here's all the parts for the circuit including a custom pcb I made for the job. Using my good old "Steering Knuckle Size Comparison Test(tm)" you can get an idea as to it's size.

http://www.prahranpianos.com/bit_g/lights_c/lights1.jpg

As some of you have probably done from the mosfet mod, I like to glue the parts onto the pcb first before soldering them. This helps to keep them still as I solder the terminals.

http://www.prahranpianos.com/bit_g/lights_c/lights2.jpg

All done and put together.

http://www.prahranpianos.com/bit_g/lights_c/lights4.jpg

Here are the LED's I'm using. They are beasts! Ultra bright white leds rated at approx 300mcd for 30mA and they need 3.9V to operate! Dang!! So small compared to the 3mm yellow led next to them.

http://www.prahranpianos.com/bit_g/lights_c/lights5.jpg

Here's the final setup with led's soldered in place and a 1.5V watch battery used as the power source.

http://www.prahranpianos.com/bit_g/lights_c/lights6.jpg

And when I close the contacts......

http://www.prahranpianos.com/bit_g/lights_c/lights7.jpg



I've choosen my Skyline 2000 pullback shell 'cause it's a nasty piece of work that needs some headlights.

As you can see in the picture I have scraped away the silver coat on the inside of the shell that was obscuring the light holes. This is on the right hand side of the picture, left hasn't been done yet.

http://www.prahranpianos.com/bit_g/lights_c/lights3.jpg

As you can see here, I've used some bluetak to quickly rig up the lights. On a presentation version I superglue them in place and then paint the area with a thick black gloss to ensure the lights only shine out through the front.

http://www.prahranpianos.com/bit_g/l...c/lights10.jpg

This is the end product:

http://www.prahranpianos.com/bit_g/lights_c/lights9.jpg

http://www.prahranpianos.com/bit_g/lights_c/lights8.jpg

Not too shabby...

ph2t.

how did you make the dc to dc converter?

Do you mean the circuit design? Or the phsyical setup? I believe I detailed the physical setup quite well in the original post. The schematic is as follows.

http://www.prahranpianos.com/bit_g/hbridge/dcdcconv.jpg

ph2t.

Dood, I would pay you up to $15 for one of those. Would you do it?

Sure, see this thread for details:

http://tinyrc.com/forums/showthread....threadid=12746

ph2t.

Outstanding!

sweeet ph2t........how does this affect runtimes??

WOW! Great job, I like it! As soon as Namuna sees this, you can say "Bit Science" for sure!

Well this puppy sucks about 30mA from the car so yes it would decrease runtimes. At a guess I would say about 10%-15% decrease since the car sucks up to 250mA off the battery under normal loaded conditions. This is based on the scenario where you have put the lights pcb on to the car and running it that way.

Using a lithium or a watch battery would negate this since now it has it's own supply.

ph2t.

wow those look cool, nice job...it makes that skyline body look pretty cool

cool dude, i wish i had the money to buy that sort of stuff, i am at the moment saving up for a real car, lol. only a crappy thing that i can do up and mod the hell out of, something like a 3000gt or escort.