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.
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.
All done and put together.
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.
Here's the final setup with led's soldered in place and a 1.5V watch battery used as the power source.
And when I close the contacts......
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.
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.
This is the end product:
Not too shabby...
ph2t.
Custom Headlights....
Linear Mode
