HID DIY, working proto + Pics

brianb00 · 02-11-2007

Hi - have some photos of comparison of the 10watt halogen and the 10watt HID along side each other.

Shots were taken a few minutes apart using Canon A540. Manual mode, 1.5 sec exposure, F 2.6. Conditions were identical.
The bike in the scene is 35' away and the white fence about 50' away.

The photos are at the bottom of the page.

The HID is obviously considerably brighter.

Hi,

I am nearing completion on the ballast for a home brew hid lamp using the Welch Allan bulb (10w). THought I would share a few pics of the proto types that I have traversed along with the first version of packaging for combo light of two mr16 lights, one HID, one LED. The concept is LED for climbs, HID for descent. Where I ride we only have long continuous ascents followed by the descent.

As has been mentioned here in the past, the HID ballast is an interesting and time consuming challenge. Lets just say that what started out as a quick project to avoid the purchase of a $500. lamp has turned into several months of spare time spent tuning a design, purchasing prototype parts, blowing up a perfectly working 12 volts power supply, purchasing an oscilliscope, winding transfomers, finding myself attached to the hot end of a few kilivolts, and toasting the wifes table cloth during a demo, ...etc. Needless to say the $500. seems like a bargan.

However, that is all history. What I have now works quite well for supply voltages from 14 to 10 volts maintaining a very stable operating point for the HID lamp. At this point I am about to move to miniturize what you see in photos and do a small prototype run of the ballast on a reduced size circuit board. My question for the crowd here is: Would anyone be interested in exchanging a hid ballast hardware built on a small circuit board for a mechanical design that looks a bit sexier than assorted plastic plumbing parts flying in close formation ? I have some interest in doing a kit build where a number of participants share their expertise to get a few of these put together. Some sort of "peoples HID".

If there is interest out there among you DIY-ers drop me a line.

Regards,
Brian B.

presslab · 02-11-2007

Hey that's really cool. What IC did you use for the switching supply?

brianb00 · 02-11-2007

Hi Presslab,

Like my bike the IC is a retro blast from the past. The grand daddy of all PWM chips. A 3524. NExt generation is going to move up the food chain to something a bit more recent. I particular, a new design has different drivers that should allow me to push the efficiency up over 90%. THere are also some interesting chips used in laptops that might shrink the parts count a bit, looking at those as well.

brian

presslab · 02-11-2007

Cool, many moons ago I made a forward converter with a SG3525A... Powered an ATX motherboard from a car battery. Wound my own xformer with some E cores scavenged from an old xformer by heating in the oven.

With modern mosfets you should be able to crank the switching frequency to 500 kHz or more to get the xformer size down while maintaining efficiency. What are you running at now?

brianb00 · 02-11-2007

With modern mosfets you should be able to crank the switching frequency to 500 kHz or more to get the xformer size down while maintaining efficiency. What are you running at now?[/quote]

At the moment the freq.is a low 20kHz. Xfmrs are home rolled, had to characterize some surplus cores to get it correct. Next generation will raise the freq. Already using mosfets. Have some new cores that should save a bit of weight. The electronics can be cut way down with component optimization and surface mount.

In any case I have to hurry this along, LED's are going to put my $100 HID bulb out of contention for light vs power.

brian

presslab · 02-12-2007

Well, the fact you made your own ballast is quite a feat in itself. I wouldn't be too concerned if it's the most efficient thing out there.

The downside of higher switching frequency is more loss in the MOSFET while the transistor is switching. MOSFETs are continually improving and with lower capacitances they are switching faster and faster.

Wish I could help you with the mechanical stuff, I'm just getting started in that myself.

brianb00 · 02-12-2007

Quote:

Originally Posted by presslab

Well, the fact you made your own ballast is quite a feat in itself. I wouldn't be too concerned if it's the most efficient thing out there.

The downside of higher switching frequency is more loss in the MOSFET while the transistor is switching. MOSFETs are continually improving and with lower capacitances they are switching faster and faster.

Wish I could help you with the mechanical stuff, I'm just getting started in that myself.

Well I have made a couple halogen enclosures with pvc plumbing, as seen around this forum, and once they are painted black people tend to think they are commecially made. I had two guys ask today about them on a peak we climbed in rain soaked trails. They tend to stare at them and then realize that they are PVC pipe. So maybe my little kludge enclosure will be fine. But I hoped to trade one skill for another. Some of the lights I have seen here look as good or better than anything you can purchase.

I do a bit of composite fab. so if I have the time I may try to mold something with carbon fiber just for the look.

brian

brianb00 · 02-19-2007

There are a couple photos of the DIY HID lamp I designed/built. Packaging could be improved but it is all operational.

One bright little lamp on ride down the hills in my area.

UrbanPounder · 03-02-2007

brianb00 - LOL R&D is expensive. By the time I came up with this final setup I had been through some crazy light/battery configurations. Could of bought a expensive HID and spent more time riding. The pics are of a aftermarket harley davidson marker light (1950's) gutted and fitted for a MR16 halogen. Any harley shop will have these in a bin somewhere. $11.00 cheap for something the halogen won't melt. If they ask for $20+ for one just smile politely and say "no thanks" and go to another harley shop. Its more the principle than a money saving move. Up to $19.99 you call it. Anyway, its mounted to a spare plastic holder thingy one gets with any bicycle goodie. I have a box full of em. You can see how its fitted. First you gut the thing. Just open it and bend off the tabs with the light socket and toss. Toss the orange or red lens too. Don't try looking through it. Just toss it..... I kid. Good luck.

More info for those that use a MR16: Wiring, used a female DC connector and attached it to the proper (only) two prongs on the MR16. Large 2" dia rubber "O" ring (approx) or two set behind the MR16 as you press it in the body. A rubber gasket came with the light, use it between the lens cap and the MR16. Put on the lens cap and clamp it. The body's taper will snug it up tight. Drill a couple of screw holes now (inline) through the cover and the body and use the smallest and shortest sheet metal screws you can find (1/8" long my be too much) so not to hit the glass. Talkin tiny here. Put screws in. Done.
Tips: Find a gold plated anything that will bend around a nail or something the same size as the prongs in the MR16 and solder them on the wires. No corrosion. A good source would be a radio shack gold series 1/4" mono jack. You'll see. A battery that will run a light like this I'm posting on another thread. Good luck.

UrbanPounder · 03-02-2007

The pics. Here.

brianb00 · 03-02-2007

Hey,

Thanks for the ideas. The shots look great. My present plan of attack is a Maglite modified. I will stop bye the local Harley shop and see if I can find one.

Brian

UrbanPounder · 03-03-2007

Ya Brian, I did that Maglight thing too. Do you know the end cap will (with a thin rubber one wrap from a tire tube) press fit into the back of the mag head making for a solid sealed housing. The mag head is so thick, you can drill and tap it and not need any other hardware than a bolt to mount it. ok

brianb00 · 03-18-2007

Finally shot a few photos of HID vs Halogen for this DIY project.

Low_Rider · 03-19-2007

Nice work Brian!

brianb00 · 03-19-2007

Quote:

Originally Posted by Low_Rider

Nice work Brian!

Thanks. My packaging is still in PVC but have added a 'heat tube' to move the heat away from the bulb.

The entire proj. has been a kick, I sure wish I could find someone with mechanical interest to improve the packaging.

These bulbs are awesome, I am looking at jumping this to a 20 watt bulb. I can then smoke the sage and manzinita along the trails.