Possible source of CHEAP HID bulbs/ballasts?

Hello,

I'm curious if anyone has tried using automotive HID bulbs and ballasts for DIY lights. On Ebay, they seem to be going for $80-$200 per pair (eBay Motors: HID XENON CONVERSION KIT BULBS + BALLASTS H1 6000K NEW (item 290202143892 end time Jan-30-08 19:01:22 PST)). What's also interesting is that these are available with color temps ranging from 6000k to 20000k.

Seems like $80 for two bulbs and ballasts is a pretty good deal compared to prices I have seen elsewhere. Has anyoen else tried this? Besides the obvious issues of needing to design and build a housing for it, can anyone think of a reason not to give this a shot?

Thanks,

Mike

Edit: As far as I can tell, most of what I've seen on Ebay is 35w ballasts.

Some HID bulbs are supposed to burn in a certain position. I'm not sure about the automotive HID's but it is definitely something you should find out. Try and get the smallest ballast you can find.

$135 automotive HID kits

Personally, I would go with LED; although they are not as efficient as HID, you don't have to worry about breaking or burning out a bulb and you can turn them on and off without worrying about destroying the bulb.

$10 cree led emitter

three of those emitters are bout as bright as a 18W HID. They are pretty darn cheap, and they are pretty small. They also have a good input voltage range.

$90 10 Ah NiMH battery pack

Good capacity battery pack for the money and they aren't too big.

You can buy the Welch Alan bulb and ballast for the same price.
Those are the bulbs dive rite uses. You can also get Bright Star bulbs and ballasts.

They are smaller and better suited for the purpose.

Well, I've looked into various LED options, and I don't think I can get as focused a beam with LED as I would like. Besides that, with prices as low as $80 for two HID bulbs/ballasts, thats cheap enough that I won't be terribly concerned about longevity. If one can make it through a season, that is good enough for me.

I haven't heard of the bulbs being position dependent before. Do you have a source for that information/somewhere I can go for more information?

The size of the ballasts that I've seen on Ebay are roughly the same size as in the current Halcyon 18w lights, so size is not really a big issue. Something to be aware of with the smaller ballasts however is a possibly reduced output and input range.

I'm not really concerned about the design or construction of the light itself. I'm a college student, and have access to machine shops, electronics equipment, etc. I know I can get a light built and working well, I'm more interested in hearing specifics about automotive HID systems in general (and possibly these bulbs specifically). I know that some DIYers use the TrailTech HID bulbs, but those are considerably more expensive.

Thanks,

Mike

I agree LED's just don't have the punch, yet.

Automotive bulbs use a MUCH higher ignition voltage than a standard HID bulb.

fppf:

Automotive bulbs use a MUCH higher ignition voltage than a standard HID bulb.

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The input for most of the ballasts I've seen is 9-16v, which I can easily manage with a variety of battery options. The ballast is what will control the voltage and get it up to the level required for the bulb to ignite, correct? As long as I can keep the ballast happy, and the bulb and ballast are matched, I don't see a problem. Am I missing something? I can also put together an electronic monitoring circuit that will control voltage and current levels and probably extend battery life, but that's an entirely different topic.

I'm also not looking for massive burn times, necessarily. I'll take the largest I can get, but I doubt I'll be in the water for more than 2-3 hours on a dive, and carrying spare batteries is not a problem for me (for repeat dives). I'll eventually be getting into cave diving, and will likely purchase a professionally made light before then. This is simply a moderately cheap DIY project to last the interim (and be a fun distraction).

Even as a poor college student, I'm fairly comfortable throwing $80 down just to play with it. If it turns out to be a total loss, I won't be terribly hurt. If anyone knows of specific reasons not to even bother, I'd love to hear them. Otherwise, I'll probably end up ordering a set and seeing what I can put together with them.

Thanks,

Mike

The LED's that I mentioned have a 6* beam angle above water, you are going to have a hard time finding a reflector for a 35W HID bulb that can do that. I was also going to make a HID light with the automotive kits, but the LED's are so much easier to work with.

The ballast uses the same input votage, but the ignition voltage for the lamp on Automotive bulbs is 20,000 volts. This is to support the hot starting. The ballast also over drives the heck out of the lamp to get it to start up faster. Just make sure your very careful and fully understand how to work with these things.

Yes LED's are much easier to work with.

marchand:

The LED's that I mentioned have a 6* beam angle above water, you are going to have a hard time finding a reflector for a 35W HID bulb that can do that. I was also going to make a HID light with the automotive kits, but the LED's are so much easier to work with.

Click to expand...

fppf:

Yes LED's are much easier to work with.

Click to expand...

Easier to work with, but not as bright. You can put them in an array, but then you get a wider spread. Let's not turn this into another HID vs LED thread, that is not my goal. I want to find out more about this type of automotive HID.

fppf:

The ballast uses the same input votage, but the ignition voltage for the lamp on Automotive bulbs is 20,000 volts. This is to support the hot starting. The ballast also over drives the heck out of the lamp to get it to start up faster. Just make sure your very careful and fully understand how to work with these things.

Click to expand...

Can you give me more information? I don't plan to modify the ballast at all unless absolutely required, so do I need to be concerned with the voltage between the ballast and the bulb? I'm basically treating that as a closed system. It was my understanding that as long as I can feed it the correct voltage and amperage, the ballast will handle the rest. Now, I *COULD* have a friend design a circuit to act as an intermediary between the ballast and bulb to ensure startup and shutdown is done smoothly to extend bulb life, but I don't really think that is necessary right now. If I'm going to do that, I might as well have one of my electrical engineer friends just custom build me a new ballast. As I said, if I can get a season or more out of a single bulb and ballast, I'll consider it a good investment. So maybe 100 hours out of a bulb and I'd be happy enough. From what I've read, these will last a great deal longer than that.

For comparison, what voltage does the Halcyon ballasts (Welch-Allyns still?) drive their bulbs at?

Thanks,

Mike

5000 volts for ignition, 80-90 for drive. Drive voltage in steady state is almost the same, its ignition thats huge.
You just need to becareful with the wiring between the bulb and ballast. You can not just use any wire. Most Automotive systems have a seperate ballast and ignitor circuit. The welch alan system is all in one.

I would not go into circuit design. Unless your friends have a lot of experiance with buck boost converters and high voltage drives it is not as easy as you think. I'm designing my own ballast, but thats because no one makes one to drive the bulb I want to use on DC power. I already have many hours and over a thousand bucks tied up.

I'm not starting an HID/LED argument. Just stating there easier for people that are not electrical eng. and fully understand how HID bulbs work. If you mess up, they can kill you.