Home made HID Spotlight

[cmacclel]

I'm thinking about putting something together using a projector setup from an A6 Audi or another OEM projector style HID. I have a few questions

Won't an HID setup with a projector style lens be brighter than one with just a reflector??

Does the Factory ballasts (Hella) have a low voltage shutdown and thermal protection??

I was looking into battery packs and see that the Nimh d size battery is rated ar 8000Mah and the c size is 4500Mah. The thing that gets me is I just looked up regulsr duracell alkalines and the d cells are rated at 15,000Mah and the c cells at 7800Mah. Anyone want to ponder on runtime with any of these battery's??

Also how many amps does the 35 watt HID's draw?? 2.91 amps???



Thanks Mac

 

[zmoz]

Alkalines will only give you that high of a rating if they are used very slowly. In something like an HID light, the NiMh will last much longer, as they do good on high drain devices.

 

[highlandsun]

Startup current is much higher, maybe 5-7 amps for <1 second. But yeah, 35W divided by 12V gives you 2.9x amps.

Low-voltage shutdown? Not sure what you mean; the ballasts will operate from as low as 9V and as high as 16V AFAIK. What thermal protection? An automotive component generally has to operate from -10C to 100C, so what thermal protection did you have in mind?

There are higher capacity NiMH D cells now, 11000mAh or more.
So you'd need a pack with ... a string of 10 in series and 3 strings in parallel to provide 1 hour of runtime. You'll have to check and see if they support a pulse discharge of 2C to handle the startup, I think that works...

As far as projector vs reflector - I doubt that either type of automobile optic will be very good for a handheld spotlight. Projector optics are not "brighter", they just provide a tighter focus of the beam pattern. The beam pattern is crafted to illuminate a horizontal swath, with a sharp horizontal cutoff to prevent glare problems for oncoming drivers. For a real "spotlight" you'd do best with a regular parabolic reflector assembly that uses a fluted lens, and discard the lens. If you use a lamp with a multi-surface reflector and a flat "lens", then you're going to get the same beam pattern as the projector. These are great when you need to illuminate the pavement in front of a moving car, but hardly useful as *spot* lights.

 

[larryk]

I just finished building a HID spotlight, and because there is no low voltage shutdown sensor like the X990 and Maxabeam, you will risk draining your Nimh or Nicad battery pack down much lower than recommended. I would suggest you go with a 12 volt SLA battery. They are inexpensive and many sizes to chose from.
Larry.

 

[yuandrew]

Any pictures Larryk? I'd like to see this thing running. Do you have any thing to compare it with?

Hmm, I would also like to build one maybe using a Night Blaster handheld spotlight my friend has. I don't have the money or time on hands to do this though. Anyway, his light doesn't have a battery in it and there is probably no room for the inverter/ballast. The light connects to a car battery terminals with a pair of large alligator clips.

 

[yuandrew]

Test it out side by side with both a Maxa Beam and the X-990 I just noticed you have these lights

 

[yuandrew]

Back again. I looked at suvlights.com for some ballast spec sheets. I couldn't find the one for the Hella or Philips one but the Panasonic one cuts out automatically if the voltage falls to 6 volts or below.

 

[larryk]

Sorry, no beam pictures yet, I used a Collins Dynamics CD-12 Magnum hand held spotlight for the host. You can view the spotlight at this address, http://www.wattco.net/havisshields/collinsportable.html I chose this because of the large reflector (8.5 inches) that gives it a nice tight beam. The cost of the CD-12 Magnum is very expensive ($ 200.00) but is made very nice. I am still working on a box, or maybe even a camcorder bag to house the battery, ballast and igniter. From playing around with it a little I would say it will throw about 3 times farther than the X990. If you plan on using a long length of wire between the bulb and igniter you have to go with something that is very well insulated. Trust me I know, after many trials and error I found that co axial cable works, my cable is 9 feet long Larry.

 

[**DONOTDELETE**]

larry,
the Collins is a great idea for the host -- 8.5 inches and a tight beam sounds excellent..looking forward to the pictures..
mm wonder if I could get just the reflector.. /ubbthreads/images/graemlins/thinking.gif

 

[larryk]

Give them a call, they do sell parts.

 

[cmacclel]

My 35 / 50 watt Ballast along with 2 8" Bosch housings (one spot and one flood0 will be here Friday so I can start experimenting. Larry why does the wire need to be very well insulated?? Also how did you use coax??? What type of connectors did you use??

Chris

 

[larryk]

Because of the high voltage at start up. I even tried Carrol speaker wire that appeared to be well insulated, but would still arc thru the insulation. I took some comparison photos with the X990 and Maxabeam at close quarters ( 7 feet from the wall, but I do not know how to post them.
Larry.

 

[cmacclel]

If you wouldn't mind I would like to see them. Can you E-Mail me them??

[email protected]

 

[LEDagent]

LarryK,

I can post them if you want to email them to me.

 

[larryk]

Photos sent, these are at 7 feet from the wall.
Larry.

 

[pwell]

[ QUOTE ]
highlandsun said:
There are higher capacity NiMH D cells now, 11000mAh or more.
So you'd need a pack with ... a string of 10 in series and 3 strings in parallel to provide 1 hour of runtime. You'll


[/ QUOTE ]

If NiMH D cells are now 11000mAh (11Ah), then you only need ten of them in series to give you 12V and about three hours runtime (a bit less because batteries are usually reated at (1/20)C.

10 would weigh about 1.5 kg. Those 11000 batts are nice but mega expensive still.

 

[PsycoBob[Q2]]

I'm trying to save up for a similar project.
I'll probably start off with Lead-Acid, and work on a better battery later.

Perhaps using high-current batteries inside the head of a large rechargeable spotlight. Maybe a high-current NiCd AA or 'A' pack, to provide startup power and enough for a few minutes runtime, with a belt-pack for a larger separate battery.

Most of my design work revolves around how much room the bulb/reflector ballast/ignitor set takes up, and I won't know until I get them. The insides of the spotlight-donors I have are all designed for exactly what they do, and have little extra space.

 

[larryk]

I ordered a Vector aluminum spotlight, the one with the battery on top and the other battery in the base. I think I can use my other ballast, igniter and bulb on top with the upper battery remove and change out the battery on the base to a 12 volt battery. Will see when I receive the Vector this week.
Larry.

 

[highlandsun]

pwell - oops, you're right, I slipped a decimal place in there. Even those 9000mAh D cells would be OK for this job.

 

[cmacclel]

My light is fully operational and the results are pretty good! I would say a 30% increase over the X990. I'm using a 8" reflector with a light stainless steel housing, A Phillips 4300k D2S bulb, and the Kenrad 35/50 watt ballast. I have everything mounted nicely in a 30 cal. ammo can with a SLA 7ah battery. I have an on off switch and a Hi/Lo switch. If someone can host a picture E-Mail me at [email protected]