Need High Candlepower Beam

arc lamps

Jamie

The HID's advertise 15 million. Simple 10 watt halogen should easily get 3 million. How they get their ratings seem to be a mystery. All depends on spot size. My 500 lumen flashlight is amazingly bright.

Greg

Laser beams are "brighter" in the sense that you get more photons per squar e millimetre in the focal spot, but they won't give you 3x10^6 candlepower.

You are thinking of a Xenon short arc lamp. Here's a useful tutorial.

A 12V DC supply won't hack it. You need a 20 to 30kV spark to start the arc , which initially drops a couple of hundred volts for a few microseconds as it is first sustained as a glow discharge before it gets the tungsten elec trodes hot enough for the arc mechanism to take over.

Zeiss's small xenon arcs need 15V at about 5A to sustain the arc. The unit that I built to drive a bigger lamp needed 20V at 22.5A.

The voltage drop across the arc has a weak negative resistance - in that th e voltage drops slightly as you increase the current - so you need a power supply that regulates the voltage drop to sustain a constant arc current - think pulse width modulation and a filter inductor.

Protecting the pulse width modulator against the 30kV starting spark takes a bit of care. The Southampton Chemistry electronics workshop apparently bu ilt an "improved" version of my power supply after I'd left, with a "better " starter which destroyed all the regulating transistors when they first tr ied it.

You mean like one of these ?

or these ?

rc, which initially drops a couple of hundred volts for a few microseconds as it is first sustained as a glow discharge before it gets the tungsten el ectrodes hot enough for the arc mechanism to take over.

Look in Ebay for HID Xeon kits for replacing car headlights with Xeon bulbs. They have ballasts that run on 12 volts and generate the necessary starting voltage.

Dan

The good old spot lights are having good and quite big chrome plated reflectors, so they collect most of the light of halogen in the spot.

But the lumen wattage performance of halogen is poor compared to LED or HID. So much brighter lights are not a problem......

The highest intense spot I achieved so far was using a 2mm long high pressure arc bow with a tube build for 24W DC. It is running wiht an AC current at 5-6kHz instead to avoid cathode fall regions.

The reflector is always very important in combination with the size of the light source itself. The proper adjustment and mounting is tricky, when smaller diameters are in use. One of the best reflectors for a standard D1S or D2S MPXL bulbs you find for instance at MIL flashlights like

LEDs gives you also impressive spot lights, but only when doing it right: You can get just in the center an impressive blue spot, which is just the blue chip and the yellow of the luminance material is in the outer ring and you wonder why your several watt LED chip is less good than a well designed LED from for instance LEDLENSER running at lower power.

rgds

Joerg

Like Bill said, HID lamps can provide high light levels from 12 Vdc if you use the appropriate step up electronics, triggering supply and ballast.

Your best bet is to Google for an HID handheld spotlight. Or for a rollyour own, build something around an HID headlight conversion kit.

There are more powerful lamps available that are not suitable for vehicular use. But given the limited market, they will be more expensive. Your best bet is to use something built to use a headlight type lamp so replacement parts will be easily available.

never heard of inverters?

Jamie

Cannot find a U.S.A source.

If Electus has it try Jaycar, they are the retail arm and have a presence in USA.

says says about $51 shipped to US metro locations. 5-10 days.

$70 seems to be the australian price, it's even cheaper in UK

in NZ they want crazy mooney.