185Mcd 240W UHP Build

[Alexander47]

Hello,
I'm Alexander from Germany and new at the forum.
For quite some time I was reading here without a Account.
Im especially interested in spotlights and unusual equipment.
Besides some custom HID builds I have a AEG XSW 30 Searchlight aswell.

Here I wanted to present my latest build, it is somewhat low cost and has a super high range.
It works without expensive optics and only a 300mm Fresnel lens for like $20.

As a front bezel I used a 3mm steel plate and drilled some holes on the milling machine.


The leftover parts from the middle will be the back of the frame:


Since it has to be somewhat lightweight it is a basket construction from 3mm steel wire.


Lamp and Ballast are mounted in some cheap drain pipe.
The one on the left is a Osram P-VIP 240/0.8, the right one a Osram P-VIP 180/1.0
The first part is the wattage and the second one is likely the arc gap.



The basket was wrapped in some acoustic foam where air can pass through it.
At the left end there is a radial blower which pulls air over the Lamp and the Ballast inside the pipe.


In the front there is the 300mm fresnel lens with a focal length of 380mm.


The lamp has a ellipsoid reflector which has two focus points, one between the electrodes and one around 20mm in front of the lamp.
So the optics work somewhat this way, so there is no need to remove the stock reflector from the lamp.


I added a mount for a tripod so the lamp could be positioned:



At 18:00 it was getting dark so a first test was done, the brightness is somewhat similar than to the eye.
The target(some hay bales) are 1070m away.


At 19:00 it was basically night.

 

[Alexander47]

A zoomed in view:
The bales are about 6m wide, total beam with is about twice that so 12m.
With a distance of 1070m this gives a divergence of 0.65°


The next day I checked the bales for damage, but they are still fine:


While at that place I was looking for the next target.
A wind turbine about 5km away should be it.


From source to target:


Zoomed it as much as the camera would do:
You can see the red position lights mounted at the turbine of all four turbines.
But only one turbine is visible for the eye.


Here i did some measuring the light density at a distance of 127m.


Corrected to 1m one lux meter would show 180 Mcd and the second one 190 Mcd.
With that i would call it 185 Mcd.

The core spot is about half the size of a door at that distance.



As power supply I use a sine wave inverter connected to a 8S 12Ah LiFe battery in my backpack.
The high voltage DC is pulled from a computer power supply with a active power factor correction.
With that I can use it on the mains too.

Total weight for the Light is about 5kg, Inverter and battery excluded.

I'm planning on some comparison pictures with the AEG XSW30 which should be known here in the forum as BVH has posted some great pictures of it here.

 

[hamhanded]

That’s some solid engineering! Nice work!

 

[IlluminatedOne]

That is really impressive, great work. Love seeing these sorts of projects.

 

[BVH]

Yes, these self-built threads are always fun to see! Great work!

 

[hahoo]

did you say 185 million cp, or lux?

 

[Alexander47]

did you say 185 million cp, or lux?

185 million candela = 185 million lux @ 1m
Measured at 127m were 11500 lux.

 

[Alexander47]

Here is a comparison between the AEG XSW-30 tank searchlight, the here discussed lamp and a similar one with 320W UHP and 220mm Fresenel.

 

[BVH]

I know how far my XSW 30 beam travels and the amount of light in the beam so seeing this comparison is quite interesting. The XSW 30 lamp is a pure Xenon fill and is running at somewhere around 450 Watts if I remember correctly. Or is it 420 Watts? What is the gas fill of the UHP lamps? I would suspect there are a lot more Lumens being produced per Watt in the UHP lamps.

 

[Alexander47]

Yeah 450W is correct for the XSW-30.
Pure Xenon Lamps give a very good CRI and are immediately at full brightness after igniting, they are however quite inefficient.
In the range of 25lm/Watt I believe.

UHP / UltraHighPressure / UltraHighPerformance lamps only use mercury as far as I know.
They run at even higher pressures than the XBO lamps (200 bar and above).
Efficiency is certainly better than the XBO Lamps with >60lm/Watt usually.

 

[sven_m]

What is the gas fill of the UHP lamps? I would suspect there are a lot more Lumens being produced per Watt in the UHP lamps.

It's just mercury for the emission, and some halogen for recycling vaporized tungsten back to the electrodes.

The idea for developing this HID type: plasma temperature is limited by the ionization energy. Higher plasma temperature allows for higher luminance. Now, mercury has a higher ionization energy than metal halides (e.g. automotive HIDs, used in Polarion/Lemax/FF).

But mercury vapor is atomic at usual pressure levels and thus only shows emission "lines". That means bad light quality. However, at very high pressure, mercury molecules also come into count. The pressure in a running UHP bulb is about 200 atmospheres, and mercury molecules have a partial pressure of roughly 10 atmospheres. This allows for emission "bands" instead of only "lines". And the high pressure/temperature also widens up the emission lines.

It was developed especially for small projection systems, beamer. It comes with some difficulties (inverter ballast with 400 DC input, UV, high pressure bulb, low startup time). I would be surprised if there was ever a commercial UHP thrower. But if you handle these issues with a self-built type, then it's an extremely fascinating thrower source: compact, yet lots of luminance and lumens. Efficacy is also better than with pure xenon. Reminder for non-arc-nuts: Is this the next generation source? It has much more boom for the watt. But pure Xenon is relevant anyway: Much more overall lumens possible, maximum CRI, instant on/off, infrared source-> light houses, cinema, tank and helicopter lights, ... And in search lights like Maxabeam, Megaray & Co.