Osram Halostar IRC lamps NOW in a HOST w/beamshots

[JimmyM]

JimmyM: Thanks for sharing your experiences on the 64458. To be honest, I had not even thought about this one.

Yeah. It's 4000 hour life means you can really overdrive it. But it also means you really HAVE to overdrive it. It draws almost exactly 10 amps at 20+ volts.
I mean 20+ a little. 20.1-20.2-20.3. 17 cells at 1.2v = 20.4. So at 10 amps, these 4 Ah cells sag a little, but after a minute or 2 they're at 1.1v-1.15v. They can't hold 1.2V+ consistently at a 10A load. But even at 1.1v each, it works out to 8,500+ Lumens. At 20.1V it puts out ~11,000 lumens.

Direct drive a 65W IRC on 15 well rested 2/3As or As @ 18V you get 5,800 lumens.
Direct drive a 90W 64458 on 15 2/3As or As hot off the charger @ 18V+ you get AT LEAST 7,400 lumens.

With these numbers, it's worth at least trying.

 

[LumenHound]

winny, what about something like this for a soft start with a 18 volt battery pack?

The Osram Halostar IRC beats the completion just about always, but you need to go down in voltage if you want to go with direct drive.
There are few efficient 24 V lamps, but Osrams 24 V, 250 W Xenophot comes into my mind.
There are lower power versions of it too IIRC.

Also, I should correct myself. You _might_ be able to start it at 18 V, but the chance if instaflash is very very very high - not worth the risk in any way.

 

[JimmyM]

For no regulation I was thinking about just using a 556 and a small mosfet. It would be PWM softstart with an end result of a 100% duty cycle. The mosfet would have to dissapate almost zero power/heat. The ouput power would still follow the RC charge curve. Maybe the length of the ON pulse could be based on a reverse RC charge curve. Then the power would start off ramping duty cycle slowly than quicken its rate of increase until it's 100%.
I haven't had the time to really look into it. But I LOVE PWM.

 

[andrewwynn]

the lamp i'm aiming for is the 64367 .. running at 28+V.. 325W and just about 10,000L out the front. it should be quite a sight.

Back to IRCs though :-D.. i'm amazed how much i like the 50w compared to the 65.. i run it in a 2D host with 16x2/3A (a couple dummy spacers in a 6x3 config and quite a trick to turn it on n off not to mention fit them in!).. however it's a cake-walk to duplicate that solution in a tri-bore 3D.. in about a month or two i should be able to start offering the smartpak for sale to hold the cells together.

-awr

-awr