64665 HLX LL Bulb Testing (36V 400W)

[sylathnie]

I purchased 2 64665 bulbs (36V 400W) to do a little testing. I used an IRF1404 to switch the bulb on at each voltage. The bulb was powered on for a minimum of 10 seconds at each voltage. Here are my findings:

It looks like this bulb could be potentially used with 12 cells if used with a soft starter. (Looks for AW )
It should also be noted that the IRF1404 began heating up quite a bit above 45V. I think I need a bigger resistor between the source and gate legs. I was seeing about 1.2 volts to the bulb even with the "switch" off.

 

[JimmyM]

The IRF 1404 is only rated to 40V. I'm surprised it worked as long as it did.
You need something like the IRFSL3206. It has a 60V rating, comparable current handling, and lower resistance.
You do NOT want a larger value for your gate-source resistor.
The IRFSL3206 has a Vgs = 20V.
So you need the 2 resistors to operate at up to 50V.
Their values should be 4.7K from B+ to the gate and 2.7K from the gate to source. Use 1/4 Watt resistors.
These resistor values give you a pack voltage range of 30V - 50V

 

[modamag]

Nice test! sylathnie.
Did it flashed with your FET switch with 12 cells?

 

[sylathnie]

Thanks for the MOSFET recommendation. I've been looking for my next project. I've finished my HID so I may revisit this bulb again.
I did not actually test this bulb with a pack. My current balance rig will only do 10 cells. I desperately need a better rig too.

It should be noted that at 49V this thing puts out an indescribable amount of pure white light. The kind of light they use in the movies to back light aliens or indicate super powers.

It introduced me to worshipful profanity. :bow:

 

[LuxLuthor]

A reminder to those considering any of the 400W bulbs, that they are significantly larger than the 250W....with the 664 & 665 being REALLY LARGER than the 663. I posted a comparison image in this post.

 

[JimmyM]

A reminder to those considering any of the 400W bulbs, that they are significantly larger than the 250W....with the 664 & 665 being REALLY LARGER than the 663. I posted a comparison image in this post.

Yeah. No kidding. That thing must be huge. the 663 was huge when I tested one for another CPFer. The 665 must be as big as my thumb!

 

[sylathnie]

I would love to see someone create a nice large reflector that would fit these monsters. The large bore of the bulb creates some interesting challenges in fitting a head to them. The standard mag head doesn't even have the depth necessary to contain the length of the bulb.

 

[rolltide]

I am working on a reflector solution, but it will probably be after the first of the year before I finish it. I hope to have pictures of my new creation (ELE II hotwire with large reflector) up sometime in Jan. The main thing I have to do is heat test it. I need to get my AW driver working. Modamag is helping me with that, but it will be after the first of the year until I get everything assembled and tested.

 

[LuxLuthor]

If you can say, what is your reflector source? I'm trying to convince Modamag to have some more of his 4" bored wider, then coated at that bore size so these larger bulbs fit. Don't know if it is cost effective for him to do another run...but I'm pretty sure that further boring the Colossus 4" model will not hold up to the heat at bore edge.

 

[sylathnie]

I would be in for a 4" head with a wide bore reflector. I'm certain that someone with the proper knowledge could come up with the optimum reflector geometry as well.

 

[modamag]

Gang, boring the reflector larger (0.650" ID) to accept the 665 is a piece of cake. Strip and recoating is alittle cost prohibitive.

But what I worry most is the proximity of the heat to the side wall. It's a little too close for comfort.

If we were to design a reliable reflector I would have to make the reflector shallower to move the heat source away from the closest edge.

But doing so will cause the throw/spill % to be less than perfect.

Trade off, trade off.

Any case, I've order a buch of 665 and will test them with a bored out reflector next week.

We'll find out how durable this heavy duty coating is.

rolltide: Your stock driver (even when good) will not work with the 64665, the voltage is beyond the FET's range.

 

[mrQQ]

Gang, boring the reflector larger (0.650" ID) to accept the 665 is a piece of cake. Strip and recoating is alittle cost prohibitive.

But what I worry most is the proximity of the heat to the side wall. It's a little too close for comfort.

If we were to design a reliable reflector I would have to make the reflector shallower to move the heat source away from the closest edge.

But doing so will cause the throw/spill % to be less than perfect.

Trade off, trade off.

Any case, I've order a buch of 665 and will test them with a bored out reflector next week.

We'll find out how durable this heavy duty coating is.

rolltide: Your stock driver (even when good) will not work with the 64665, the voltage is beyond the FET's range.

Did you ever had a chance to test those reflectors?

 

[LuxLuthor]

Did you ever had a chance to test those reflectors?

+1