Osram 64458 on 16 cells

[JimmyM]

I had a 65W IRC running on 15 1/2D NiMH cells but blew the hotdriver. I had orderd a few 64458s to mess with (90W, 12V, 4000 hours). So i pulled the switch from my Mag138 and swapped out the burned HD.
I figured, what the heck. The worst that can happen is I instaflash a bulb.
So I dismantled the switch and cleaned and slightly modded an already modded switch. OK the moment of truth. Hit the switch and lit the '458. No pop! Wow is this sucker bright. My DMM showed 18 volts at startup which began to sag to 17.8, 17.7. I hadn't charged in a while. So I charged up the pack and ran it again. No flash. The DMM showed 19+ volts at start up then it sagged slowly to about 18V and held pretty steady. OK. Cool. So I figured, alright let's try a 16th cell. A fresh 16 cell pack lit the '458 and held pretty steady at 19.3 volts.
AWRs hotrater rerates the '458 to +175W at 19 volts. Now all I need to do is build a 16 cell pack (3x5+1) out of Elite1500s to fit a tri-bored 3D I have.

 

[cnjl3]

Yikes!
You better sell me your PIR before it goes up in flames, up in smoke, charred, ashes, memories, dust etc....
I'm offering to buy it for your own good

 

[JimmyM]

Yikes!
You better sell me your PIR before it goes up in flames, up in smoke, charred, ashes, dust etc....

Gee. Maybe you're right. Thanks for having the best interests of my poor PIR in mind. You're a prince.:sssh:

Seriously, though. The PIR will probably still keeps it's home in my Mag625 when it goes "Lithium Edition".
The '458 will end up in a 3D tri-bored host run on Elite1500s. At that power level it gets hot so quickly that a lot of runtime is useless. I should have bought a couple more HAIII 3Ds with tri-boring.

 

[Icebreak]

Was your HotDriver designed and configured to handle the 65W IRC?

19.3V into a 64458 is massive. It's amazing what some of these lamps I hear about from the 100+ watt club can handle. I'll bet it's very white. Thanks for telling us about it.

 

[JimmyM]

Was your HotDriver designed and configured to handle the 65W IRC?

19.3V into a 64458 is massive. It's amazing what some of these lamps I hear about from the 100+ watt club can handle. I'll bet it's very white. Thanks for telling us about it.

I requested it from Andrew to be set up for the 65W IRC. I've contacted him about it and I'll be sending it in for autopsy. It did make a strange stink though. I definitely let the smoke out. Can't we make these things run on better smelling smoke? :)

It's only rated at something like 1800 lumens. When overdriven at 19.2V it re-rates to 186W and 9300 lumens.

The 54255 is a 24V/250W rated at 9000 lumens. Running on 25 Elite1500s that works out to 1.15v x 25 = 28.75v. At that kind of overdrive it works out to 330W/17000 lm. Good LORD. I'd have to have a 4D tri-bored though.

 

[Icebreak]

Sounds like fun.

 

[cnjl3]

It did make a strange stink though. I definitely let the smoke out.

You fried the FET! I did that on my '138 M*G 100 HD:(
It smelled really bad and i couldnt believe that i went ahead and took another whiff?
I have only run the 25 and 35watt IRC bulbs on my IRC HD because so far its been enough light:)

I do have the 50 and the 65watt IRC bulbs but i guess i am saving them for a rainy day? yeah that sounds good a "cold' wet rainy day to help with the cooling.

 

[cy]

hmm... fried ?

 

[JimmyM]

You fried the FET! I did that on my '138 M*G 100 HD:(
It smelled really bad and i couldnt believe that i went ahead and took another whiff?
I have only run the 25 and 35watt IRC bulbs on my IRC HD because so far its been enough light:)

I do have the 50 and the 65watt IRC bulbs but i guess i am saving them for a rainy day? yeah that sounds good a "cold' wet rainy day to help with the cooling.

Mmm Hmm. Fried.

Try it direct drive. I'm using 4Ah 1/2Ds, they certainly provide the amps. 15 1/2Ds don't pop the IRC 65. What's the worst that can happen?
Well. I suppose the worst thing that could happen is that it blows the bulb and you get glass in your eyes while a piece of white hot filament flies into your fireworks and sweaty dynamite collection.

 

[cnjl3]

I dont have 15 1/2D's but i do have a 15 CBP 2500A size battery pack that should do the trick- I will try my 65watt IRC DirectDrive tonight and see what happens:)

 

[JimmyM]

I dont have 15 1/2D's but i do have a 15 CBP 2500A size battery pack that should do the trick- I will try my 65watt IRC DirectDrive tonight and see what happens:)

That's the way to ring in the New Year! I'm going to try 17 cells as soon as I charge up a pile of them. If that thing will hold 20.2 volts that re-rates to 201 WATTS! Mmmmmm. Cant' wait.

Let me know how it goes.

UPDATE: It held 20.2 volts (briefly) at the pins then sagged quickly to 20.1, 20.0, then the lead wires started to smoke. Those batteries weren't really well charged. My longest charging holder in only 16 cells. I've got to build a longer one now.
Bulb didn't pop. I soooooooo have to build a tri-bore for 18 Elite1500s.

Another update: OK ran 17 1/2Ds fresh off the charger. It was real bright for about 1/2 second then burned out. I'm resting the cells now and will try another fresh '458 in a few hours. Maybe 16 is just about it.
(It was, in fact, 18 cells. Not 17)

 

[LuxLuthor]

As far as I know, AWR never made a reliable hot driver that could handle these 75W-100W bulbs with this kind of surge peak voltage/current spikes....and now he's pretty much vamoosed.

 

[JimmyM]

Yeah. That poor MOSFET just can't holdback that much voltage at the startup current draw. It goes :poof:. Like mine did. It's currently "in the shop".
I'm hoping to have a solution for that, but time is hard to come by.

As far as I know, AWR never made a reliable hot driver that could handle these 75W-100W bulbs with this kind of surge peak voltage/current spikes....and now he's pretty much vamoosed.

 

[LuxLuthor]

Is it hard to make/buy/install a FET that blocks the surge current startup spike to maybe supplement a HD that can't cut the mustard?

 

[JimmyM]

Not necessarily hard, it just takes some time and testing. I've got a design for a softstarting PWM unit. It won't regulate. It will just ramp up duty cycle until a preset point. could be 50-100%, but it won't regulate voltage. It'll just softstart.
So, if your bulb will run on 22 volts if you ease up on it and you have a 22 volt pack, then this is the unit for you. You can limit the duty cycle, so you will end up with a percentage of pack voltage.
Set it to 50% and it will ramp up the duty cycle to 50% then stop. I just need some time to get some parts to fiddle with. My design would be good for 12-40 volts. Perfect for the big incans.

Is it hard to make/buy/install a FET that blocks the surge current startup spike to maybe supplement a HD that can't cut the mustard?

 

[BigusLightus]

JimmyM,

Regarding your first post, what are you fitting your 15 1/2 D cells into? I can only fit 10 into my 6D mag.

Thanks

 

[Icebreak]

Oh now that's verrrrrrry interesting. I ordered some more tuits a while back. When they come in I'll send you a few. They are the round ones, BTW.

 

[LuxLuthor]

Jimmy,

Let me put these in bullets so you can address them easier.

• I understand what you are saying about blocking the spike startup voltage (aka "soft starting"), and that it won't regulate the voltage the way AWR's did...but it sounds like there is a type of "peak regulation" by limiting the % of pack voltage reaching the bulb..but not keeping a set delivered voltage and auto-shutoff like AWR.

• If it essentially puts a cap on max delivered voltage, and that is adjustable, why would you also need the 50-100% feature?

• This would still resolve the entire instaflash issue of the battery voltage being too hot off the charger if my understanding is correct...and if you know the max bulb voltage desired.

• I'm not sure what "duty cycle" means, nor how that applies to to what sounds like a device that puts a cap on the amount of voltage that can EVER be delivered to the bulb from a battery pack.

• Would this "voltage cap" of max delivered bulb voltage be user adjustable with a DMM and rotation type setting that AWR had?

• Another question...how/where would this be installed? (Not sure how large, or if it needs to be below the bulb the way AWR had his HD)

• As the voltage sags with battery use, there is no effect from this since the voltage is remaining below the "max voltage cap" setting, correct?

While this is not an AWR Hot Driver, this is still a really useful and great addition to the community.

Not necessarily hard, it just takes some time and testing. I've got a design for a softstarting PWM unit. It won't regulate. It will just ramp up duty cycle until a preset point. could be 50-100%, but it won't regulate voltage. It'll just softstart.
So, if your bulb will run on 22 volts if you ease up on it and you have a 22 volt pack, then this is the unit for you. You can limit the duty cycle, so you will end up with a percentage of pack voltage.
Set it to 50% and it will ramp up the duty cycle to 50% then stop. I just need some time to get some parts to fiddle with. My design would be good for 12-40 volts. Perfect for the big incans.

 

[JimmyM]

I had bought body extensions. The 17 cell light was 11D long.

JimmyM,

Regarding your first post, what are you fitting your 15 1/2 D cells into? I can only fit 10 into my 6D mag.

Thanks

 

[JimmyM]

• I understand what you are saying about blocking the spike startup voltage (aka "soft starting"), and that it won't regulate the voltage the way AWR's did...but it sounds like there is a type of "peak regulation" by limiting the % of pack voltage reaching the bulb..but not keeping a set delivered voltage and auto-shutoff like AWR.

The PWM-SS is ignorant of voltage. It would only stop increasing duty cycle at a certain point.

• If it essentially puts a cap on max delivered voltage, and that is adjustable, why would you also need the 50-100% feature?

The 50-100% thing IS the adjustability.

• This would still resolve the entire instaflash issue of the battery voltage being too hot off the charger if my understanding is correct...and if you know the max bulb voltage desired.

Sort of... If the pack is 24 volts off the charger and you cap the duty cycle at 90% the bulb will only get 90% Vbat no matter what Vbat is. Initially it will get 21.6V (90% of 24), but as the pack discharges the PWM-SS is still set at 90%. So at Vbat of 20V, the bulb will only get 18V (90% of 20).

• I'm not sure what "duty cycle" means, nor how that applies to to what sounds like a device that puts a cap on the amount of voltage that can EVER be delivered to the bulb from a battery pack.

Duty Cysle is the key to PWM. The PWM-SS turns the MOSFET completely ON or completely OFF many times per second. If it is running at 10kHz, then it switches on and off 10,000 times per second. Every time it turns on, it remains ON for a certain percentage of time between clock pulses. If it remains ON too long between pulses, it just stays ON. That's 100% duty cycle. Since the MOSFET is always ON or OFF, it never acts like a resistor like AWRs. In AWRs case, the MOSFET has to dissipate that additional energy as heat. If it's too much...:poof:

• Would this "voltage cap" of max delivered bulb voltage be user adjustable with a DMM and rotation type setting that AWR had?

Since it doesn't monitor voltage, it can't cap voltage. It will only cap Duty Cycle.

• Another question...how/where would this be installed? (Not sure how large, or if it needs to be below the bulb the way AWR had his HD)

This would be installed in the exact place of AWRs hotdriver. Right under a KIU aluminum socket base.

• As the voltage sags with battery use, there is no effect from this since the voltage is remaining below the "max voltage cap" setting, correct?

No, the output voltage would sag as well. If it would hold voltage, it would be a regulator. There's a design change to allow this, but it's more complicated. I'll start with just the plain PWM softstarter, then look at a regulating version. I must crawl before I can walk. :)