LED questions

[rescue15]

I have the skills to fabricate it but don't have the knowledge to formulate the parts list. Can some one post a parts list for the light head using 3 to 5 CREE XRE leds?
I need emitters, heat sinks, voltage regulators etc.

Also, are there any benefits to use the CREE XRE vs the SSCP7?

Does anyone know of any pre wired inserts using these components already mounted in a reflector? Would there be anyone out there willing to make a light head using these components and a Mag Light for a reasonable cost?

Thanks in advance for any help.

Steve

 

[wwunder]

Hi,

I just made a mag conversion with this single ssc p7 from dealextreme. It seems pretty bright, but a little floody. Its just finished so I have to dive test it still. You should search for the mods made by Packhorse on this forum and candlepowerforums... I think he is selling some stuff too.

another interesting premade led dropin from dealexteme here

 

[rescue15]

Anybody else? I have seen several good threads but if someone can post more detail...sku numbers of what they used at DX...it would be helpful. The DX site has very poor descriptions of their products and it is very confusing for someone with little electronics experience.

Thanks,
Steve

 

[Packhorse]

Best you check out CPF and the DIY forums at SODS

The P7 is a great LED but due to its size its hard to get a tight focus. DX has a P7 reflector, driver and heat sink set up that is easy to use although I think the heat sink is a little small for the job.

The single die Cree's are my pick. Get as many as you can and cram them into a light head using aspheric lenses. 4 will out shine a 21watt HID and fit in a mag light head @ 48mm. Build a 54mm head and you will get 7 in there and be close to a 35watt HID.
There are plenty of good drivers out there but I have only used the KaiDomain P7 driver. ( works for any LED set up at 2.8 amps) I use it on my 4 Q5 aspheric set up.

I suggest you have a good think about all aspects of the light before you start.
How much run time do you want?
What sort of beam do you want?
How bright do you want it?
How big do you want it?
What batteries will you use?
How many modes do you want?
How will it be switched?

Only when you have answered these questions should you start buying stuff, other wise you will have a whole bunch of parts left over that you will have to buy even more parts to use. Im speaking from experience here!

 

[rescue15]

Packhorse, Thanks! That is the kind of info I am looking for.

This is what I am thinking.
1. at least as bright as a 50 Watt Halogen lamp
2. I want a tight piercing beam
3. 3 to 4 hours run time (is this possible?)
4. 1 mode and use a latching reed switch
5. c cell NiMh 12 v 4.5 aH battery
I would like the canister as small as poss 2.5"pvc pipe less than 1 ft long

Are these parameters possible? You know what DX has. Using the CREE LED's, what would your recommendations be to attain my goals? I am thinking 4 or 5 led's in their reflector inserted into a D cell MAG light.

Thanks,

Steve

 

[bronk]

Take a look at the photos for my LED can light. I got the 3 CREE LEDs, polished triple reflector, and silicone grease from Deal Extreme. Very nice tight spot.
For a current regulator see: A linear Constant Current LED Lamp Dimmer. Simple circuit with very low drop out voltage and will run even on low voltage.
You need to regulate current NOT voltage. The 3 LEDs in series will run about a 10.5 v drop (varies from 3.4 to 3.7 v per led depending on current and temp). This means that something really simple like a LM317 will NOT work with a 12v supply. A LM317 will need a minimum 3.2-3.5 v drop (2-2.2v internal and 1.2v for current sense resistor).
The lamp dimmer components are not critical I used a IRF630 mosfet, 2n5088 and 1N4148s in mine as that was what was in my parts bin.
The battery is a 12v 4.5AH NIMH pack from BatterySpace. I did not want to fool with Li-ion and TSA baggage restrictions. With 950mA drain a 4.5 AH pack should give 4-5 hours. I set mine up with a 125mA low setting (just added a 10 ohn resistor) so that it won't burn out photos. This should last a LONG time on low power.

 

[rescue15]

Hey Bronk, I like your light head. How did you make it?
What battery pack did you use?

Steve

 

[Packhorse]

Packhorse, Thanks! That is the kind of info I am looking for.

This is what I am thinking.
1. at least as bright as a 50 Watt Halogen lamp
2. I want a tight piercing beam
3. 3 to 4 hours run time (is this possible?)
4. 1 mode and use a latching reed switch
5. c cell NiMh 12 v 4.5 aH battery
I would like the canister as small as poss 2.5"pvc pipe less than 1 ft long

Are these parameters possible? You know what DX has. Using the CREE LED's, what would your recommendations be to attain my goals? I am thinking 4 or 5 led's in their reflector inserted into a D cell MAG light.

Thanks,

Steve

1. Yes you can get as bright as a 50watt halogen
2. Best way to get a tight beam is using aspheric lenses
3. 3- 4 hour run time is possible. Any run time is possible. But not on a 12v 4.5ah battery pack. You will need about 20watts of LED power to get close to 50watt halogen output. 20wattx5 hours = 100 watt hours. a 12V 4.5 ah pack gives you 54 watt hours. And we have not talked about electronics and battery inefficencys.
4. latching reed switch? I assume you mean a latching circuit controlled by a reED? Probably easier to just use a reed activated relay so when the switch is on the light is on. when switch is off so is light.
5. that battery pack will fit in a cannister way smaller than that.


Most of what you want I have accomplished as can be seen here except the run time. If you use the highest capacity NiMh D cells (10ah or 12 ah) ( Id use 8 of them at 9.6v) you should get close to 4 hours at full output. If you run the LEDs at 700ma instead of 1400ma like I did you will get 8 hours. Use a different driver and run them at 1000ma and get 6 hours.



P7 mag light vs 4x Q5 aspheric vs 50 watt halogen.

Solus 1250 vs 21watt HID vs 4 x Q5 Aspheric

 

[rescue15]

What's up with the DX website? I haven't been able to get onto it in 2 days.

 

[bronk]

The lighthead was turned from 2.5" diameter 6061 aluminum rod. I have a 110yr old Rockford metal lathe . The turning took nearly a day (I am not really a good machinist either). I bored out the center to the diameter of the trimmed down reflector and parted off the ring for the front. Then I bored out the rest of the center with slip clearance for the heatsink and reflector. The goove for the o-ring was probably the touchiest part. The oring is a plumbing part from Ace. The lens is 1/4" acrylic.

I put the regulator assembly in the battery case. It was built on perf board and a chunk of aluminum for the heat sink. It would be a bit tricky to fit one in the head. The battery is a 12v 4.5AH NIMH pack form BatterySpace. I use the same charger for that and the pack for my wife's Light Cannon (also bought from BatterySpace part# BL-H12V4500W5.