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I like Monkeys
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Discussion Starter · #1 ·
Anybody used the DX 3256 drivers at 7.4 volts? Although it is rated to 9V I've seen a couple of reviews in the DX site say it is less reliable, others say it is fine. Both seem to get about 1000mA from the driver at 7.4v. I may change the resistor to get it down to 800mA to keep it a little cooler. I'm planning on running a 3256 with the 4000mAh/19.95 LiOn pack from batteryspace.
 

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I like Monkeys
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Discussion Starter · #4 ·
NEstinkyrider said:
isn't this driver supposed to be regulated at 800ma output as is?
Yes but that is at 6V IIRC. The graph's I've seen show it running at about 1000ma with 7.4 volts. Which is good for me if I can keep the LEDs cool with my modified achesalot design.
 

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I like Monkeys
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Discussion Starter · #5 ·
msxtr said:
Hi, I it use in the majory of my DIY lights and work perfectly with 7,4 volts battery of Li-Ion

Greetings - Saludos

msxtr
Great! I'm waiting on my batteries to finish up my lights. Hopefully I can be riding with 600 lumens of fun in a week or two.
 

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I use these drivers with exactly the same battery you are looking at and some of the drivers work fine, some do not. Make sure you check to see that they are only putting out 1000 ma when the battery is fully charged... after the battery drops a little in voltage it is not an issue but not ideal because it is nice to take the battery off the charger and use it...

I have used probably 30-40 of these drivers in various lights... and about 1 out of 4 will put out 1200-1400+ mah on a fully charged 7.2v Li battery (they then drop to around 1000-1100 ma when battery voltage drops) Just make sure you test each one with a fully charged battery and select ones that only put out 1000 mah on the charged battery (they drop to 800-900 when the battery voltage drops)
 

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I like Monkeys
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Discussion Starter · #7 ·
tamen00 said:
I use these drivers with exactly the same battery you are looking at and some of the drivers work fine, some do not. Make sure you check to see that they are only putting out 1000 ma when the battery is fully charged... after the battery drops a little in voltage it is not an issue but not ideal because it is nice to take the battery off the charger and use it...

I have used probably 30-40 of these drivers in various lights... and about 1 out of 4 will put out 1200-1400+ mah on a fully charged 7.2v Li battery (they then drop to around 1000-1100 ma when battery voltage drops) Just make sure you test each one with a fully charged battery and select ones that only put out 1000 mah on the charged battery (they drop to 800-900 when the battery voltage drops)
Thanks for the tip, I noticed on the DX questions that one guy mentioned scraping a resistor to drop the current. I may check the drivers that I have and any putting out too much I'll trim, or see if I can get a few resistors to play with the current output. I'd ideally like to run at about 800 ma to keep the heat down.
 

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I like Monkeys
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Discussion Starter · #10 ·
super-fast said:
I got 4 boards and they were all smoke creators. They worked fine for a few minutes, but they became way to hot till the transistor starts melting... Maybe I had bad luck.
I've had 100% success with 4 boards and 4.8 - 6V. My current light is a dual copper pipe with 4.8V pack running 3256 & SSC P4's. Been flawless for over a year. Sounds like you had something hooked up wrong.
 

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No I am sure I had hooked up everything right. What can you do wrong with such a simple driver? Just connect de '+' in the middle and at the side the '-' connection and you're ready to go. The wires to the led come pre-soldered and they were at the right place attached.
I forgot to mention I used a 7.4V li-ion fresh from the charger, so at 8.4V. The leds were Cree XR-E Q5 and R2's.
 

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yeppers.... that is exactly the same thing that happened with a few of my drivers and a couple of leds when you use a freshly charged 7.2 v li battery... when you do find the drivers that work, they have been awesome... not one failure in many lights I have built... if they make it the first coupl of times you use them!!!
 

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Spanish biker
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tamen00 said:
I use these drivers with exactly the same battery you are looking at and some of the drivers work fine, some do not. Make sure you check to see that they are only putting out 1000 ma when the battery is fully charged... after the battery drops a little in voltage it is not an issue but not ideal because it is nice to take the battery off the charger and use it...

I have used probably 30-40 of these drivers in various lights... and about 1 out of 4 will put out 1200-1400+ mah on a fully charged 7.2v Li battery (they then drop to around 1000-1100 ma when battery voltage drops) Just make sure you test each one with a fully charged battery and select ones that only put out 1000 mah on the charged battery (they drop to 800-900 when the battery voltage drops)
:eek::eek::eek::eek::eek::eek: 30 or 40???? :eekster::eekster::eekster::eekster::eekster: and I that thought that had did very much lights....:cryin::cryin: hehehe:smilewinkgrin:

Greetings - Saludos

msxtr
 

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Lets RIDE!
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What's the procedure for testing these drivers? Meter parallel with the led? Or are you using a resistor in place of the led?

Are you guys running one driver per led? I'm working (slowly :rolleyes: ) on a 2 x Q5 helmet light; I was planing on two drivers, parallel, on a 4.8v (4xAA NiMH) battery pack.

JZ
 

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Spanish biker
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JimZinVT said:
What's the procedure for testing these drivers? Meter parallel with the led? Or are you using a resistor in place of the led?

Are you guys running one driver per led? I'm working (slowly :rolleyes: ) on a 2 x Q5 helmet light; I was planing on two drivers, parallel, on a 4.8v (4xAA NiMH) battery pack.

JZ
Hi, You can use of several forms. I use this driver in series with 2 leds 7,4v battery Li-Ion, without resistors. If you want use 4,8 volts only, then you will have to use 1 driver for led.

Greetings - Saludos

msxtr
 

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msxtr said:
Hi, You can use of several forms. I use this driver in series with 2 leds 7,4v battery Li-Ion, without resistors. If you want use 4,8 volts only, then you will have to use 1 driver for led.

Greetings - Saludos

msxtr
Hey msxtr
If I am not mistaken, I remember that you posted somewhere a cheap ebay source for 7,4 batteries for digital cameras. Can you repost the link?
Many Thanks!!
 

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I have tested this driver, DX3256, with two different batteries and got some weird results.

In both cases I tested the current drawn from the battery using two SSC P4 leds (one driver for each led)

First battery, 6v
Output current 1100mA

Second battery, 4.8v
Output current: 600mA

Whats the reason for this reading? Do I have defective drivers or do I miss something obvious?
thanks!!
fab
 

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I'm looking to do a similar configuration as Ausable.

Namely 2 x DX3256 in parallel, with each driver wired to a Cree XR-E (one driver for each LED). Battery would be 1 x 7.4 Li-On.

I'd like to limit the current to either 800Ma or 1000Ma. While the driver is supposed to be maxed at 800Ma, this thread makes light of the driver's flaws.

To limit the current at:

800Ma - which resistor to use?
1000Ma - which resistor to use?

If anyone has a better suggestion or an answer to my question, thanks in advance!

Ausable said:
I have tested this driver, DX3256, with two different batteries and got some weird results.

In both cases I tested the current drawn from the battery using two SSC P4 leds (one driver for each led)

First battery, 6v
Output current 1100mA

Second battery, 4.8v
Output current: 600mA

Whats the reason for this reading? Do I have defective drivers or do I miss something obvious?
thanks!!
fab
 
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