Drivers for 445

siqueirah said:

I have a question:
Would these AMC7135 work with ONE 18650 (3.7v) cell ?
What driver would be the most suitable, if I wanted something arround 700mA from just ONE 18650 cell ?

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I'm definitely no expert with electronics, but that's what I was planning to do with the 1400mA version. If your budget allows for it, something like Dr. Lava's Flexdrive or the MicroBoost drive would probably be better.

siqueirah said:

Complementing my previous question: Is it possible to make myself a driver that can give me arround 700mA with a single 18650 cell ?

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It would have to boost the voltage up. Sure it's possible, but it is also difficult to do.

siqueirah said:

Complementing my previous question: Is it possible to make myself a driver that can give me arround 700mA with a single 18650 cell ?

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Why not just buy yourself a Microflex for $26 shipped and be done with it?

I'm using the amc7135 driver in a couple 445 builds.

The 1400ma version has 4 chips on them, each chip will provide 350ma , remove 1 and you now have the driver at 1050ma.

To power the diode you will need more than what a single li-ion batt can provide. Using 2 li-ions the drivers provides full power but it gets very hot. I have thermal epoxied a ram heatsink to the driver to help alleviate that.

Just fyi, you don't have to order the 20-packs to get amc chips, here's a 1050mA version single: DealExtreme: $2.36 2.7V~6V 3W Cree Circuit Board for Flashlights (15mm*2.7mm)

Hmm, do you think this single AMC + 2xCR123A would to the job ?
Also, 2 CR123A fit where one 18650 fits, right ?
Isn't 1050mA too much current ?

siqueirah said:

Hmm, do you think this single AMC + 2xCR123A would to the job ?
Also, 2 CR123A fit where one 18650 fits, right ?
Isn't 1050mA too much current ?

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Yes that would work.

Another user finally damaged a 445nm diode by running it @ 2.6A. , His thoughts are that 1.8A is the safest to run the diode at , max.

1.050mA /1A should be safe in my opinion. I am currently running one @ 1400mA. without issue.

Ah, great. Do you think the 1050mA would get too hot ?
Do you know any spacer for me to charge the CR123 in a 18650 charger?

siqueirah said:

Do you know any spacer for me to charge the CR123 in a 18650 charger?

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Any rare earth magnet will work. You can even simply use a small bolt, screw, nail, rod, etc. but they don't "hang on" like the magnet does.

Peace,
dave

siqueirah said:

Ah, great. Do you think the 1050mA would get too hot ?
Do you know any spacer for me to charge the CR123 in a 18650 charger?

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It does get hot . There might be a way to reduce the voltage that is given to the driver by way of a resistor and help reduce the heat as well as passive cooling.

Spacer.. hmm.. .a piece of metal?

What would happen if I set a Flexdrive to its max of 1.5A and run it? Would it have a really unstable output, as Exerd said, or would it die? Also, I thought these diodes needed like 5V input. I was thinking about using a 18650, but that would only give 3.7V to the diode with these AMC7135 drivers. Would putting 2 18650s in series and feeding the driver 7.4V fry the driver, or how how would it get?

Lumify said:

What would happen if I set a Flexdrive to its max of 1.5A and run it? Would it have a really unstable output, as Exerd said, or would it die?

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I've never actually had a Flexdrive go "unstable". I merely stated that when some of us were pushing 405nm diodes, that it was under discussion whether or not the Flexdrive would be up to the currents. The Microboost was talked about as the possible successor to the Microflex, which is why I had a feeling Microboost>Microflex in the event of maximum current.

I have used a Microflex to power an 808nm diode at 1.2A, but that is only 2.2V, so that is also only 2.64 watts. A 4.5V diode at 1A is of course, 4.5 watts. I have run a Flexdrive at 5.9V/605mA without issue, which is still only 3.6 watts.

The 445nm diode will surely test these drivers. Hopefully the Microboost I ordered will show up tomorrow so I can compare it to a Flex. I have a feeling both are going to fall far short, if we had someone push this diode to 2.6A! That is way higher than I had expected. If this diode is safe at 1.4-1.6A, we need to seriously be looking for the best driver to put it right there.

On the other hand, these AMC7135 drivers state 2.7-6V. So why again is more voltage than a single 3.7V Li-ion needed? Is it getting too hot trying to boost the voltage to 4.5V on a single cell?

Lumify said:

What would happen if I set a Flexdrive to its max of 1.5A and run it? Would it have a really unstable output, as Exerd said, or would it die? Also, I thought these diodes needed like 5V input. I was thinking about using a 18650, but that would only give 3.7V to the diode with these AMC7135 drivers. Would putting 2 18650s in series and feeding the driver 7.4V fry the driver, or how how would it get?

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Two fully charged 18650's would give you 8.4V.

The flexdrive can only take an input voltage of 2.5V-5.5V. Above that will fry the driver.

Peace,
dave

Hmm, great. I'll use this AMC with one of these heatsinks
DealExtreme: $2.65 Aluminum Cooler Heat Sink Chipset for RAM Memory - W Type (8-Piece Set)

About the resistor to drop the voltage down, if I use 2xCR123A ( 7.4~8.2v) which resistor should I use ?

Here we go guys.

->SOB converter<-

Driver which is 0.55" diameter.

3-16V

1.5A max current. Designed for driving a 5W LED.

With resistors soldered on, $17.75.

I'm thinking two RCR123s in series for 8.4V charged sounds good to me.

Edit: The configuration to achieve 1.5A is kind of hard to do. You could use a 0.03ohm single resistor which would deliver a maximum of 1.67 amps. Or, two 0.06 ohm resistors could be used for a parallel of 0.03 ohm. Still within ~10% of max current rating.

SpyderFire said:

Yes that would work.

Another user finally damaged a 445nm diode by running it @ 2.6A. , His thoughts are that 1.8A is the safest to run the diode at , max.

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What the fuck

How long duty cycles did he run it at? And how long are you running your 1400mA?