Comparing two 2400mah drivers, which one best?

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TSellers
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Comparing two 2400mah drivers, which one best?

I’ve noticed a driver I had previously overlooked on Fasttech’s site, 1* Lithium 5-Mode 2.4A LED Flashlight Driver. It would seem to be similar to the Nanjg 7*7135 driver, but without the ability to select a mode.

As it appears to just have one integrated regulator, I was wondering if there would be any advantage to it over the Nanjg? Not being a fan of the SOS mode there would have to be some clear cut advantage to using it such as greater efficiency perhaps?

Regards, TS

Slim Pickens
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In short you’ll probably best served by the 7*AMC7135 driver.

The Nanjg uses linear regulators for (surprise) regulated output Party
Whereas the other driver will not regulate output.

TSellers
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Thanks for that. So if it’s not regulated, would it be direct drive then?

Regards, TS

Slim Pickens
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Yes, it would exhibit direct-drive-like decaying output.

ohaya
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Slim Pickens wrote:
Yes, it would exhibit direct-drive-like decaying output.

Hi,

Sorry to drop in, but I was wondering: If this is a direct drive driver, why would it be limited to 2.4 amps? Shouldn’t the output be dependent on the current that the battery is able to supply?

Slim Pickens
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ohaya wrote:
Slim Pickens wrote:
Yes, it would exhibit direct-drive-like decaying output.

Hi,

Sorry to drop in, but I was wondering: If this is a direct drive driver, why would it be limited to 2.4 amps? Shouldn’t the output be dependent on the current that the battery is able to supply?


You make a great point, and yes, if it was truly ‘direct drive’ the current delivered to the emitter could be disastrously high (thermal runaway—>poof). Since the input voltage directly influences emitter current I describe these types of drivers (FET, PWM’d modes) as direct-drive-like.
TSellers
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I’m also trying to get my head around the direct drive algorithm.

Regards, TS

ohaya
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Slim Pickens wrote:
ohaya wrote:
Slim Pickens wrote:
Yes, it would exhibit direct-drive-like decaying output.

Hi,

Sorry to drop in, but I was wondering: If this is a direct drive driver, why would it be limited to 2.4 amps? Shouldn’t the output be dependent on the current that the battery is able to supply?


You make a great point, and yes, if it were truly ‘direct drive’ the current delivered to the emitter could be disastrously high (thermal runaway—>poof). Since the input voltage directly influences emitter current I describe these types of drivers (FET, PWM’d modes) as direct-drive-like.

Ok, thanks. I had noted the “-like” in your post, but wasn’t quite sure how to ask if you were differentiating between “direct drive” and “direct-drive-like”.

So, if I’m understanding, the way that this driver would be characterized is:

- Output current to emitter decreases as input voltage decreases, and
- Output current is limited to 2.4 amps

or something like that?

PilotPTK
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ohaya wrote:
Slim Pickens wrote:
ohaya wrote:
Slim Pickens wrote:
Yes, it would exhibit direct-drive-like decaying output.

Hi,

Sorry to drop in, but I was wondering: If this is a direct drive driver, why would it be limited to 2.4 amps? Shouldn’t the output be dependent on the current that the battery is able to supply?


You make a great point, and yes, if it were truly ‘direct drive’ the current delivered to the emitter could be disastrously high (thermal runaway—>poof). Since the input voltage directly influences emitter current I describe these types of drivers (FET, PWM’d modes) as direct-drive-like.

Ok, thanks. I had noted the “-like” in your post, but wasn’t quite sure how to ask if you were differentiating between “direct drive” and “direct-drive-like”.

So, if I’m understanding, the way that this driver would be characterized is:

- Output current to emitter decreases as input voltage decreases, and
- Output current is limited to 2.4 amps

or something like that?

That driver has no current limit. It’s about as direct drive as you get. The only thing that will limit current is battery voltage, spring/wire resistance and the RDSon of the mosfet.

PPtk

I am currently extremely busy with work. Please do not expect a response from me quickly. I will be dropping in as time permits, but the amount of time I can dedicate to responding to topics and PMs is very limited.

Slim Pickens
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ohaya wrote:
Ok, thanks.

So, if I’m understanding, the way that this driver would be characterized is:

- Output current to emitter decreases as input voltage decreases

Indubitably
ohaya wrote:
- Output current is limited to 2.4 amps
If their specs are to be trusted it will be in the neighborhood of 2.4A. FT is traditionally better at actually testing their drivers than other budget vendors, but they’re still not infallible.
Edit: Exactly what PPTk said. Current draw from a fresh cell will vary between hosts, so YMWV.
ohaya wrote:
or something like that?
Yes a healthy dose of ambiguity xD