Is an AA/14500 driver linear when running on 14500s?

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merlot
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Is an AA/14500 driver linear when running on 14500s?

The driver in something like a Convoy T3 drives a 3V emitter from both 1.5V AAs and 3.7V 14500 batteries. Clearly its running as a boost driver when using AA batteries, but what topology would it be considered when using 14500s? Is it simply burning off the excess voltage as a linear driver would?

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SammysHP
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Depends on the driver. Everything is possible. Some less expensive might run linear or direct drive with PWM, some switch into buck mode and some even use boost-buck.

thefreeman
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Well it depends.
Some I’ve tested like Acebeam H40 and Zebralight H/SC52 are linear, in others the boost converter is in passthrough mode or bypassed and dimmed with PWM (”FET”) like Sofirn SP10S an Manker E02/3 II.
I have not seen any with buck-boost topology, if it exists it would likely be very limited in power.

Edit : I seem to recall seeing an AA/14500 Convoy driver with two inductors, implying a boost and a buck converter, but I can’t find it in the Convoy store.

merlot
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This is the 12 mode Convoy T3 driver, it does have two inductors doesn’t it? Does that mean its a buck/boost?

Link here

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g_damian
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BlueSwordM wrote:
@g_damian, the T3/T4 are using 92% efficient buck boost drivers.

Source: https://budgetlightforum.com/comment/1875689#comment-1875689

merlot
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g_damian wrote:
BlueSwordM wrote:
@g_damian, the T3/T4 are using 92% efficient buck boost drivers.

Source: https://budgetlightforum.com/comment/1875689#comment-1875689


Thanks

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buck91
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I really like those Convoy 12 mode omnivore drivers… Should probably pick up some extras while they are available… I just wish they ran brighter on li-ion. Not much/any difference going between NIMH/Li-ion/Primary to my eyes.

thefreeman
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merlot wrote:
This is the 12 mode Convoy T3 driver, it does have two inductors doesn’t it? Does that mean its a buck/boost? https://ae01.alicdn.com/kf/H614a8a5c2c894a9d8371d2f7f1587b59R.jpg_640×6...

Link here

Thanks for the link, I was tempted to buy one to analyse it but it’s quite expensive compared to the usual Convoy driver offering.
But yeah, could be boost or buck depending on input voltage, or cascaded boost+buck like one driver I designed.