When is FET enabled?

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Frostcream
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When is FET enabled?

In Anduril 1 and 2, at what part of the ramp is FET enabled? I have never seen this mentioned, and am extremely curious.

Does anyone know? Well, of course someone knows.. Smile

Sunnysunsun
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Depends on the light. Stock Lume1 variants have fet only at step 150/150; everything up to and including step 149 is just constant current. Fet+7+1 drivers have fet at a later step than fet+1 drivers since the 7 extra 7135 chips allow for a higher brightness without resorting to fet.

Some lights like the GT70 are fet only. (As far as I know)

Frostcream
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It seems I should clarify. I’m specifically concerned with the 9amp+ FET DT8 driver. I wonder where one goes for info without bothering Toykeeper?

Sunnysunsun
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https://bazaar.launchpad.net/~toykeeper/flashlight-firmware/anduril2/vie...

Look at line 31. Count the number of non zero numbers and subtract that number from 150 to determine what level the fet pwm begins.

It should be around step 120 but I’m not certain what level it is exactly.

starryalley
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Sunnysunsun wrote:
https://bazaar.launchpad.net/~toykeeper/flashlight-firmware/anduril2/vie...

Look at line 31. Count the number of non zero numbers and subtract that number from 150 to determine what level the fet pwm begins.

It should be around step 120 but I’m not certain what level it is exactly.

I have a question regarding FET in Anduril specifically about turbo.
Looking at this config file, the turbo level (level 150) has PWM1 set to 0 and PWM2 set to the highest value. But for 219b’s config, the turbo level has PWM1 set to highest value. What’s the difference?

Sunnysunsun
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At 100% fet, you don’t want the constant current (pwm1) part on at all since it limits the output.

The 219b version never goes 100% fet, only around 50% iirc. It alternates between the constant current and fet channels at step 150.

Regular configurations alternate between the constant current and fet channels all the way up to step 149.

starryalley
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Sunnysunsun wrote:
At 100% fet, you don’t want the constant current (pwm1) part on at all since it limits the output.

The 219b version never goes 100% fet, only around 50% iirc. It alternates between the constant current and fet channels at step 150.

Regular configurations alternate between the constant current and fet channels all the way up to step 149.

Thanks for the reply. That makes sense. However what do you mean by “alternates between CC and FET channels”? How does it work when both FET and constant current circuit work together or alternate between them? For example, at turbo level in 219b constant current (9A) is at 100% and FET at 50%. What will be the current sent to the emitters assuming the battery is max 20A?

Frostcream
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Sunnysunsun wrote:
https://bazaar.launchpad.net/~toykeeper/flashlight-firmware/anduril2/vie...

Look at line 31. Count the number of non zero numbers and subtract that number from 150 to determine what level the fet pwm begins.

It should be around step 120 but I’m not certain what level it is exactly.

It is 120.

Thank you!

So in my red-blue-green W1 DT8 mix the green and blue emitters only fire up when FET’s engaged.

This is my angriest hot-rod now. I have nothing that gets hotter faster, including my X80GT. It is bright and hot af even on a low cell charge. Kind of a crazy little beast.

stephenk
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Some useful info in this thread. What is the “stop panicking” stuff in the Anduril 2 code?

Sunnysunsun
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starryalley wrote:
Sunnysunsun wrote:
At 100% fet, you don’t want the constant current (pwm1) part on at all since it limits the output.

The 219b version never goes 100% fet, only around 50% iirc. It alternates between the constant current and fet channels at step 150.

Regular configurations alternate between the constant current and fet channels all the way up to step 149.

Thanks for the reply. That makes sense. However what do you mean by “alternates between CC and FET channels”? How does it work when both FET and constant current circuit work together or alternate between them? For example, at turbo level in 219b constant current (9A) is at 100% and FET at 50%. What will be the current sent to the emitters assuming the battery is max 20A?

A 20A battery tells us nothing since emitters have different forward voltages.

Assuming an ideal circuit and full fet is 20A with a 50% duty and the constant current part is 5A,

Fet will be on 50% of the time so effectively 10A from fet. The constant current is on 100% of the time, but 50% of that time it’s not effective since the fet is on and a battery cannot push any more current, so 2.5A from the CC part.

Thus the light is effectively operating at 12.5A

Of course there are little losses and gains here there but you’ll see about 12.5A

Sunnysunsun
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stephenk wrote:
Some useful info in this thread. What is the “stop panicking” stuff in the Anduril 2 code?

Thermal throttle drops the output to try to prevent the light from getting any hotter. Stop panicking is a level where anduril no longer continues dropping the output since it should be a (low enough, often 1×7135) sustainable output.

mattlward
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Electronics aside, one would need to review the exact source code for a given light to determine where the FET is enabled and at what PWM level it is modulated. I have multiple versions of Anduril compiled for differing levels of max output depending on the heat path and target LED and number of target LEDs that my build will have.

EDC rotation:
FW1A, LH351D 4000k (second favorite)
FW3A, LH351D 3500k
FW3A, SST20 FD2 4000k
FW3A, Nichia 4000k sw40 r9080 (favorite light!)
FW3A, Cree XP-L Hi 5A3
Emisar D4V2, SST20 4000k
S2+, XM-L2 T6 4C

stephenk
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Sunnysunsun wrote:
stephenk wrote:
Some useful info in this thread. What is the “stop panicking” stuff in the Anduril 2 code?

Thermal throttle drops the output to try to prevent the light from getting any hotter. Stop panicking is a level where anduril no longer continues dropping the output since it should be a (low enough, often 1×7135) sustainable output.


Thanks for the info!
starryalley
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Sunnysunsun wrote:

A 20A battery tells us nothing since emitters have different forward voltages.

Assuming an ideal circuit and full fet is 20A with a 50% duty and the constant current part is 5A,

Fet will be on 50% of the time so effectively 10A from fet. The constant current is on 100% of the time, but 50% of that time it’s not effective since the fet is on and a battery cannot push any more current, so 2.5A from the CC part.

Thus the light is effectively operating at 12.5A

Of course there are little losses and gains here there but you’ll see about 12.5A

Thank you for the details! Appreciated it.