gcbryan
Flashlight Enthusiast
In a (1) 18650 led flashlight (let's say XR-E) how does a constant current driver work? Or rather how would one work that drops out of regulation just a bit before the protected battery circuit cuts out so that you have a brief period of non regulation and gradual dimming rather than an abrupt cutoff?
Most protected 18650 batteries cutoff at 2.75 V. Using a Cree XR-E as an example what is the minimum voltage needed to light it up. Will it still power the led right up to the 2.75 V cutoff? I guess this is where a boost driver comes into the picture?
So, in this scenario I guess we're talking about buck and boost drivers being needed and a constant current circuit is still an additional function to all that right?
What are the efficiencies of the various types of drivers using this setup (a single 18650 and a XR-E)? I guess the types are buck, boost, buck/boost and is constant current a special form of all of those? There's also linear drivers.
Is there a sticky already made somewhere with all this explained?
Most protected 18650 batteries cutoff at 2.75 V. Using a Cree XR-E as an example what is the minimum voltage needed to light it up. Will it still power the led right up to the 2.75 V cutoff? I guess this is where a boost driver comes into the picture?
So, in this scenario I guess we're talking about buck and boost drivers being needed and a constant current circuit is still an additional function to all that right?
What are the efficiencies of the various types of drivers using this setup (a single 18650 and a XR-E)? I guess the types are buck, boost, buck/boost and is constant current a special form of all of those? There's also linear drivers.
Is there a sticky already made somewhere with all this explained?
Last edited:
