How to build a linear LED driver that is dimmable?

[EasyB]

It sounds like continuously adjusting the gate voltage of a MOSFET would get you what you want. I’ve done this a couple times using a voltage divider and an adjustable resistor, and it works well. It is very simple to DIY as far as circuitry.

mod: continuous brightness adjustment via sliding switch

I have been more interested in optimizing the user interfaces of my flashlights. Ramping FW like Narsil and from Toykeeper have the features I want and are intuitive to use. Maybe an even more intuitive UI is a sliding switch controlling the brightness from off to full. The way I chose to implement this was to continuously vary the gate voltage to a MOSFET via a voltage divider with a sliding variable resistor. The light I put it on is my 7xXPL modded Convoy L2. I had previously drilled a small…

Mod: Convoy S2 with rotary tail switch

This mod combines aspects of two of my recent mods, the e-switch in the tailcap mod and the sliding resistor switch mod. It uses a voltage divider with an adjustable resistor to continuously control the gate voltage to a MOSFET. In the tailcap, the MOSFET needs a separate power source to turn on. In my tail e-switch mod I used a Li ion coin cell. I would prefer to use a supercapacitor instead of a coin cell, but the attiny13A MCU requires 2mA while on, which is too much for a supercapacitor of …

If you want a more traditional clicky switch the LD-3 driver from led4power is a linear driver with no-PWM modes.

Or there are triple channel drivers like the texas avenger. You could put a different number of 7135 chips on each channel. This would only actually give you 3 pure linear without PWM modes, though.