Custom 17mm 5Amp PWM-less linear driver-preliminary

[lagman]

@wight

@lagman

Ok, I’ll do it. I’ll start by explaining Buck, Boost, Linear, Direct Drive. I can always add things later (like Zener diodes, etc.).
I think I’ll do a first part “In a nutshell” and below that a more detailed version with graphs and things for people that want to understand how it really works. I’ll also insist on efficiency.
I only have two 7135 based drivers (I have 2 flashlights, I’m a noob! ) so I’ll have to buy a buck and boost driver if I want to plot some graphs. That will take time.
When led4power releases his driver I’ll try to include it. Unfortunately I didn’t win at the giveaway so that’ll have to wait.
I worked on a high end Buck driver used in Smartphones for 6 months as an intern, so I should be able to give some accurate infos, but I WILL make mistakes so you’ll have to check what I say.

Sounds good. Please PM me so that I don’t miss the thread.

I took my time but here it is! Fell free to make critical comments as this is supposed to be clear for newbies.

Understanding the difference between Linear, Buck, Boost and Direct Drive drivers

A long time ago I promised I would do a topic to explain to the interested layman the difference between Linear, Buck, Boost and Direct Drive drivers. Well, here it is. Direct Drive [image] This is the simplest and cheapest design. As its name implies, it is a direct path to the LED, just like old incandescent flashlights. Sometimes there is a control chip and transistor to create modes (High, Low, Strobe, etc.) by rapidly switching ON and OFF the LED. That’s called PWM. This is used by peop…