I also have some of these Zener Diodes . I’m assuming they are the same thing but in a different format. How would I tell one end from the other, and can the Zener diode be attached in other places? Obviously this type has reach and could span a large area.
The datasheet shows that they have a line. The part can be oriented based on the line, same as your other zener diodes. The datasheet also shows a Fairchild “F” logo which will be right side up when you have the line on your left.
I’m assuming that the capacitor is the only place to attach a Zener. I’m not really sure what a capacitor does though. Is its sole function to control the voltage going to the MCU?
That is not the purpose of the capacitor. Here is the Simple English Wikipedia entry for a Capacitor. Hopefully someone has a better link to help explain what capacitors do. Due to their properties capacitors get used in many ways, some of them are harder to grasp than others. This one is used to help ensure clean power for the MCU – it smooths out dirty power.
The Zener diode must go from after 200 Ohm resistor (or whatever value, you may sometimes be advised to use a different value) to GND. It must have the orientation described – “The line should be facing away from the out-side ground ring of the driver.” Look at comfychair’s annotations below. You may not install the zener on +Vin or LED+, but you may install it after you pass the D1 marking. The bottom of R1, the Vcc pin on the MCU, or the bottom of D1 are all acceptable. From any of those to GND.
hey I have seen that pic somewhere before.
He was the first here that I know of that was doing the Zener mod and I learned from him, by asking a thousand stupid questions. Not long after that, it got pretty popular.
not to get too far off topic - but my modded convoy arrived yesterday…. its…… wonderful 
That’s a great diagram, and I totally get it. If I can get a clear visual, I can usually grasp things better.
I had asked Comfy many questions and successfully completed the build, took pictures and shared them here on Aug 1, 2013. So yeah, this has been done here for around a year. A few others had experimented with it before for bicycle lights and such if I remember correctly, but it was new to flashlights this time last year. That’s about the time that Richard joined the forum and gasoline de-doming was catching on from Germany and such.
Also from a long time ago. Relatively
Is the Vcc the same as the 8 pin on the MCU?
Yes.
When you order a Zener DIY kit from RMM he includes printed instructions along with the parts.
Hey guys, been busy doing law stuff all day but now I'm back to flashlights. Got a few big shipments in today and it's all up on the website.
XTAR:
*New: WP2H charger. It's like the VP2 but without the LCD screen/voltage readout.
*New: 3 x AA BC-01 battery adapter. Allows you to use 3 x AA batteries to power the USB output.
Restock:
- MC1, VP1, VP2, SP1.
Convoy:
Restock:
- M1, S6, S2.
Super Sale:
XTAR WP2s charger. Only two left. Take the listed price + battery rebate.
Richard (or anyone) - any details on the U2 2C LED's? Are they less bright that U2 1A's? How's the tint? The U2 1D's seemed measurably less bright, but the slight rosy tint was nice.
I haven't measured them, haven't had any to use for myself. I imagine that they are probably not as bright as 1As, but still within the U2 bin. I do like the tint, it is very similar to the XP-G2 2B. Not cool, but not quite neutral/yellow like the 3C. There are also some official U2 binned 3Ds hitting the market...but they are super expensive, like 50-75% more expensive than other XM-L2s.
Ok, thanks. Been looking, but looks like no one tested the output levels. I'd love to see all in XM-L2's on copper: U2 1A vs. U2 1D vs. U2 2C vs T6 3C vs T6 4C. If I could get a clean light box setup for this, it wouldn't take much time..
I'm guessing you're going to see a slight loss as you shift warmer all the way across the line. To me, the slight loss in lumens is worth the nicer (to my eyes) tint but for others it might not be.
As I understand it all the U2 bins have the same brightness level. BUT, to change the tint think of it as a filter applied to limit the passing of green or blue or red light in order to control the color. This limits output in that color category, and effectively “dims” the overall output. So while all U2’s start off the same, the color controls yield the end result.
Same for the T6’s of course.
I have used photography lighting filters to correct a green shift in a de-domed emitter. But these have, depending on how much correction is needed, a 67-80% pass through. Meaning of course that there’s a 20-33% limit, effectively robbing lumens.
Sacrifice to gain tint perfection, or sacrifice to gain ultimate lumens. What a race… But isn’t it always true? A psi or two in the tires of a race car gains fuel mileage at cost of cornering speeds. Sacrifice. Be the fastest on the track, or be the one with enough gas to cross the line? lol
I'm pretty certain there's variations in U2's, or any bin for that matter. The 1D's are definitiely measurably lower in output. Each bin is a wide range - may be near the botttom, may be near the top. Also pretty sure CREE tests the emitter afterwards, and bins them according to the output. I understand about the tint - that's why it's hard to find high performing warms or neutrals, but CREE has T5 4C's and T6 4C's, so some tested out higher then others in that case.