COURUI DO1 'Big Head' (Black/GRAY NOW AVAILABLE) $29.99 @ Gearbest ( use coupon: gbcourui) A long-throw modder's light!

The parasitic drain can be reduced a Lot by Taking different resistors for Battery monitoring. I do that always on my selfassembled drivers…
The zenerdiode and Zener resistor could be optimized too, but not so much.

The parasitic drain can be completely eliminated by putting a clicky switch in the tail cap.

I really really like my Courui's, but this mod alone is the cat's meow as far as the big head is concerned, flat out does away with the parasitic drain potential and keeps your cells ready to go.

This is one of the lights I could never let go...

I don’t like that solution because that’s one more thing to keep up with and operating a pair of switches located at opposite ends of the flashlight is dumb/lame/annoying/confusing/physically difficult/pick-as-many-as-you-want. It gets even worse if you are using a firmware such as the stock one where you could turn it off in firmware and forget to operate the tailswitch. Or if someone else needs to turn the light on (or off!) and sees the highly visible side-button (or they’ve seen you operating it with that) and doesn’t know or remember about the tail switch lockout. So for better or worse I’m really not a big fan of this approach!

[A series conversion is the worst case scenario at the same drain current since it has less mAh.] With a series conversion reducing the parasitic drain to 0.1mA total would take us to the point where 3000mAh batteries would be flat in 3.4 years. No need for a tail-clicky-mod there!

But of course, some of the most popular lights use this approach. The SupBeams do it, the Convoy L4, other larger Convoys, it's a fact of life. And you don't have to turn off the clicky at the tail unless you're gonna store it for a while.

Worst case scenario is needing a light and finding the batteries unable to cope with your needs due to a lack of charge.

Having a positive mechanical lockout in the tail also prevents accidental e-switch engagement when in a backpack or otherwise being transported. ;)

In the real world, perfection simply doesn't exist.

I don't know how to do all that fancy electronic wizardry, so modifying the big head in that way is beyond me. I can, however, drill a hole.

Edit: Also the tail clicky provides an instant off, in some tricky situations where that is necessary.

EditII: As an aside, immediately after proudly proclaiming this accomplishment the cats meow, you said my efforts were dumb and lame. :( My sails are shredded and my pride boat is dead in the water now. Thank you.

:P (yanking your chain, but seriously, some might cave under such criticism)

I to prefer the dual switch setup for all the reasons Dale sited. Using my driver and Tterev3’s ultimate flashlight code (with my mod to wake up in primary) the tail switch is not only a lockout switch but allows momentary use (in ANY brightness level!). This gives you the option of using the light in either grip (since when powered on the side switch also offers true momentary use).

It would be easy to Build a momentary driver with no parasitic drain…
Just a diode, a FET and maybe some resistors needed…
The switch powers the controller on over a FET, after that the controller powers himself with pulling up the same FET. Just a diode and some resistors needed to detect the momentary action
Voltage detection resistors behind all that
And voila a zero standby momentary driver…

Should also work as reversevoltage detection, so just an additional FET and maybe resitors needed…

Fair enough! I didn’t intend for it to be taken as criticism of what you are doing now so much as I intended it to be an explanation of why we shouldn’t be satisfied with the status quo. Your post was, after all, intended as a counter point to Werner’s post on parasitic drain - right? Mine is just a counterpoint to your counterpoint. :wink:

You mean that with your tweaked version of Ttrev3’s firmware I could signal using either the momentary on the side or a forward clicky on the back? And still have modes?

I think I proposed a similar idea in the Knucklehead Buck Driver Discussion Thread somewhere. I know I never prototyped it, but as far as I could tell it sounds totally viable. My suggestion was slightly different since it was intended to work with a LD2981/MIC5235/LT1761 style voltage regulator. I think I had a pulldown resistor keeping the SHDN pin low. I figured that a zener+resistor could be hooked up behind the normally-open momentary pushbutton and power the MCU whenever it was depressed. The MCU’s first instruction would be to latch an output to pull up the SHDN pin on the voltage regulator.

Mine arrived today!

Tracking number never updated though lol.

Although I am sure it made a difference in the shipping speed… I have to look when exactly I ordered, but I think it took around 2 weeks.

Parcels coming from China’s shipping and tracking nowadays are crazy, isn’t it? While some are complaining of ‘Delivered’ status in their tracking but did not receive any, yours is the opposite.

Well, I’d rather have the latter than the former! haha

you guys might want to inspect the light before you fire it up

i removed the tail cap section to replace the tiny wire with a larger one today and all three screws were loose (the ones that hold the contact plate in)

turns out they are TOO short to grab the threads on the other side.

I went across the street to my local hardware store and got replacement screws that are a hair longer and that fir just fine… cost 0.50$ lol

I also measured the lens to be 72mm x 2mm +/-0.1mm

flashlight lens sells a UCLp 73mm x 2.25mm that should fit… if it doesnt its plastic and easy to sand down 1mm on the side

just replacing the wire on the tail cap and then adding copper braids and replacing the driver wires with 22ga ones added over 120 OTF lumen.

Thanks for the heads up! I was hoping to just use this light for a day or two before having to crack it open. Oh well!

By the way, my tracking info says “Origin Post is Preparing Shipment, We have received notice that the originating post is preparing to dispatch this mail piece.” This is crazy slow. It hasn’t left the “Origin Post” yet? |(

I seem to have ordered one of these at some point in the last few weeks and forgotten about it … just got a random email from gb saying my order has shipped…
Maybe I shouldn’t browse forums after midnight.
I seem to order random things.

haha! You just lightened me up.

I have a solution for you. Change all your contact info, shipping info, everything except billing info on all flashlight related online stores to my info! Then, when you unknowingly buy a flashlight after midnight, you’ll never have to hear about it, and that will make you feel much better. 0:)

Exactly. its such a versatile FW I will NEVER use any of the AVR momentary FW’s again, there’s no reason to, UFLC does everything you can possible want. Now that we have it written in C on the tiny little 10F322 this is my go to FW for any momentary light (any my go to drivers since there is also not clicky FW for the 10F)

Oh BTW the UFLC has code for THERMAL turbo regulation!

If there was a writeup on this firmware I guess I missed it. Link me?

All FW related info and video demo’s can be found in my BLF _PIC driver thread and have been updated as of just now, there is no thread specifically on just the code.

I’m still on the lookout for the gray version!

After a couple of days of delays, the gray version’s sku will be posted within today in GB’s website. Stay tuned.