【convoy】H4 and B35AM options are updated

Hi Simon, I’m just curious. Have you stopped producing the earlier version of the linear driver with customizable modes?

If so, how many do you have left in stock? I like this driver and have an urge to hoard them if they will become unavailable. :slight_smile:

I’d just love to get a flashing kit for the 17mm 5A one! Would be good to try and write custom firmware.

I just built an S2+ with the new biscotti 5 amp driver.

Amazingly it appears to work with a lighted tailcap. No problems changing modes or using the programming function.

Good stuff!

That sounds good.What else is in your custom S2+ build?

18350 tubed orange S2+ with 2700K sst20 and 60 degree TIR optic. Made it for a friend.

This actual light won’t get the lighted tailcap. I just tested with the cap from a different light.

But you installed some bleeding resistor in the driver, doesn't it Nooner?

I made no modifications. Just installed as it came from Simon/Convoy.

It’s the 7135 Nanjing drivers w Biscotti that need the bleeder; the CC drivers are fine IIRC. If I could rewrite custom modes on those (even by rewriting/flashing firmware), I’d totally just go that.

Wow! In the past I installed a lighted tailcap in an S2+ with an LD-25, using ≈3.35 KΩ bleeder resistor. It ended up being quite bright, in fact too bright for my taste but the torch wasn't for me. And right now I have an H1-A with a 10 KΩ bleeder, yet to be installed, in a custom S21A whose parts are still to arrive home. We'll see what happens.

it’s abundant in stock ,friend

Hi, will there be XHP50.2 3V emitters and flashlights with it on sale?? I would be interested in Convoy S2+ (17mm driver for SST40 5A) XHP50.2 3V

Looking for that as well. Need such a kit, as far as I understand (not sure): 0.46€ 88% OFF|TZT CH341A 24 25 Serie EEPROM Flash BIOS USB Programmierer Modul + SOIC8 SOP8 Test Clip Für EEPROM 93CXX/ 25CXX/24CXX DIY KIT|electronic smart|bios programmerelectronic driver - AliExpress

Supporting this question. I was looking for 6V 17mm or 20mm drivers for XHP50.2, but it’s not easy to find it small enough to fit S2+
This is the closest, but not available for sale: GXB172 - 50W 17mm Single Cell Boost LED Driver

I had run a 3v xhp50.2 in my UF-20 host with the 17mm (old fet driver that doesn’t have Biscotti) and it runs great! Single Vapcell VTC6 rewrap and it’s crazy bright. That driver will do 6+ A on a fresh high drain cell, more than the new version driver with Biscotti. Yes, the UI isn’t as easy to master as Biscotti but I’ll take power over function sometimes!

Solder some additional proper value sense resistor in parallel with the stock one, and have both Biscotti and (PWM free) regulation. Problem solved, Sirstinky.

Hmm so I can make the output as good as the older one? How do I do that? What resistor do I need to add? If it’s easy I might take that nlon since I like Biscotti quite a bit over that other UI. Thanks

Where is this driver? I can’t find it on the Convoy store

I believe it is the 4 mode driver 0.1, 3, 30, 100%, but have to you ask for biscotti when you order it.

Okay, I’ll message Simon and inquire. It would be perfect for the Osram whit flat on my hunting light, 100% only

As EasyB says, the newer linear driver which can now be ordered with Biscotti is the ∅17mm SST-40 5A. The ∅20mm 6A and ∅22mm 6A SST-40 drivers will also be available with Biscotti, as Simon said here.

On the topic of raising the maximum output current for these drivers, and answering Sirstinky's question, since the drivers are regulated it must be noted that each driver mode implies a proportional voltage drop at the current sense resistor. Given that the ∅17mm 5A driver uses a 10 mΩ sense resistor (along with the ∅20 and ∅22 mm versions), we can calculate the driver's sense voltage(s). For the highest mode, 5 A, V = I × R = 5 A × 10 mΩ = 50 mV. So, the driver allows up to 50 mV of drop in its sense resistor (not verified by me yet), with proportionally less sense voltage in the lower modes.

I made a search in AliExpress for 1210 “sense” resistors of adequately low value, found 3 advertisements worth mentioning. From cheapest to most expensive as I see them, including shipping and handling:

  1. https://www.aliexpress.com/item/4000052318048.html Chinese Super Electronic market.
  2. https://www.aliexpress.com/item/32947351635.html Longqi store.
  3. https://www.aliexpress.com/item/644897575.html C&G Semiconductor.

All of them sell values which matter here. A few examples for 50 mV sense voltage:

  • A 56 mΩ (R033) resistor adds I = 50 mV / 56 mΩ = 0.893 A (0.892̅8̅5̅7̅1̅4̅).
  • A 33 mΩ (R033) resistor adds I = 50 mV / 33 mΩ = 1.515 A (1.5̅1̅).
  • A 30 mΩ (R030) resistor adds I = 50 mV / 30 mΩ = 1.667 A (1.6̅).
  • A 22 mΩ (R022) resistor adds I = 50 mV / 22 mΩ = 2.273 A (2.2̅7̅).
  • A 20 mΩ (R020) resistor adds I = 50 mV / 20 mΩ = 2.5 A.

All of them can be combined in parallel. And bear in mind that while this increases the maximum possible output, remember that you will only reach it for as long as there's enough voltage difference headroom between the input from the loaded battery and the emitter Vf at that current, after spring and contact losses and etc. You also may not want to raise the maximum current excessively, as it will affect the remaining modes proportionally. After adding an R020 in parallel with the stock R010, for example, the 30% mode will raise to 2.25 A and 3% mode to 0.225 A.

At last I'll just add that, if you remove the onboard negative thermal coefficient resistor used for temperature control, please make sure you reinforce driver cooling as much as possible, and take proper care.

Tue, 03/31/2020 - 02:06