Convoy's 17mm / 22mm driver for SST-40 sense resistor mod feedback :-/

Thx Barkuti!

already got bunch of the thermal pads, silicone and adheaives.

Most likely this one won’t last long but for fun it will serve the purpose.

Got inspired with my 4sevens S12 (SST-90), such a small flashlight and delivers nice beam but hard to open. :(

Is resistor size 2010?

1206 imperial.

Just bought a few of these to try to mod to 7A or so. Will report my findings.

Does anyone think it’s possible to mod these for 2s input into an XHP70.2, like the zener mod on old 7135 drivers? That may be a silly question, I don’t know nearly as much about circuits as you. Thanks for experimenting with these and posting results.

mountainair26, me and others had a related conversation concerning the components in the newer Convoy drivers in the Convoy XHP35 Driver Analysis / Testing / Schematic thread. Long story short here, after I found that their onboard linear regulators work up to 18V of input.

Bear in mind the power dissipation at the onboard MOSFETs still matters. Since they're temperature controlled, they should work straight away with 2S cells driving a 2S emitter. However, they are likely to step down current aggressively, due in part to the larger input to output voltage difference. Reinforcing MOSFET/driver cooling amap and removing the onboard temperature protection is going to be key for proper 2S emitter driving, imho.

Also, unless something has changed the ∅17mm SST-40 5A 12 groups driver has a problem, with missing upper outer track (solder mask covered) which is key for cooling. Check here and my solution there among that maze of nested quotes.

So, a (XHP50n/XHP70n) 2S emitter and 2S battery S2+ build is feasible without much difficulty, for example. The only problem could be removing the heat from the driver quick enough. A copper pill can help, of course. Simon made a run of copper pills for standard S2+ flashlights/hosts, he told me to order using the current copper pill ad for the square threaded copper version, and send him a private message requesting copper pills for alu S2+ (check here).

Thx Barkuti for the updates!

Double thanks Barkuti, really appreciate it.
Does this driver from the nightwatch NL40 seen in Kawiboy’s post #322 look like it’s similar enough to the convoy to mod for current and/or remove the temp - throttle as people have done in the convoy drivers? What do you guess?

Nightwatch NI40?

The driver looks to use the same technology as the Convoy drivers, maybe it comes from the same OEM too. If so, the NTC resistor to remove is at the right side of the MCU in the above photo, below that regular resistor. The photo lacks resolution to say anything else, but that regular resistor above is probably in series with the NTC, and then connected to pin 8 on the MCU. In the Convoy drivers the NTC is connected to pin 8 at one side, and to ground by the other side. Using a resistor between the NTC and the MCU's pin 8 means a form of calibration is obtained, dampening the sensitivity with increasing value. I also thought about this while tuning Convoy drivers, but they don't have dedicated onboard space for this.

Been looking at THIS driver for a single SST20 in a Convoy S2 w/SMO, think the LED will be alright with it?
(Currently have a QLite driver in it, but I’m not happy with its limited modes and power output, adore the combo of throw and flood tho!)

I’ve used that driver with a single sst20 led in several S2+ hosts. I’ve had no issues at all.

Just received 2 of those and all is fine, no mask over the outer ring track.

Thanks for the update sida, nice to see the driver is fixed.

The drivers I received in June (4 mode and 12 group the green and red pcb’s) had no mask on the ground ring.

Oh sweetness! Thank you!
Good to hear that I don’t have to worry about instantly blowing a good LED out :wink:

I would also like to know if the 4-mode 5A driver can be resistor modded? Mine has an R010 on it and I’d like to stack two R082’s on top for a 20% increase in power, but not sure what this will do to that driver? copper pill s2+ triple SST-20-DR red leds is the light I want it to go in, so low vf in most modes. I also just want to know in general for future mods/builds. Thanks

Honestly speaking, I'm pretty sure the earlier malfunction report isn't related to driver architecture, just some mishap.

So drivers should work as expected.

mountainair26, so you want to take the “max 5A” driver, increase its maximum output to 6.22A (more heat dissipated in the driver), and drive 3x in parallel red leds with it. The low Vf of these leds means more voltage to drop in the MOSFETs, so even more heat dissipated in the driver. Good luck with this, you'll need it. The driver will throttle like crazy. If additionally you remove the thermal resistor from the driver, chances of it becoming toast increase alarmingly (it will . However, a build like that should work well with a LiFePO4 cell.

The nice way to drive 3x red leds is to set them in series and use a boost driver.

Thanks for the response and helpful info, driving red leds is difficult for me to grasp, I think I’ll go with a series mcpcb instead of parallel and boost driver, but due to the fact that a red led can have a vf of less than 2v at low current or over 3v at max current it’s tough to know how that boost driver will function.
I wish there was a perfect answer, but maybe it’s a 7135 driver like djozz has suggested, and LiFePo cells or regular li-ion charged to 3.7 to minimize voltage difference and reduce heat in a parallell set-up.
I want to use the mtn boost 17mm driver but I am not sure the voltage range from low to max with match with the vf range of the leds in series. and if I’m wrong, it’s an expensive mistake on my part for that driver.

mountainair26, the boost driver is sure to work if chosen properly, a 2S boost driver should be able to ramp up output voltage way above 7V. The H1-A and H2-C were treated extensively in Buck and Boost Drivers, Testing, Modding, and Discussion (Pic Heavy).

The H1-A which is sold now is sure to be somewhat different. A couple units I bought after Jensen567's experiments came with their OCV unlocked. Curiously I have one still unused, and its OCV is a hair above 14V (will drive triples 100% sure). It could also be being sold with a slightly different, lower inductance inductor, this was reported somewhere by another fellow.

The ∅22mm H2-C should also work (for sure with a quad in series), but take your time and ask some questions in the above Jensen567's thread.

Oh! MTN boost driver, give it a try. Power it up unloaded, you will be able to measure its OCV with a voltmeter/multimeter on its output leads. If its output voltage raises at least to ≈9V, it'll handle a triple of reds. If not, you can report that and use it somewhere else. :-)