Post your MT-G2 driver results here.

questions about mtg2 zener mod (4.3V, 0.5W zener and 200uohm? smd)

has anyone measured efficiency?

has anyone tested MCU behavior as 2s cells approach 6V?

Nitro, you tease!

The Zener mod fixes the mcu voltage to the Zener voltage so it should operate right up until the batteries fail. The problem is that with a fixed voltage input the mcu can’t see the battery to indicate its condition. It’s up to you to either use a protected cell(s) ( not a sure guarantee) or recognize when output drops enough that the cell(s) need charging.

I see, thanks.

I thought it reduced voltage relative to battery voltage, not reduced it explicitly to the zener rated voltage. guess i understand what a zener is now :wink:

shouldn’t really matter….given the Vf of mtg2…I should notice the brightness change unless using moonlight - even then I think the mtg2 will fail to illuminate before totally destroying batteries.

You'll definitely notice when it's time for fresh cells.

Excellent work guys!

Hey man, it’s 2 months later and I’m still waiting for that “Surprise”!

I posted this in RaceR86's High Current thread because the driver is mentioned there. Below is a copy of that post.

Ran a 5 minute test on a HX-1175B driving MT-G2 with 3 KK ICR's. The driver has the 2 FET's replaced by Comfy's 70N02's and 2 R100 resistors added to the existing stock R062's. I changed to the lower resistance FET's because Relic had reported heat issues with his T90. The HX-1175b driver is from a UF-T90 (The long light with SST-90 from Wallbuys). The cells were down a little (4.12 volts resting) from several short runs last night. The emitter was getting 10.7 amps (down from 11.3 last night). I don't know if the current was down to changing the set up or from lower cells.

The driver was loose and not heat sinked. At the end of 5 minutes, it was at 203 degrees F (95 C). The heat appears to be generated mostly by the voltage sense resistor bank. The FET's didn't feel hot. The MT-G2 lux remained unchanged through the test. Temperature of the head was 170 F (77 C) at the end of the test. The head is heavily heat sink modded. Current was down into the 9's at the end of the test, but I don't remember the first decimal.

I think this indicates the driver might be able to handle driving an MT-G2 around 11 amps (Maybe more?) with 3S cells, but I the driver should be well connected to the heat sink. I'd ordered a few of these drivers 2 different ebay vendors. Hopefully, they send me the real deal and not the HX-1175c RaceR86 received.

I believe this is the same driver you have in your 4th link in the OP (Relic's LusteFire 3XU2-X3 triple MT-G2), except that I replaced the FETs with Comfychair's FET find.

Here are what I ordered (Not yet received). WARNING: RaceR86 got a different, inferior driver, from the first guy. Others have got the proper driver though. The second buyer I have no experience with either. The specs in his ad are low, but the picture is of the HX-1175b.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=201075731413

http://www.ebay.com/itm/370877741323?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

UPDATE: Bad news. I received the drivers today and they are the inferior HX-1175c. Apparently, both ebay accounts linked above are the same seller because both orders arrived in the same package.

Zener/resistor moded NANJG105c with replaced NANJG MCU with Qlite MCU, 12 x AMC7135 350mA + 2x AMC7135 380ma giving 5 amps in SK98 with 2 x ultrafire XSL18350 .
Build topic here

Thanks guys. Links added to the op.

Added update to Post 148 above. Not good news.

Asked this vendor if these drivers are for sure HX-1175b’s and not HX-1175C’s. He said they are the “b’s”. Placed an order.

UPDATE: He sent HX-1175b1 drivers. They appear to be slightly better at this point. Thread here.

The DQG Tiny 26650 single cell boost driver runs the MTG2 just fine. 28.5mm, onboard momentary switch.

I’ve not seen this thread before. This is my shadow TC300 running a Zener modded BLF20DD off 2x samsung 25R’s. The driver has a solid brass batt+ post, 18AWG and braid on the tail spring.

This DMM is modded to read the voltage drop over an external shunt resistor.

Mine is at the emitter.

The DQG boost driver I got output reading on 'turbo' of 1.5A, 'high' is 1A. Input current with a single INR 25R is around 2.8A when freshly charged, being a boost driver that current goes up pretty dramatically as Vin falls.

I think this shows pretty clearly the limitations of what's possible with a single cell boost driver, even a large & extremely complex one.

Thanks. Both added to the OP.

Note (not that there’s any difference) but I’m actually running a 20DD in my Shadow. My bad, I’m just so used to typing 17…

Oh and BTW the FET is a Vishay 70N02 and it has a 130ohm gate resistor.

I am interested also to know can we mode the east-92 to take 2x batteries ?