Maybe explanation for not-so-great current output on some EAST-092 drivers?

Hi,

I’ve been testing several different drivers and types of drivers in preparation for building a new triple.

I also happen to have a number of the “original” EAST-092 drivers, I think from HD-2010s, that I bought from another BLF member awhile ago, so I was testing (actually, re-testing) one of those as part of this “exercise”. I had tried these awhile ago, and one of the things that I wanted to re-check was that I recalled that on high mode, even with good batteries, emitter current was only in the 3.6+ amp range.

Now, the EAST-092 is supposed to be a DD type driver, so it seemed like it should be able to provide higher current, since it should be, I think, similar to the BLF17DD and the “NANJG-092”?

So, I hooked it up, and tested both with several different 18650s, including a couple of 20Rs that I had, and also with my bench supply. These were hooked up to a triple XP-G2 on Noctigon, and sure enough, emitter current never went higher than about 3.6 3.7 amps…

Puzzled, I dug out my old scope, and hooked it up to the gate and source pins on the FET (a 70N03), and compared the signal in low, medium, and high mode.

What I found was that in medium and low modes, the signal would toggle between “0” and 3V, whereas in high mode, the signal was steady, but only about 2.5V.

So, it seems like, at least on these EAST-092s that I have, the firmware doesn’t raise the gate signal to 100% in high mode, and that is probably why I am not seeing much higher emitter currents, even with what should be pretty good, high discharge batteries.

I don’t have any of them yet, but, on the other hand, probably the firmware in the BLF17DD and NANJG-092 drivers does raise the gate signal to 100% in high mode?

Does this make sense?

Thanks,
Jim

EDIT: If this is true, then it’s probably time for me to try making some NANJG-092s :)!!

Interesting thanks

The voltage on the gate means very little, what did the wave forms look like and what duty cycle %? Can you post pic’s / screen grab’s?

As long as the voltage is within range it is controlled by the duty cycle, lower voltage on high make sence since it would drop under load, that’s ok that it does that, again big thing is overall duty cycle as well as nice clean square sine waves with no spikes.

Per my post in OP:

Also, doesn’t the gate-source voltage govern the drain-source resistance?

CK,

I don’t know if I’ll be able to get pics. I think I did something to that one driver I was working with earlier when I did the OP, and it won’t change modes any more. I’ve tried another driver, but while I can get that to go to fast blink and SOS, I can’t seem to get it to go to any other mode.

It depends on the FET's gate characteristics. The SUD70N02-03P & AOD510 have been tested and proven to work with the Nanjg-compatible firmware & hardware. Other FETs have not. Using them hacker-style like this you can't always predict how they will behave just from what's published in the datasheets.

Jumper B+ direct to the FET's gate while the driver is running on high mode, see if/how much the output increases.

About 2 years ago I got my first HD2010, it was a Fandyfire from LightsCastle.
I did a review of it then and it measured 3.8 amps on a 26650, however I had not hardwired my VOM at that time or braided the driver spring.
After doing both of those things, the light pulls just over 5 amps on a good battery. Still does it to this day.

Now 2 years later, I have 1 Ultrafire HD2010 and 2 Tangsfire HD2010’s and none of them pull the amps of the Fandy.
All the newer East-092 drivers seem to have less balls than the old ones.

The only exception to this is the Tangsfire C8 XM-L2 from Tmart from the beginning of this year which will pull over 5 amps With the XM-L2 which is said to be harder to drive than an old XM-L T6.

So that begs the question, where did they source that driver and can it be sourced for individual sale?
Later,
Keith

Hi,

I just tried that & there was no change in output/emitter current, measured by clamp meter.

Jim

I think that it may be time for me to give in/up, and order one of the BLF17DDs, and see how that works. Maybe there is some special combination.

Also, FYI, the EAST-092s I have came with the 70N03s on them, i.e., I didn’t swap those FETs in.

Thanks,
Jim

I makes me wonder why the EAST-092s from Gearbest are different. A properly spec’ed batch or a batch of old stock?

When I got mine, I had to try several times to get an HD2010 from Tmart with a “good” EAST-092. I was fortunate that a couple of folks from Tmart used to post here at the time, and I sent the HD2010 back to them at least once, and maybe twice, before I got one that was good.

If I recall, a similar sort of thing happened when FT start selling the “new” EAST-092s (there’s a thread somewhere) where some people got good ones, and some got not so good ones.

I was told that the EAST-092s that I got (the ones I’ve been testing in this thread) were all the “original” “good” ones, and I guess that 3.6+ amps could be considered “good”, but the ones I tried out of the batch I have just don’t seem to go “true” DD on high mode… so I’ve gone ahead and ordered a BLF17DD and some of the FETs from RMM, and will see how that does.
I just went ahead and ord

There is no single cell driver that will match the 17DD/SUD70N02-03P combo.

The 'good' east-092s use a DTU06N03 FET, but still have the weird MCU & firmware issues that limit max output.

Hi,

I finally was able to get one of the drivers to get to the modes, and took some pics of the gate signal on my scope (sorry the scope is so filthy. I had to dig it out of my basement to do these, and haven’t had a chance to clean it up :():

Time scale (20 usecs/div):

Voltage scale (2 volts/div):

Low mode:

Medium mode:

High mode:

I mis-read the high mode earlier. I think that it’s actually more like 2.2V?

If jumping B+ to the gate doesn't increase the output, then the gate voltage isn't important. At least, not with that FET on that driver.

Understood.

Measure the cell voltage while on high. I bet it is being dragged down by the load. You need a cell with better dilithium crystals in it.

I’m not so sure about that… I haven’t done any experiments to prove it, but all the datasheets make it very clear that gate voltage is really critical.

:smiley:

texaspyro makes a good point. What’s the cell voltage under load? If this is a freshly charged 20R I’d expect it to be >2.5v under only a 3A load. Since you’ve got 100% duty cycle you can also just use your DMM to measure the gate voltage in case your scope is crazy…

With 20R battery:

- Vbat voltage under load: ~4.02V

  • Gate voltage using meter: ~3V

This is with the Vishay 70N03? I’ve just glanced at the datasheet and sure enough 3v+ looks like it should be fine.

What kind of current do you see when you bypass the driver (eg true DD)?