Driver Info: HX-1175b & HX-1175B1 (Pic Heavy)

Flashlight Modding and DIY Parts
157

How do I increase the sample rate on the DDS? I haven't seen any place to do that.

The inductor is actually the same size or smaller than the stock one, although I think it has higher DC resistance (more heat losses.) so it may not be the most efficient but it works well, is small enough to fit in most lights, and runs smooth. The saturation point is what I was really after since I think what happens with the stock inductor that wreaks havoc. With the stock inductor you can run pretty smooth up to a certain point then it just spikes like crazy! Sometimes you can have an LED working fine then you move the LED wires by the inductor and then it blows.

The driver fits well in the TK61 and my little mini intimidator. If you are happy with 6.5A-7A you can get away without the output capacitors but I've added them for extra insurance.

158

I just corrected a couple errors in the table in Post 155.

EDIT: Fixed again. The table is so small when I edit it that I can't really see it until it is posted. Numbers are all good now.

159

I tried to guess cell voltage under load and Vf of the emitter to get a rough idea of efficiency. Does it make sense for the driver to be more efficient on High mode?

2S 3S
High Low High Low
Input Current (Amps) 5.1 2.5 5 2.5
Emitter Current (Amps) 5 2.5 6.7 3.4
Sensor Bank (mV) 162 77 166 82
# of Cells 2 2 3 3
Cell Voltage w/Sag 3.9 3.9 3.9 3.9
Watts Input 39.8 19.5 58.5 29.25
Emitter Vf 6.8 6.25 7 6.45
Watts Output 34 15.625 46.9 21.93
Efficiency 85% 80% 80% 75%
160

Again, good info - thanks. It sounds like the included software with a DDS-120 doesn’t allow you to manually change that, but if you make a small time/division it will increase the sample rate on it’s own. This is the thread that leads me to believe that. It should be easy to tell since it displays the samplerate on the screen? There may be alternative software which would allow you to force a higher samplerate, but just making a smaller amount of time/div would do what we want here. Based on the specs I assume that the actual limit is either 50MSa/sec or 200MSa/sec.

EDIT: I could be wrong, but I think that in HKJ’s driver reviews he uses 1μs - 2μs per division.

161

I’m not sure, but I see that you did not adjust cell voltage sag for the different loads. Considering that we’re talking about 5A vs 2.5A, I’d say you’ve got to do that.

162

You could warm it over that 13A MT-G2 >)

163

wight wrote:

I’m not sure, but I see that you did not adjust cell voltage sag for the different loads. Considering that we’re talking about 5A vs 2.5A, I’d say you’ve got to do that.

Good point. I need to find a HKJ chart for the KK and adjust. I will do that later. What I really should do is set up a driver testing rig so that I can collect all the relevant info needed for this type of stuff.

164

Right now I only have two Efest IMR18500 handy. This is all jury rigged with different wires, alligator clips and magnets, but I got a reading of 5.9A.

165

Okay wight, I tested the voltage across the resistors while running the MTG at 13.45A and got a reading of .049v. I tested each resistor, and got that reading. What it means, I don’t have any clue. Hope I did it correctly.

166

Ouch! I went to take another reading before I disassembled everything, and smoke was coming out of both resistors. I sure am glad I checked this driver before it went into a light.

167

Do you see anything different in the components between the 13amp driver and the other 2 drivers. Any bad solder joints or solder bridging components?

168

I looked it all over with a jewelers loop and didn’t see anything different from the other ones. No burned or charred spots. I even tested a few solder spots with my DMM. Then again, my eyes aren’t that good.

169

Swap in new sense resistors please.

170

I’ll have to poke around to see if I can find some.

171

I swapped in some R086 resistors I scavenged from other drivers. Over 14A and started smoking. All the resistors have holes burned through the center.

172

Maybe the buck converter is oriented the wrong direction. Unfortunately they grind the label off of them. So I don't know how you could tell.

173

Thanks for testing this. You definitely got .049 and not 0.49? 13A across a total of 0.034 ohms should give about that much drop (1/2 volt). Sounds a lot like you are getting DD or as close as this driver will come (with the FET and inductor in the mix).

Could be I suppose. With QX5241 that just gives you a dead driver, but the pinout for QX9920 is different enough that it might give you DD; I’m not sure.

I think that it could also simply be a defective controller chip.

174

My DMM said .049v. I just set it to voltage, it’s got auto ranging. That’s all I know.

175

Seems like something is going on with the buck converter. Your driver is acting like mine did when I tied the PWM from an Attiny13a to the output pin of the buck converter. Wight pointed out to me then that I had basically turned the driver into a DD.

Later, I accidentally tore a leg off of that buck converter. I purchased a replacement that wight suggested may work. I will hopefully swap it tomorrow night. I'll let you know how it goes. The buck converters are fairly cheap.

176

wight,

Good call on the QX9920 buck converter. It works. Current to the emitter was as follows:

2S cells 4.5 amps (dropped fast to 4.4)

3S cells 7.15 amps

Thank you

Ouchyfoot,

Sorry it took me so long to get around to trying out the new buck converter. Here is a data sheet that wight linked me to. Here is where I bought mine from (link from this wight post).

EDIT: My chips were labled LEDA 1402. There was no indicator mark I could find for Pin 1. One of the short sides had a slight nub. I oriented the chip with the nub facing away from the inductor coil.