A little update, i tried running 4 leds in 2s2p arrangement, and driver output doesn’t go above 2.52Amps. so it works normally. but efficiency goes down. compared to 3 leds in series.
1. when driver is running 3x leds in series - input voltage*input current = 14.2v*2amp. =28.4w. ( output is 24w, so 84% efficiency )
2. when driver is running 4leds in 2s2p - input voltage*input current = 14.2v*2amp. =28.4w. ( output is 16w, so 56% efficiency )
i really want to run 4 leds, but not if efficiency is really that bad. with 4 leds i can use 4x 20mm tir optics, which will give more throw compared to 3 optics.
slopegatri70, such driver does not seem to be able to handle 4 emitters in series with so low input voltage. For example, 4 white flat emitters in series require ≈12.5V at 2.5A, plus any cable and connections overhead. The effective input voltage into the driver is just very little above that, if at all, and so it cannot work properly.
If you are adamant in driving 4S emitters with such driver, raising the input voltage may work. For that, get some DC/DC boost converter you can fed with the driver's input and then attach the boost converter's output into the driver's input. Suffice to say, adjust the boost converter's output voltage to a sufficiently high value, 14+V.
Actually the input voltage i checked was on driver itself ( 14.2v), charging system gives 14.4v so almost 0.2v drop. i can’t use any dc/dc boost converter because it will stll lower the efficiency. ( motorcycle generates 11.5amps of current, only 4-4.5 amps is left for auxiliary lights after i subtract power requirements of headlight/turn signals/pump/etc.
i really thought 14.2-12.5=1.7v would be enough for this driver. i guess it’s not enough. maybe i should use 3 leds in series with 2x 20mm + 1x 26mm optics. it will have same or maybe a little bit more throw than 4s leds.
or maybe i should change the driver, but i don’t know if there’s any high quality efficient drivers available with low voltage drop.
man this experiment( modding the lights to reduce glare) is costing me alot, and there’s very little progress so far. (
I got also just from one German Guy 2 dead of those with 2R2
both with burned all in one switching chip
and it seems no one checks driver for not properly soldered parts, it is possible to let that do in a good PCB fab automatically
@Nightsword: are rest of parts same or they have changed resistors too?
I don’t understand why smaller inductor causes eff drop. It can have lower DCR and higher Isat, take a look at specs from cheap inductors from ali:
I mean with inductor of same size and this one looks like it…
Same inductor size/series usually means there's an exchange between inductance and current handling among the different series parts, being all parts of the series usually equally priced. But it clearly isn't the same size/series, they downgraded the inductor, no need to be a hawk-eye to notice imho. They stepped down to a smaller inductor with the same current rating but less inductance. They saved on production costs, and made a worse driver.
Series is different for sure, but they are pixel-perfect same size. This might looks like different current/sat specs or simply this driver has lower efficiency with smaller inductor. Bourns has good inductors (https://www.bourns.com/docs/Product-Datasheets/SRP1038A.pdf), I may give a try after ordering driver from KD.
BTW, is KD available? I’ve written some emails but no answer since week…
The 2R2 is a little bit bigger as far as I can tell. I have one of 'em right here. According to my cheap 1/10mm accuracy Aneng caliper its measurements are ≈10.25 × 10.25 × 3.7mm.
It's a bad choice what CDM has done. I may still go for it, but it is less appealing. And remember it lacks reverse polarity protection, so always stick it right. ;-)
There’s a new Convoy 22mm driver, XHP35 at 2.3 amps. Same controller as Loneoceans GXB172 so it should be easily configureable for 6 amp 6V, or just get a 12v mcpcb and resistor mod it.
hi is the driver the same in all of Malkoff drop-in’s?.
I think Nichia M61 219B V3 single mode is a Buck driver right? - is this a new or an old buck updated driver or was there something else before this?. any reason for Malkoff not to get with the times, and update? -
I have read about malkoff using old tech electronics which could do with some updating. not sure.
I know the Malkoff is a reliable light, but is the driver reliable in 2019 too?.
I’ve asked KD recently about the change - they didn’t change the picture so I charged them with not maching product description. They’ve replied this change was necessary to implement thermal management option. They claim it has a temperature step down now.
Can anybody confirm? Deny?
Edit: just to be honest: as I understood KD explanation - the inductor change was necessary to maintain the same price after implementing temperature control. So in my understanding KD traded better inductor for temperature control.
The last change was not the inductor, it was the board layout. Perhaps some new resistors, as you can see in the comparison-picture.
The Inductor was an earlyer change.
Hey, so i’m new here, my first post in fact. I’m just wondering if this driver board (KX70) has a user manual, spec sheet, or if there is any documentation or explanation anywhere as far as using it. I am hoping the driver has some user configurable settings, like modes, power levels, voltage output, and such. But I can’t find anything anywhere.
Does anyone know if this driver has a menu system? Does anyone know how it works? Does anyone have the manual or a web link?
management?