Magicshine MJ-890 Bike Light Internals

Other Types of Lights LED Headlamps
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The owner of a bike shop I frequent is aware of my addiction to lumens and let me teardown one of the display units of a Magicshine MJ-890, possibly to mod. I forgot to get snaps of the housing and the optic it uses, but the outer diameter is >20mm since it didn't want to drop into my Convoy S2.

I'm not sure what LED is on it...tried identifying it by the looks of the substrate, but it didn't match any of the hits from the reference thread! It looks to be XP-* size though.

PCB layout. Here is the datasheet for the MH4057* charging circuit (Mirror). CC/CV with 400mA max current. The driver chip has no markings on it.

Battery and USB port. Specs say a 1500mAh LiPoly. I assume these are 2x 750mAh in parallel.

Extra shots.

Album link here

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reserved

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Led is Nichia but I am not sure which one, does not look like 219!
For modification try lowering value of R11

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TP4057

57bM gave it away in the data sheet

R0200 is the current limiting resistor…a R0100 should kick it up quite a bit :wink:
Q1 appears to be a FET

oh…see C1, pencil lead mod it or solder a 0805 330K ohm resistor across it, disable the next mode memory and have it reset back to default in 5-10 seconds so you can bypass the strobe mode

Any idea what the emitter current is?

That is a neat little all in one light though

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Unknown Nichia LED hm...

LOL Warhawk I don't think I'd want to have a bike light without a strobe mode; it's a slow strobe too ;) AFAIK there is mode memory also.

I'll get some emitter currents when I go to the shop again.

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The data sheet of the drive IC QX7137. http://senliwell.com/UserFiles/2014825111851QX7137\_.pdf

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Thanks for the info everybody. I’m keeping an eye on this one. QX7137 seems to have a much lower sense voltage than some of the other QXMD buck controllers: 100mV instead of 200mV or 250mV.

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So far I've only changed the emitter from the mystery Nichia to a dedomed XP-G2. Pardon the mess in the picture, I did clean it up afterwards ;)

http://imgur.com/a/kw4R2/embed#0 The optic is a hexagonal TIR.


I don't have any resistors on hand so I left that be, for now.

Currents at the Emitter:
Hi: 0.5A
Lo: 0.2A