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Backside is metal disc with thermal paste between it and the metal mount to which it is screwed. Input is 6.75V 200mA.

What function does the PCB circuitry serve? Is it stepping down the voltage or limiting the current, or both?

Is U1 a current limiter? voltage regulator?

Is ZD1 a Zener Diode?

enter image description here

Here is an image from someone else: https://www.eevblog.com/forum/reviews/ikea-led-power-supply/enter image description here

Mic
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    The PCB substrate is probably aluminium to transfer heat to the metal heatsink. –  Feb 02 '18 at 10:42

1 Answers1

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It's an LED driver, with regulation and constant current circuitry. U1 is a single IC LED driver and, yes, ZD1 is a Zener diode.

U1 is an AMC7136 low drop-out constant-current LED driver, or a clone of the AMC part.

TonyM
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Passerby
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  • Who is AMC? I've been unable to trace that to mfr. – Mic Feb 02 '18 at 17:45
  • Far as I can tell, some local Chinese or Taiwan semiconductor shop. If you look on candlepower forums or budget light forums (flashlight fanatics) they all look for the manufacturer. On eevblog forums, they found this ic on an Ikea led product, with the datasheet. Just Google amc7136 datasheet and it's the first result. – Passerby Feb 02 '18 at 18:14
  • Thanks for the tips. What is represented by the second number on U1, 1674 in my case, 1511 in the eevblog case. Also in my case there appears to be a logo, and none in the eevblog case. FWIW, my pcb is from the ikea jansjo lamp too, with same power supply specs. https://www.eevblog.com/forum/reviews/ikea-led-power-supply/ – Mic Feb 02 '18 at 19:21
  • It's a date or lot code, used for the manufacturer to identify different batches of an IC. Maybe 2016, day/run 74. Nothing that you can use really. As for your logo, the same part can be manufactured by many different companies (that's what I meant by clone). – Passerby Feb 02 '18 at 19:30
  • Thanks. How did you go about identifying U1? I searched before posting the question and couldn't locate a 5-pin 7136 that seemed to be a related to LEDs. Also, it seems to be sold on ebay as QX7136. What's the difference if any? https://www.ebay.com/sch/i.html?_nkw=qx7136 – Mic Feb 02 '18 at 20:03
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    "7136 led driver" is all I searched for. It would have been less of a guess if you had mentioned that it was from an Ikea lamp in the first place :P – Passerby Feb 02 '18 at 20:06
  • May be a difference. The QX vs AMC means it's a different manufacturer. Again, that's what I meant by clone. The same design is copied, ripped off, bought, out of patent and produced by multiple companies. – Passerby Feb 02 '18 at 20:08
  • Just came across this how-to: https://electronics.stackexchange.com/questions/334128/how-do-i-identify-smd-components-or-any-component – Mic Feb 03 '18 at 17:40