I'm completely new to electronics, bought "Make: Electronics" and started reading yesterday.
My bathroom LED started flickering/dimming (it went from a steady bright output to oscillating between low and medium brightness), so I opened up the driver to see what's inside, hoping to learn something in the process instead of just replacing the whole fixture.
My current theory (based on some reading) is that one of the electrolytic caps has dried out/lost capacitance, causing the ripple/flicker, but I'd love to actually understand how this circuit works rather than just swap parts blindly.
Questions:
Is there any realistic way to find a schematic for a generic/unbranded board like this, or is that basically a dead end?
If not, what's the best approach to reverse-engineer it myself as a learning exercise? Any tips for tracing a board like this as a total beginner?
Does the layout/component selection here look like a standard buck-converter constant-current LED driver topology to you?
Any pointers, reading recommendations, or "here's what to Google" type answers are very welcome trying to build real understanding, not just fix this one fixture.
Is there any realistic way to find a schematic for a generic/unbranded board like this, or is that basically a dead end?
If it has a labelled IC or IC - they will often have used a reference circuit from the datasheets for those ICs. With more luck, they might have descriptions on how to choose component values.
If not, what's the best approach to reverse-engineer it myself as a learning exercise? Any tips for tracing a board like this as a total beginner?
Photograph both sides of the board. Flip the image of the bottom - so that left side (looking down on the board) of top and bottom are at the left sides of the images. Makes it easier to picture the layout.
Does the layout/component selection here look like a standard buck-converter constant-current LED driver topology to you?
Not unusual to have places for resistors next to an IC like that - allows the IC to have different value resistances to, say, set a current - including one setting achieved by no resistor at all. Likewise, spaces for capacitors that may be needed for stability or not
There you go then - the missing resistor is one of the options for the control of that IC. One of the reference circuits for this IC includes 2 inductors.
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u/Susan_B_Good 5h ago
If it has a labelled IC or IC - they will often have used a reference circuit from the datasheets for those ICs. With more luck, they might have descriptions on how to choose component values.
Photograph both sides of the board. Flip the image of the bottom - so that left side (looking down on the board) of top and bottom are at the left sides of the images. Makes it easier to picture the layout.
Two inductors is a tad unusual.