Buck Converter Not working?


i’ve been working on a project that uses a 12v button battery supply, and it’s supposed to connect to a buck converter, then to an lcd display, but when i do, nothing happens, i have no idea why, here’s a screenshot, help?

What am I looking at? And, what is a 12v button battery supply? Why is it "supposed" to connect to a buck converter? Does it or does it not? Schematic, please.
Paul

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hahah yeah i wasnt sure how to word this without being lengthy, but i have a cable connected to each side of the battery cell, with positive going to ( in the buck converter) vin, and negative to en, but when I connect (from the buck converter to the display) the 5v to vcc and gnd to gnd, it simply doesn't power on, and ive read it with a multimeter and its outputting around 4.5v?? as you may already tell im quite the noob but i just can't find an answer

Your display, what ever it is, you have not disclosed, likely has a microcontroller that MUST turn on the display. Just applying power is necessary, but insufficient. The rest of the connections must be made and the software to talk to the display controller must tell that controller to begin.
Paul

Take a close look at the second picture. There are 4 cells, maybe CR2032 packed inside a shrinking sock.

Just incredible anybody can believe getting such power, such current out of those small cells. It's even worse than a PP3.....

No, I could not believe it and still can't.
Paul

Good eye !

Can you give us a link to where you purchased your crystal ball, I think I’ll gate one too.


What did they say about E = MC2

Haha. Likely my screen was running zoomed in a lot more the usual 125%. I didn't notice either at the first look. It looked like some Black Magic to me....

Haha. That's what many new members think, a nuclear reactor inside those button cells.... Do they think about Fusion (confusing) something?

Notice the soldering on the En pin on the MPM3610
:astonished:

Magnifying it to 500%..... It's hard to se any tin at all. Good Lord...

Try negative to GND instead.

Given these cells are designed for a few mA at most, that's about two orders of magnitude less powerful than a PP3-sized 9V battery I reckon! These 3V lithium cells are absolutely puny, their selling point is the 10 year shelf-life, not the power density.

That fits my picture of them.