| Electronics > Beginners |
| Made some magic smoke and I don't know why :/ |
| (1/3) > >> |
| MyHeadHz:
I'm making something similar to - one 12v fan in a box. It worked well from a 12v wall wart for about 2-5 minutes then stopped, though the lights (lighted fan) blinked about once per second. There was a hot component, so I let it cool. When I turned it back on it burned up. As far as I can tell the component was labelled "b62871"- my best guess is it is one of these. It is part of a voltage step-up convertor from here. However, the banggood page says input voltage from 2-24v, and output from 5-28v. On that component pdf, it says input voltage is 11v max. And yes, I have 4 more of them to try out. Eventually I plan to run it from an 18650 battery (~3.7v) to my desired fan voltage (12-15v), but atm I'm running it from a 12v wall wart (12.3v measured), to 16v out (to allow for any dropout voltage issues), which should be well under the 2amp rated for the boost converter. I thought the heat and other issues would be minimized doing this. I did accidentally hook it up backwards at first. :o The wall wart may or may not be regulated, though I have the components (lm317 and so on) to regulate it before the boost convertor if you guys think that may help. Could it be that the product page is wrong and the input voltage is out of range? Could it be a current issue? Thermal issue? I don't think a single fan would draw too much current, probably only 1 amp max, which is half the rated current. edit: sorry, I screwed up the html so half my post was hidden :p |
| Nusa:
You didn't say what part released smoke. |
| MyHeadHz:
I fixed the post, sorry. Well, there are lots of people who have fans running from them, but mine died. There are the possible issues above that I mentioned, though there could be others that I'm not aware of. The part number is my best guess based on what the part number looks like, which could very well be wrong. Also, 2 amps is not required. My fan should probably only use about 1 amp max. If it is a current issue, would I be able to add a heatsink to that tiny component? I have heatsinks, thermal tape, and thermal compound. The question for me is which rabbit hole is worth diving down. also... Boner pot? The part that smoked was what appears to be an SOT23 component. |
| MyHeadHz:
That's the component that smoked. It looks like B62871. Here is an aliexpress link of the same thing, with better pictures. |
| nrxnrx:
It looks like this guy: https://datasheet.lcsc.com/szlcsc/SDB628_C77805.pdf Also known as this: https://www.olimex.com/Products/Breadboarding/BB-PWR-3608/resources/MT3608.pdf ..and according to this thread you need to be careful with the pot, since it's possible to feed more than the allowed 6V to the feedback pin by accident. |
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