Any of y'all know what's going on with this resistor? Brown black gold gold black is a bit unusual. From what I've found I'm pretty sure it's a 1 ohm resistor (±5%), but I'm unsure about that last black band. From what I've found, it's either the temp. coefficient, the reliability, or it's telling me it's a wirewound resistor. Given this is a generic 5V power supply, I *think* it's the last one, but can anyone confirm?
@Felthry No, there's not temperature measuring circuitry there. It's literally just sitting between one of the mains inputs and the bridge rectifier. The only reason I can think of that it'd specified the tempco is because it just happened to be the resistors they had lying around (which, in a cheap power supply, I suppose you'd never know)
@auravulpes It could be, but why would you use more expensive resistors when cheaper ones are also available?
That positioning suggests it's part of a capacitive dropper, incidentally.
@Felthry Like I said, you never really know with cheap electronics. That said, you're probably right about it not being one.
Also, it's not a capacitive dropper. It's using a transformer to step down the voltage
@auravulpes @Felthry if it's a tolerance indicator it might be part of a failed batch (as in, it was supposed to be better specs but failed the quality checks, but it's still good enough as a regular resistor)
@emptyfortress No, the second gold band is definitely tolerance.
@auravulpes Do you have a multitester to confirm the stripes handy?
@drwho Unfortunately not
@auravulpes Hmmm... this translator doesn't seem to be helpful:
This suggests reading the stripes from right to left, after comparing the image you posted to the one here:
https://electronics.stackexchange.com/questions/171289/4-5-band-resistor-extra-black-band
Which, plugging the values back into that converter suggests that it's a 44 ohm resistor @ 1% tolerance.
Also this:
This discussion of a similar resistor
https://www.eevblog.com/forum/projects/is-this-a-fusible-resistor/
refers to it as a "fusible resistor", which will not catch fire when it blows. You might see if that would make sense in the design, and also look for other independent confirmation.
@ed_packet That would seem to make sense, and would explain why it's spot on the pcb is marked "FR1". Thank you!
You're welcome. My secret search weapon for finding this was looking for the exact phrase "brown black gold gold black", finding mostly forum postings, and not finding it listed in any of the easy to find resistor decoder charts.
If you happen to blow that one, it appears that Digikey has several vendors that have "fusible through hole resistors", like this listing only by way of example
https://www.digikey.com/en/product-highlight/y/yageo/fusible-through-hole-resistors
@auravulpes Wirewound would make sense in a context like that; it could also be a tempco but I don't see why that would be specified for a resistor in a cheap power supply unless there's some sort of current sensing going on using that resistor (but if you're doing current sensing to the point where you need a specified tempco, you need to also be able to measure the temperature and i don't see any sort of temperature measurement happening here)