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How much will it take to burn out a 1/8 watt 1 ohm resistor? (and capacitor question) Answered

I love electronics, and pranks, so I want to rig some things to "fail" by releasing smoke, and I figured what better way than resistors? I was wondering though, if I get some 1/8th watt 1 ohm resistors, will I be able to burn them out with the voltage from say, a USB port, or a double a battery or two?

I was also wondering, is there anywhere online I can get some electrolytic capacitors, not super tiny ones, but moderate size that are only a couple volts?



5 years ago

  • USB supplies 5V at 1A
  • Your 1ohm resistor wants to draw 5A
  • But your USB will only give 1A
  • So delivered power P = I×I×R = 1Watt ==> smoke
  • However IF the USB has a large filter cap
  • Momentarily P = 5×5×1 = 25 Watts ==> PoP  no-smoke
Try taking a PC power supply apart ....


5 years ago

Put more then 1/8watt through the resistor and it will eventually burn out. Shorting a resistor on USB in hopes of burning out the resistor will only result in damaging the USB port. A battery would be a better option but you won't get much smoke out of a small resistor. You'll get a good smell but that's about it.

As for the caps, The lower the voltage rating on the cap the smaller the caps are. With caps you're likely to turn them into projectiles if blown and won't see much smoke from them either.

If you really want to make some smoke and noise find some other way. Cause the really good puffs of smoke come from high power going threw medium power components. Not something you want to be toying with.