0
\$\begingroup\$

I've been trying to get into electronics after finding an old electronics kit in the back of my closet. It came with an Arduino Uno, a bread board, a bunch of wires, LEDs, resistors, and other things.

I decided to try to see if I could light an LED on a bread board for a few minutes before trying the Arduino.

I built this circuit:
enter image description here

When I try the circuit the LED lights but 30 seconds later it gets hot and burns out.

I'd rather know what I'm doing wrong before I burn more of my LEDs.

\$\endgroup\$
  • 2
    \$\begingroup\$ 10 bucks says you mis-wired it on the breadboard. Or have the wrong resistor. If you wired it up as your schematic shows, then it would never heat up, and probably be a pin prick of a light. 10kΩ resistor means it would get a fraction of a milliamp. A 10Ω resistor though, your talking around 90 milliamps, 4.5 times more than you should be pushing through a normal led. \$\endgroup\$ – Passerby Jul 31 '17 at 5:47
  • 2
    \$\begingroup\$ Please post a photograph of the whole circuit. I mean the actual circuit. Because I am sure something is not the way you think it is. \$\endgroup\$ – mkeith Jul 31 '17 at 5:55
  • 3
    \$\begingroup\$ 3V battery and 2.1V RED can handle 20mA with current limiting 3-2.1V = 0.9V drop/20mA = ~50 ohms but 70k would be off , while 100 ohms gives ~10mA ... 220 ohms ~5 mA \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Jul 31 '17 at 6:03
3
\$\begingroup\$

Here is how a breadboard is connected internally. Check your connections, you may have bypassed the resistors.

enter image description here

\$\endgroup\$
  • \$\begingroup\$ It looks like I screwed up the wiring. After mimicking your diagram It appears to work flawlessly. Thanks! \$\endgroup\$ – ScienceMarc Jul 31 '17 at 6:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.