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I've just started in basic electronics. I was simulating some basic circuits at tinkercad.com and I do not really understand why the LEDs in the two circuits in the pictures below have too much current flowing.

enter image description here

enter image description here

Note:

  • The voltage reading of the battery using the multimeter given in the website is about 7.6V

  • The circuit on the right in the second picture is for reference of a functioning circuit

I would also want to know how to spot these short circuits and how to prevent/fix them.

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    \$\begingroup\$ When learning electronics the best thing you can do is to get a bench supply though, with severely restricted current limit. Playing around with a raw battery like this makes it easy to destroy components. Also, stay away from bread boards because they are notoriously error prone. Pick up soldering early on instead. \$\endgroup\$
    – Lundin
    Commented Oct 2, 2023 at 13:52
  • \$\begingroup\$ By "shorted", I mean the LED has too much current flowing through it and the wire inside burned out, as shown in the pictures as the "star" on top of the LED. Sorry for the misunderstanding. \$\endgroup\$
    – Zachary
    Commented Oct 2, 2023 at 14:01

2 Answers 2

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For the first image, from the look of the circuit, it seems that you placed the resistor on the same connection on the breadboard (on each column, a to e are connected). So, the resistor does not do anything, and the current will not be limited. This is equal to not having any resistor on that circuit.

To use the resistor, put one terminal on the same connection as the LED and the other to the power terminal (place it instead of the green wire).

For the second one, on top of the resistors being short, you used the switch on the wrong terminals. The side pins are always connected (the right pins are connected together, and the left pins are the same). When you press the switch, the left pins will connect to the right pins. So, connect the power to, for example, the right pins, connect the left pin to the LED and connect the other pin of the LED to the resistor and the other pin of the resistor to the other power terminal. That should fix it.

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    \$\begingroup\$ This is the correct answer: all five of the holes (abcde and fghij) are shorted together so your resistors are also shorted and your LEDs have no current limiting. \$\endgroup\$
    – vir
    Commented Oct 2, 2023 at 14:24
  • \$\begingroup\$ Ohhhh, I see. Huge thanks for your concise explanation. Thank you so much! This problem has been bugging me for quite some time. Big thanks to you again! \$\endgroup\$
    – Zachary
    Commented Oct 2, 2023 at 14:26
  • \$\begingroup\$ @Zachary Lesson hopefully learned by everyone involved in this thread: 1) draw a real, proper schematic 2) worry about how to make the circuit described in the schematic. And well, the remarks about tact switches made by several users are still a very valid concern. \$\endgroup\$
    – Lundin
    Commented Oct 2, 2023 at 14:30
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You wrongly show two wires in some breadboard holes. You do not explain the pushbuttons functions. Your 9V batteries are almost dead. I see no short circuits unless the pushbuttons are wired wrongly..

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    \$\begingroup\$ Could you elaborate for the first statement? Sorry! As for the push buttons, they are there just to open the circuit if necessary. The 9V batteries are from the simulator, so I can't explain why the batteries are "almost dead" Could you also explain how to wire the push buttons correctly? Thanks. \$\endgroup\$
    – Zachary
    Commented Oct 2, 2023 at 13:35

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