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I'm trying to simulate the below circuit on a breadboard but it seems I'm missing something because the numbers don't seem to be correct. Here is the circuit I am trying to build:

enter image description here

Here is my breadboard layout:

enter image description here

I'm new to breadboards and don't know what I have done wrong.

MCG
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Mahdi Ghajary
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  • Welcome to EE.SE! Breadboard is beside the point if you are trying to simulate the circuit. If you draw the circuit here by pressing edit and click on the schematic symbol, you can simulate it here, or install a free circuit simulator such as LTspice. – winny Mar 05 '19 at 10:02
  • I am actually training with this virtual breadboard to do better with actual ones :) – Mahdi Ghajary Mar 05 '19 at 10:07
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    Did you understand/can you calculate I1 and I2 yourself before moving to breadboard? It seems you skipped some steps there. – winny Mar 05 '19 at 10:16

1 Answers1

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The breadboard layout does not match the schematic. You have the 2k2 and 5k6 resistors in parallel with each other on the breadboard, which they are not in the schematic.

Your breadboard is set up like this:

schematic

simulate this circuit – Schematic created using CircuitLab

Note that an ammeter will essentially be a short circuit, hence the zero voltage and maximum current.

Also, note that in your ammeter, the leads are back to front, which is why you are getting a negative value.

MCG
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  • the problem is I couldn't change the length of resistors in order to connect it to another column of breadboard so I used wire. Thank you. – Mahdi Ghajary Mar 05 '19 at 10:17
  • It was not just the resistors, it is also how the second power supply was connected. If this is Fritzing (looks like it) I believe there is a way to change resistor wire length? I have not used it for a few years so could be wrong! – MCG Mar 05 '19 at 10:20
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    @Madhi, the upper and lower columns on the breadboard are not connected, so if you rotate the 5k6 resistor 90 degrees (so that the right-hand end is now below the left-hand end), you can then connect it from there to the power supply. It would probably help you if you followed the convention of using red for positive and black for negative on the power supply rails. As MCG says, you Fritzing components have 'bendy legs'. You can click on the end of a leg and drag it to another hole on the prototype board. Stretching a leg is generally clearer than shortening it. – JavaLatte Mar 05 '19 at 13:55
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    Thanks for the addition @JavaLatte, I did think there was a way to extend legs in Fritzing, thanks for the confirmation. – MCG Mar 05 '19 at 14:54