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Hello I have this inverter circuit I made that is connected to a button when the button is on one led is on and the other is off and vice-versa.

schematic

simulate this circuit – Schematic created using CircuitLab

What should happen is that when the button is pressed voltage flow to one led AND to the transistor base, but it only goes to the transistor base. What am I doing wrong?


Thanks for the help everyone but I found a solution ill post it for people with the same problem in the future. I used a resistor calculator I found on the web and changed R3 to 150 ohms, removed R5 and added a 330 ohm resistor before D1. Thanks for the help anyway!

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    \$\begingroup\$ Replace D1 with a resistor in the 1k to 10k range. The sum of the voltage drops of your D1 + the base-emitter of Q1 is less than the voltage required to turn D3 on. \$\endgroup\$
    – brhans
    Commented Jul 6, 2016 at 18:02
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    \$\begingroup\$ Just to clarify, voltage does not "flow". Voltage is a difference in potential between two points. Current is what flows. \$\endgroup\$
    – DerStrom8
    Commented Jul 6, 2016 at 18:04
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    \$\begingroup\$ And 'normal' circuit-drawing convention has the ground/negative voltage rail at the bottom - it just makes your circuit easier to decipher. \$\endgroup\$
    – brhans
    Commented Jul 6, 2016 at 18:04

2 Answers 2

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schematic

simulate this circuit – Schematic created using CircuitLab

Here's how to draw the circuit.

  • Positive rail at the top.
  • Negative rail at the bottom.
  • Current flow from top to bottom.
  • Inputs on left.
  • Outputs on right.

Power flow, logic and schema becomes much simpler.

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  • \$\begingroup\$ clear post and helpful to the OP. Hope they don't design every circuit without an R2 from here on :-) Good post. \$\endgroup\$
    – TonyM
    Commented Jul 7, 2016 at 11:38
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What should happen is that when the button is pressed voltage flow to one led AND to the transistor base, but it only goes to the transistor base. What am I doing wrong?

All. Or better, the lack of a solid foundation of electrical engineering is the worst thing. Voltage don't flow! Current flow.

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