Brief switch controlled indicator LED circuit

Lighting an LED is a simple circuit that is a part of many demonstration circuits.

Simple pushbutton switch controlled LED circuit schematic diagram by electronzap electronzapdotcom
Simple pushbutton switch controlled LED circuit schematic diagram by electronzap electronzapdotcom

220Ω or higher resistor will work well with a 5V power supply. A video demonstration and explanation of this circuit is included below, plus written text for those that prefer to read about it.

Main points:

  • LED must be inserted in the right direction (forward biased)
  • Resistor value must be high enough value to limit current enough to protect the LED (no more than 20mA) and prevent the resistor from overheating. Covered in more detail below.
  • An open switch cuts off current flow to the entire circuit. A closed switch lets current flow as is determined by the other series (connected end to end) components and power supply voltage.

Become a Patron!

A one time or monthly donation to my Patreon (link above) of any amount will help a lot!

Video

Quick switch controlled LED circuit schematic to breadboard build

To check out my YouTube videos (please make sure to subscribe!) click this link! https://www.youtube.com/c/electronzap/videos

Important topics to understand:

Voltage across LED and protective resistor schematic diagram by electronzap
Voltage across LED and protective resistor schematic diagram by electronzap
  • Keep current below 20mA for most LEDs, and resistor power dissipation below 1/8W (0.125W) for the commonly rated 1/4W (0.25W) resistors. Covered in more detail below.
  • LED must be inserted in the right direction (forward biased) in order to light up. While forward biased, the Anode is connected toward the positive side of the power supply, whereas the cathode is connected towards the negative side of the power supply (usually called ground). Anode is usually the longer lead of the component and the Cathode is the shorter lead if they haven’t been cut. Cathode also commonly has a flat edge along the rim.

To support my work with  a one time donation through paypal, please check out this link! https://www.paypal.com/paypalme/electronzap

  • Resistor value is selected to be high enough to limit current to no more than 20mA to protect the LED. I = V/R (current in amps equals voltage in volts divided by resistance in ohms).
  • Resistor also must not overheat. Most are rated at 1/4 watt (0.25W), but should still be limited to not more than 1/8W (0.125W) for extended periods of time, and be given access to room temperature air. P = IV (Power in watts equals current in amps through a component times the voltage in volts across the component)
  • Forward biased LEDs typically drop about 2-3V of the power supply voltage from reaching the current limiting resistor. You need to subtract that voltage from the supply voltage in order to get a more accurate calculation of the current that will flow through the series components.

I also set up a GoFundMe if you would like to donate that way! https://www.gofundme.com/f/help-fund-learning-electronics-tutorials

Brief circuit schematics with short video – List of pages

Next topics



As an Amazon associate, I earn from qualifying purchases.

Home page