Build a light barrier yourself and how it works

Build a light barrier

A light barrier is used to switch an electrical consumer depending on the incidence of light. There are many ways to use a light barrier. You can also build these yourself.

What you need:

  • breadboard
  • 2 transistors BC547
  • 3 diodes 1N4001
  • 1 resistor 1 kilohm
  • 1 resistor 470 ohms
  • 1 potentiometer 100 kilohms
  • 1 electrolytic capacitor 47 microfarads, 16 volts or higher
  • 1 relay with a coil voltage of 9-12 volts (depending on the operating voltage)
  • Voltage source 9-12 volts (plug-in power supply)
  • 1 Light Sensitive Resistor (LDR)
  • Soldering iron and solder
  • side cutters
  • a few centimeters of wire or stranded wire to solder the components together.

The light barrier and what you need for it

Light barriers are relatively simple electronic circuits, which you can certainly build yourself.

If you already have some practice in handling the soldering iron, it will not be a problem for you to set up a light barrier yourself.

ou can get all the parts you need from electronics retailers.You also need a soldering iron with solder and a few tools to build the circuit .

So you can build a light barrier yourself

  1. First, take the circuit board and plug the electronic components onto the circuit board in such a way that you can later easily connect them to one another on the underside of the circuit board, as shown in the circuit diagram for building the light barrier yourself. Arrange the components when setting them up in such a way that the connection paths to the individual connections of the components are no longer than necessary. But when assembling the circuit board, make sure you have a little clarity when setting it up.
  2. After you have placed all the components on the circuit board, turn the circuit board over and cut off the legs of the components with side cutters so that they still stick out a few millimeters from the holes.
  3. Now solder the connecting wires of the components to the soldering points on the circuit board. After that, the components can no longer fall out of the circuit board.
  4. The next step is to wire the individual components together. Follow the circuit diagram for building the light barrier yourself. You must also note that the polarity is important for certain components. This is especially true for the electrolytic capacitor, the transistors and the diodes.
  5. If you have done the wiring according to the circuit diagram, you can try out the circuit for your self-made light barrier. To do this, connect the battery to the circuit board and set the potentiometer so that the light barrier switches at the desired brightness.

If you have set the light barrier correctly, you can connect the desired consumer to the relay.