Circuit Elements:

• Power Source (N and L):
  
  • The terminals of the power source are marked with „N” (neutral) and „L” (line).
  • The neutral wire is represented by a blue line, and the line wire by a red line.
• Ground (PE):
  
  • The ground wire is represented by a green and yellow line, but in this simple circuit, it is not connected to any component, being present only for completeness.
• Switch:
  
  • The switch is represented by a symbol with two points connected by a line that can be opened or closed.
  • It controls the current flow in the circuit.
• Light Bulb:
  
  • The light bulb is represented by a standard light bulb symbol.
  • It lights up when the circuit is closed, and current passes through it.

Circuit Connections:

• The line wire (L) is connected to one terminal of the switch.
• The other terminal of the switch is connected to one terminal of the light bulb.
• The other terminal of the light bulb is connected to the neutral wire (N).
• The ground wire (PE) is not connected to any component in this simple circuit.

Circuit Operation:

• When the switch is closed (connected), electric current can flow from the power source through the line wire (L), pass through the closed switch, the light bulb, and return to the power source through the neutral wire (N). Thus, the light bulb lights up.
• When the switch is open (disconnected), the current flow is interrupted, and the light bulb turns off.

Basic Principles:

• Current Flow: Electric current flows from the line terminal of the power source, passes through the switch, the light bulb, and returns to the neutral terminal.
• Role of the Switch: It controls whether the circuit is closed (light bulb on) or open (light bulb off).
• Safety: It is important to ensure that all connections are made correctly to avoid short circuits and to protect equipment and users.