This document discusses electronics components and connections. It explains that wires connected at crossroads should be spaced to form two T-junctions and wires may cross without connecting. It also defines alternating current and notes that bulbs convert energy to light and buzzers to sound, often as warnings. Solenoids and relays are also covered as components that use electromagnets to mechanically operate other devices.

1. DT LESSON ON ELECTRONICS
1. CONNECTIONS, POWER SUPPLY AND METERS
2. OUTPUT COMPONENTS

2. CONNECTIONS, POWER SUPPLY AND METERS
• A ‘blob’ shows where wires are connected (joined).
• Wires connected at ‘crossroads’ should be spaced out
slightly to form two T-junctions
• In complex diagrams, wires may cross even though
they are not connected.
• Another way is using ‘bridge’ symbol
Two T-junctions
Bridge

3. CONNECTIONS, POWER SUPPLY AND METERS

4. CONNECTIONS, POWER SUPPLY AND METERS
AC = Alternating Current, current flows in alternating direction.

5. OUTPUT COMPONENTS
A bulb converts electrical energy to light energy.
A buzzer converts electrical energy to sound.
It is often used as warning devices.

6. OUTPUT COMPONENTS

7. OUTPUT COMPONENTS

8. OUTPUT COMPONENTS
Solenoid

9. OUTPUT COMPONENTS

10. OUTPUT COMPONENTS
Primary circuit contacts