Data Sheet

33
Lesson 10 Relay
Overview
In this lesson, you will learn how to control a relay to connect or disconnect a circuit.
Components Required
Name Qty Name Qty
NPN Transistor (S8050) 1 Relay 1
1KΩ Resistor 1 LED 1
1N4007 Diode 1 DuPont Wire 6
Breadboard 1
Component Introduction
A diode is a two-terminal electronic component that conducts primarily in
one direction (asymmetric conductance); it has low (theoretic zero)
resistance to the current in one direction, and high (theoretic infinite)
resistance in the other direction.
A relay is an electrically operated switch. It is generally used for automatic
control. Actually, it is an "automatic switch" which uses low voltage device
like Arduino to control high voltage device like 220V lamp. It plays a role
of automatic regulation, security protection and circuit switch. In this
lesson, we won't use any 220V device for safety reason, just use 5V LED for
illustration.
Connection Schematic
/RESET
3V
5V
GND2
GND1
VIN
A0
A1
A2
A3
A4
A5
SCL
SDA
AREF
GND
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
D11
D12
D13
Analog Input
Digital Input/Output
UNO R3/MEGA 2560
D1
LED0
GND
VCC
GND
IN
NC
COM
NO
TONGLING
1K
R1