DC motor with transistor driver in Arduino - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the role of a transistor in controlling a DC motor with Arduino?

A transistor acts like a switch that allows the Arduino to control the higher current needed by the DC motor safely without damaging the Arduino board.

beginner

Why do we need a diode when using a transistor to drive a DC motor?

The diode protects the transistor and Arduino from voltage spikes caused by the motor's coil when it turns off, preventing damage.

beginner

In the Arduino code, what does the command 'digitalWrite(pin, HIGH)' do when controlling the motor?

It sends a voltage signal to the transistor's base, turning it on and allowing current to flow to the motor, making it run.

intermediate

What type of transistor is commonly used to drive a DC motor with Arduino and why?

An NPN transistor is commonly used because it can easily switch the motor's ground connection on and off, which is simple to control with Arduino.

intermediate

Explain the basic wiring connections needed to control a DC motor with a transistor driver and Arduino.

Connect one end of the motor to the power supply, the other end to the transistor's collector, the transistor's emitter to ground, and the transistor's base to an Arduino digital pin through a resistor. Also, add a diode across the motor terminals for protection.

What component protects the transistor from voltage spikes when the motor stops?

A Resistor

B Diode

C Capacitor

D LED

A diode is placed across the motor terminals to safely redirect voltage spikes caused by the motor's coil.

Which Arduino command turns the transistor on to run the motor?

A digitalWrite(pin, HIGH)

B digitalWrite(pin, LOW)

C analogRead(pin)

D pinMode(pin, OUTPUT)

digitalWrite(pin, HIGH) sends voltage to the transistor base, turning it on and powering the motor.

What type of transistor is typically used to switch the motor's ground connection?

A PNP transistor

B MOSFET

C JFET

D NPN transistor

NPN transistors are commonly used to switch the ground side of the motor in Arduino projects.

Why do we use a resistor between Arduino and transistor base?

A To limit current to protect the transistor and Arduino

B To increase current to the motor

C To power the motor

D To measure voltage

The resistor limits current flowing into the transistor base, protecting both the transistor and Arduino pin.

What happens if you connect the motor directly to Arduino without a transistor?

A Motor runs normally

B Arduino will charge the motor

C Arduino can be damaged due to high current

D Motor runs faster

Arduino pins cannot supply enough current for a motor and may get damaged if connected directly.

Describe how to connect a DC motor to an Arduino using a transistor driver and explain why each component is needed.

Think about the flow of current and protection for the Arduino.

Explain the Arduino code steps to turn a DC motor on and off using a transistor driver.

Focus on the commands that control the transistor base.