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2022.08.24 motor

Driving Circuits for Brushed DC Motors - Summary

Brushed DC Motor

Up to this point, various methods for driving brushed DC motors have been explained. This article summarizes the preceding discussions in concise tables titled "Driving Circuits for Brushed DC Motors and Features" and "Features and Application Examples of Brushed DC Motors."

Driving Circuits for Brushed DC Motors and Features

Circuit name Possible rotation
operations
Rotation rate
control
Advantages Disadvantages
H-bridge Forward rotation, reverse rotation,
stopped (Hi-Z),
breaking
Not possible    
H-bridge+High-side voltage
linear control
Forward rotation, reverse rotation,
stopped (Hi-Z),
breaking
Possible  
  • Large power consumption
  • ・Larger circuit scale when using MOS power transistors
BTL amp linear voltage driving Forward rotation, reverse rotation,
breaking
Possible
  • ・All operations possible with two-input linear driving
  • Large power consumption
  • ・Larger circuit scale
  • ・Separate circuit needed for high output impedance
PWM driving with H-bridge circuit Forward rotation, reverse rotation,
stopped (Hi-Z),
breaking
Possible
  • Low power consumption
  • ・Supports DC voltage input
  • ・PWM circuit configuration required
  • ・Noise source
PWM driving in the form of
BTL amplifier input
Forward rotation, reverse rotation,
breaking
Possible
  • Low power consumption
  • ・All operations possible with two-input linear driving
  • ・Poor linearity
  • ・Separate circuit needed for high output impedance
  • ・PWM circuit configuration required
  • ・Noise source
Single switch On/Off One- direction rotation,
stopped (Hi-Z)
Not possible
  • ・Simple circuit
  • ・Diode required
  • ・Sudden stopping not possible
PWM driving One- direction rotation,
stopped (Hi-Z)
Possible
  • Low power consumption
  • ・Diode required; Diode heat generation must be considered
  • ・Sudden stopping not possible
  • ・PWM circuit configuration required
  • ・Noise source
Half-bridge On/Off One- direction rotation,
stopped (Hi-Z),
breaking
Not possible
  • ・Diodes unnecessary
  • ・Sudden stopping possible
  • ・Control input configuration must be considered (one or two inputs)
  • ・Simultaneous-on prevention needed
PWM driving One- direction rotation,
stopped (Hi-Z),
breaking
Possible
  • Low power consumption
  • ・Diodes unnecessary
  • ・Sudden stopping possible
  • ・Control input configuration must be considered (one or two inputs)
  • ・PWM circuit configuration required
  • ・Noise source

Features and Application Examples of Brushed DC Motors

Features of Brushed DC Motors
Advantages Disadvantages
  • ・Easily made smaller, lighter
  • ・Good efficiency
  • Low cost
  • Rotates just by applying a voltage
  • Driving possible even at low voltages (operation possible at 1.5 V with 1 battery)
  • ・Linear proportionality between rotation rate and applied voltage
  • ・Rotation rate decreases in proportion to load
  • ・Large startup torque
  • ・Torque proportional to current
  • Simple construction with just two wires
  • Rotation direction changes with power supply polarity
  • Brush means short lifetime
  • Tends to be noisy
  • Electric noise tends to occur
  • ・Poor constant-speed characteristics
  • ・DC power supply necessary
  • ・Large currents flow when overloaded
  • ・Sparking may occur
  • ・Friction torque loss due to brush contact
Application Examples of Brushed DC Motors
ODD(Optical Disc Drive)
DVD/Blu-ray drives for PCs/game systems
Blu-ray recorders/players
Loading: disc insertion/ejection
Ink-jet printers
Multifunction printers
Paper feed
Carriages: printing head movement
Scanners
PPC(Plain Paper Copier) Paper feed
Digital still cameras Zoom, iris (diaphragm), lens cap
Mobile phones, tablet PCs Vibrators
Toys General operations
Models, radio-controlled devices: driving, direction control
Game controllers: vibration
General home appliances Hair dryers: air blowing
Shavers: blade rotating, reciprocal motion
Tooth brushes: vibration
Refrigerators: icemaker tray rotation
etc.
Tools Screwdrivers, drills, saws etc.: rotation
Automotive Power windows: opening/closing
Mirrors: opening/closing, angle adjustment
Door lock: locking/unlocking
Air conditioner dampers: changing air direction
Corner pole: raising/lowering
Head lights: light direction adjustment
Car navigation system: display advance/retract
etc.

Application examples are representative; in addition to these, there are various other applications that exploit the features of brushed DC motors.

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