Catalog / Actuators - Electronic Components Cheatsheet

Actuators - Electronic Components Cheatsheet

A concise cheat sheet covering various types of actuators used in electronic systems, their principles of operation, key characteristics, and common applications.

Actuator Fundamentals

Actuator Types Overview

Actuators are components that convert energy into motion. Common types include:

  • Electric Actuators: Utilize electrical energy (motors, solenoids).
  • Hydraulic Actuators: Use pressurized fluid to generate force.
  • Pneumatic Actuators: Use compressed air to generate force.
  • Thermal Actuators: Employ heat to produce motion.
  • Shape Memory Alloy (SMA) Actuators: Utilize the properties of SMAs to change shape.

Key Performance Parameters

Force/Torque:

The amount of push or pull (force) or rotational effort (torque) the actuator can exert.

Speed:

The rate at which the actuator can move or rotate (e.g., mm/s, RPM).

Stroke/Angle:

The linear distance (stroke) or angular range (angle) over which the actuator can move.

Resolution:

The smallest increment of movement the actuator can achieve.

Power Consumption:

The amount of energy the actuator requires to operate.

Duty Cycle:

The percentage of time the actuator can operate continuously without overheating or damage.

Control Methods

Open-Loop Control:

Simple control, no feedback. Accuracy depends on actuator characteristics and external factors.

Closed-Loop Control:

Uses feedback (e.g., position sensor) to achieve precise control. Requires a controller (e.g., PID controller).

PWM (Pulse-Width Modulation):

Varies the duty cycle of a signal to control actuator speed and force. Commonly used with DC motors.

Electric Actuators

DC Motors

Principle:

Converts electrical energy into mechanical rotation using magnetic fields.

Types:

Brushed, Brushless (BLDC), Stepper Motors, Servo Motors.

Applications:

Robotics, automation, consumer electronics, automotive.

Control:

Voltage control (speed), PWM control, encoder feedback (position).

Advantages:

Simple control (brushed), high efficiency (BLDC), precise positioning (servo, stepper).

Disadvantages:

Brushed motors have limited lifespan, BLDC require more complex control.

Solenoids

Principle:

Electromagnetic coil that generates linear motion when energized.

Types:

Pull-type, push-type, rotary solenoids.

Applications:

Valves, latches, locking mechanisms, printers.

Control:

On/off control (energized/de-energized).

Advantages:

Simple, fast response, low cost.

Disadvantages:

Limited stroke, high power consumption during activation.

Piezoelectric Actuators

Principle:

Deforms when voltage is applied (inverse piezoelectric effect).

Types:

Multilayer, bending actuators.

Applications:

Precision positioning, microfluidics, nanopositioning.

Control:

Voltage control (displacement).

Advantages:

High resolution, fast response, high force.

Disadvantages:

Small displacement, high voltage requirements.

Hydraulic and Pneumatic Actuators

Hydraulic Cylinders

Principle:

Uses pressurized fluid (hydraulic oil) to generate linear force and motion.

Types:

Single-acting, double-acting, telescopic cylinders.

Applications:

Heavy machinery, construction equipment, industrial automation.

Control:

Flow control valves (speed), pressure control valves (force).

Advantages:

High force capacity, precise control.

Disadvantages:

Requires hydraulic power unit, potential for leaks, messy.

Pneumatic Cylinders

Principle:

Uses compressed air to generate linear force and motion.

Types:

Single-acting, double-acting cylinders.

Applications:

Industrial automation, packaging machines, pneumatic tools.

Control:

Flow control valves (speed), pressure regulators (force).

Advantages:

Clean, relatively low cost, fast operation.

Disadvantages:

Lower force capacity compared to hydraulics, requires compressed air supply.

Pneumatic Motors

Principle:

Uses compressed air to generate rotary motion.

Types:

Vane motors, piston motors, turbine motors.

Applications:

Pneumatic tools, rotary actuators.

Control:

Flow control valves (speed), pressure regulators (torque).

Advantages:

High power-to-weight ratio, explosion-proof.

Disadvantages:

Noisy, less precise control compared to electric motors.

Emerging Actuator Technologies

Shape Memory Alloy (SMA) Actuators

Principle:

SMA changes shape when heated or cooled due to phase transformation.

Types:

Wires, springs, strips.

Applications:

Robotics, biomedical devices, aerospace.

Control:

Temperature control (heating/cooling).

Advantages:

High force-to-weight ratio, compact, silent.

Disadvantages:

Slow response, limited cycle life, hysteresis.

Electroactive Polymers (EAPs)

Principle:

Polymers that change shape or size when stimulated by an electric field.

Types:

Dielectric EAPs, ionic EAPs.

Applications:

Robotics, artificial muscles, sensors.

Control:

Voltage control (displacement).

Advantages:

Lightweight, flexible, biocompatible.

Disadvantages:

Low force, low bandwidth, limited lifespan.

Microactuators

Principle:

Miniature actuators fabricated using microfabrication techniques (MEMS).

Types:

Electrostatic, thermal, piezoelectric microactuators.

Applications:

Microfluidics, biomedical devices, optical switches.

Control:

Voltage or current control.

Advantages:

Small size, low power consumption, high integration potential.

Disadvantages:

Low force, complex fabrication, stiction issues.