Mechatronics Systems (MCT 317) - Lecture 06

<p>RC filter or flip-flop circuit (A)</p> Signup and view all the answers

<p>Discrete position sensors (B)</p> Signup and view all the answers

<p>Inductance and eddy currents (D)</p> Signup and view all the answers

<p>Detecting pressure or mechanical stress (A)</p> Signup and view all the answers

<p>A sensor where resistance changes with temperature (C)</p> Signup and view all the answers

<p>They cannot operate in a vacuum. (D)</p> Signup and view all the answers

<p>Optical sensors (C)</p> Signup and view all the answers

<p>The emitter sends a focused beam of light to the receiver. (B)</p> Signup and view all the answers

<p>Dense materials such as metals and liquids (A)</p> Signup and view all the answers

<p>They can sense in a vacuum. (D)</p> Signup and view all the answers

<p>Set the target distance for the sensor output. (C)</p> Signup and view all the answers

<p>Surface movement interferes with sound wave reflection. (C)</p> Signup and view all the answers

<p>They operate on the principle of light. (A)</p> Signup and view all the answers

<p>It switches on its output. (D)</p> Signup and view all the answers

<p>It can block light returning from a reflector. (A)</p> Signup and view all the answers

<p>Different thermal expansion rates of metals. (D)</p> Signup and view all the answers

<p>The metal with the higher thermal expansion coefficient. (B)</p> Signup and view all the answers

<p>Both non-metallic and metallic materials (D)</p> Signup and view all the answers

<p>It does not require additional wiring for a receiver. (B)</p> Signup and view all the answers

<p>A magnetic field (C)</p> Signup and view all the answers

<p>It warps due to unequal expansion. (D)</p> Signup and view all the answers

<p>It switches off its output. (C)</p> Signup and view all the answers

<p>By sending an ultrasonic ping and measuring the time delay of echoes (A)</p> Signup and view all the answers

<p>The sensor is blinded for a short period (A)</p> Signup and view all the answers

<p>It is made from two different metals bonded together. (B)</p> Signup and view all the answers

<p>The range where echoes cannot be detected due to blindness (C)</p> Signup and view all the answers

<p>The output signal turns off. (C)</p> Signup and view all the answers

<p>Sonar technology (D)</p> Signup and view all the answers

<p>Copper (C)</p> Signup and view all the answers

<p>Inductance and power loss variations (C)</p> Signup and view all the answers

<p>The echo may occur during the sensor's blind period (D)</p> Signup and view all the answers

<p>There is an increase in eddy current loss. (C)</p> Signup and view all the answers

<p>They cannot detect targets beyond a finite sensitivity range (C)</p> Signup and view all the answers

<p>When the output switches off due to oscillator stall. (A)</p> Signup and view all the answers

<p>To allow the magnetic field to radiate out. (A)</p> Signup and view all the answers

<p>The output remains off. (C)</p> Signup and view all the answers

<p>Capacitive sensors detect only non-metallic materials. (C)</p> Signup and view all the answers

Sensors that produce a single logical output, typically represented as 0 or 1, indicating the presence or absence of a condition.

Sensors that provide a continuous range of output values, reflecting the measured quantity.

They are used to determine if a physical condition is met or not, often serving as triggers or indicators.

Mechanical switches that cause electrical contacts to either break (normally closed - NC) or make (normally open - NO) connection, depending on activation.

The undesirable phenomenon where contacts in a mechanical switch bounce multiple times during closure or opening, leading to multiple contacts registering as separate actions.

A hardware solution using either flip-flop circuitry or RC filters to suppress the unwanted multiple contacts caused by switch bounce.

Sensors that utilize the magnetic properties of inductance, reluctance, or eddy currents to measure displacement.

Sensor output can be categorized into two main types: discrete (digital) and proportional (analog), each representing different information about the measured quantity.

A proximity sensor that uses an electric field to detect the presence of an object, working with both metallic and non-metallic materials.

This switch utilizes a magnetic field to close electrical contacts.

An ultrasonic proximity sensor sends out a sound wave and measures the time it takes for the echo to return, determining the distance to an object.

The furthest distance an ultrasonic sensor can detect an object.

The area within the sensor's beam angle where echoes are not detectable due to the sensor's own signal.

The cone-shaped area of the sensor where sound waves can travel.

The sensitivity of the receiver that determines the maximum distance it can detect an object.

The point beyond which the returning echo signal is too weak to be detected.

Inductive proximity sensors work by detecting changes in inductance caused by the presence of a metallic object near the sensor's coil.

The sensor's coil creates an alternating magnetic field that extends beyond its face. When a metallic object enters this field, it creates eddy currents that oppose the magnetic field, causing a change in inductance.

Inductive proximity sensors are designed to detect only metallic objects. They won't respond to non-metallic materials.

The oscillator in the sensor circuit generates an alternating magnetic field. This field is used to sense the presence or absence of a metallic object.

When a metallic object enters the sensor's field, the eddy currents in the object load the oscillator circuit, causing the output amplitude to decrease.

When the oscillator amplitude drops below a threshold level, the trigger circuit activates, causing the output switching device to turn 'on'. This indicates the presence of a metallic object.

Inductive proximity sensors are commonly used for detecting the presence or position of metallic objects in various applications like automated manufacturing, robotics, and material handling.

Capacitive proximity sensors work by detecting changes in capacitance between two parallel plates when a non-metallic object is brought near the sensor.

A type of optical sensor where the emitter and receiver are separated and aligned in a line. Light is transmitted from the emitter to the receiver, and the sensor detects changes in the transmitted light beam.

A variation of the thru-beam sensor where the emitter and receiver are located in the same unit. Light reflects off the target and returns to the receiver.

A type of optical sensor that combines the emitter and receiver in a single unit. It requires a reflector to reflect light back to the sensor. It works similar to a thru-beam sensor.

A discrete sensor that uses the expansion properties of different metals due to temperature changes. Consists of two bonded metals with different expansion coefficients. When temperature increases, the strip bends based on the expansion differences.

The property that describes how much a material expands for a given change in temperature.

Sensors that measure position or displacement, detecting the presence or absence of an object or a change in position.

Ultrasonic sensors emit sound waves to detect objects. They work well with dense materials like metals and liquids but struggle with soft materials or liquids with surface ripples.

Ultrasonic sensors can adjust their sensing range, allowing you to set the distance at which they trigger an output.

Optical sensors use focused beams of light to detect objects, regardless of colour or reflectivity.

Thru-beam optical sensors consist of two units: an emitter that sends a light beam and a receiver that detects it. When the beam is blocked, the sensor triggers an output.

Optical sensors are versatile as they can sense objects in a vacuum and work well with various materials, unlike ultrasonic sensors.

Optical sensors use focused beams and are designed to avoid interference between sensors placed close together.

Inductive and capacitive proximity sensors are best suited for sensing extremely short distances, unlike ultrasonic and optical sensors that can act over greater distances.

Ultrasonic sensors, though effective with dense materials, struggle with soft materials or liquids with ripples because sound waves are absorbed or reflected.