Proximity Sensor working. Inductive proximity sensor, capacitive proximity sensor. proximity switch

Summary

The video explains how proximity sensors work, focusing on inductive and capacitive types. Proximity sensors detect an object's presence or movement without physical contact, converting this information into an electrical signal. Capacitive sensors operate on the principle of a parallel plate capacitor involving dielectric materials, and can detect both metallic and non-metallic objects. Inductive sensors detect metal targets using components like coils and oscillators to generate electromagnetic fields and eddy currents, following Faraday's and Len's laws of induction. Each sensor type has specific uses and operational principles, which are detailed in the video.

Highlights

• Proximity sensors work by detecting presence without contact, using signals. 🌟
• Capacitive proximity sensors rely on parallel plate capacitor principles. ⚡
• Inductive proximity sensors use electromagnetic fields to detect metal. 🔗
• Both sensor types cater to specific detection needs with unique mechanisms. 🔧
• The creator encourages engaging with future content by subscribing. 🔔

Key Takeaways

• Proximity sensors detect objects without physical contact, using electrical signals. 🎯
• Capacitive sensors utilize parallel plate capacitors and can detect various types of materials. 💡
• Inductive sensors are ideal for detecting metallic objects, employing electromagnetic fields. 🔍
• Different proximity sensors have unique operational principles based on their structures. 🛠️
• The video encourages viewers to subscribe for more informative content from Instrumentation Academy. 📢

Overview

In the intriguing world of electronics, proximity sensors play a vital role. These devices detect an object's presence without needing to physically touch it, instead converting these interactions into electrical signals. The video delves into the intricate workings of these sensors, emphasizing their efficiency and utility in various applications.

Capacitive proximity sensors are spotlighted first, which function using the principles of parallel plate capacitors. They boast the ability to sense both metallic and non-metallic objects by measuring changes in capacitance due to nearby objects. This type of sensor stands out for its versatility and wide range of applications, showcasing the marvels of modern technology.

Next, the video breaks down the workings of inductive proximity sensors. These sensors are specialized for detecting metal objects by generating and using electromagnetic fields. Through a series of technological principles including Faraday's law of induction, these sensors offer precision and reliability where metal detection is essential. Watching this video from Instrumentation Academy reveals detailed insights into how these sensors contribute to the world of automated and sensing technologies.

Chapters

• 00:00 - 00:30: Introduction to Proximity Sensors In the "Introduction to Proximity Sensors" chapter, the fundamental concept of proximity sensors is discussed. Proximity sensors are explained as devices that can detect the movement or presence of objects without requiring physical contact. This detection is then converted into an electrical signal, differentiating them from devices like limit switches which require physical contact to detect objects.
• 00:30 - 05:30: Working of Capacitive Proximity Sensors Proximity sensors are non-contact devices that detect the presence of an object without physical touch, thus preventing any damage to the object. Unlike sensors with moving parts, these transmit signals when an object enters their proximity. Various types of proximity sensors exist, each uniquely capable of detecting objects.
• 05:30 - 10:00: Types of Capacitive Proximity Sensors The chapter discusses types of capacitive proximity sensors with a focus on the capacitive proximity sensor and how it differs from the inductive proximity sensor.
• 10:00 - 15:00: Working of Inductive Proximity Sensors The chapter explains the construction and working of inductive proximity sensors, focusing on the components and materials used. It describes that the sensors consist of conductive parallel plates separated by a dielectric material such as plastic, glass, or porcelain. These conductive plates are typically made of metals like Aluminum or Tantalum and remain electrically neutral due to an equal number of positive and negative charges. The chapter also highlights how connecting a power source or battery to the capacitor can affect the function of the sensor.
• 15:00 - 16:30: Conclusion In this conclusion chapter, the movement of electrons from the negative terminal of a battery through conductive wires is described. Upon reaching the capacitor's right side plate, the dielectric material inside the capacitor resists the movement of these electrons to the left side plate. This results in an accumulation of electrons, or negative charge carriers, on the right plate, causing an imbalance as they outnumber the protons, or positive charge carriers, on the same plate. This phenomenon explains the basic operation of a capacitor in an electrical circuit.

Proximity Sensor working. Inductive proximity sensor, capacitive proximity sensor. proximity switch Transcription

• 00:00 - 00:30 Hello Everyone Welcome to Instrumentation Academy In this video we will discuss what is  a Proximity Sensor and How it works. Proximity Sensors are sensors that detect the  movement or presence of an object without making   physical contact with the object and converts that  information captured into an Electrical signal. Devices such as limit switches detect an  object by physically contacting it, but
• 00:30 - 01:00 proximity sensors detect the presence of an  object without touching it. As these sensors are non-contact sensors they do not cause any damage to the object. proximity sensors do not use any type of physical moving parts, instead they allow signals to transmit through them, when something that is being monitored comes in close proximity of the sensing area. There are many types of proximity sensors and  they each sense the presence of an object in
• 01:00 - 01:30 their own distinct ways. The two most commonly used  proximity sensors are The capacitive proximity sensor and the Inductive proximity sensor. Now  let's discuss about Capacitive Proximity Sensors. Working Principle of Capacitive Proximity Sensor. Capacitive proximity sensor is based on  the principle of a Parallel Plate Capacitor. Parallel Plate Capacitor consists of two parallel  plates
• 01:30 - 02:00 that are separated by a dielectric material which is a poor conductor of electricity such  as plastic, glass or porcelain. The two parallel plates are conductive and they are usually  made of Aluminum, Tantalum or other metals. A metal plate typically has an equal amount of  positively and negatively charged particles, which means it is electrically neutral. if we connect a  power source or a battery to the capacitor
• 02:00 - 02:30 a large number of electrons start moving from the negative  terminal of the battery through the conductive wire. when these electrons reach the right side  plate of the capacitor, the dielectric material will strongly oppose the movement of electrons from the right side plate to left side plate. as a result number of electrons that is the  negative charge carriers on the right side plate of the capacitor will be higher than the number  of protons, that is the positive charge carriers
• 02:30 - 03:00 Due to this the right side plate of the  capacitor becomes negatively charged   at the same time the electrons on the left side  plate experience a strong attractive force from   the positive terminal of the battery. As a result  the electrons leave from left side plate and will be attracted towards the positive terminal of the battery Due to this the number of protons will be higher than the number of electrons in the left side plate and as a result the left side plate of the capacitor becomes positively charged. This is how the charging of capacitor takes place.
• 03:00 - 03:30 The right side plate has now  developed a net negative charge   and the left side plate has developed an  equal net positive charge. this creates an electric field with an attractive force between  them which holds the charge of the capacitor. The ability of a capacitor to store electric  charge when a voltage is applied is called   capacitance and quantity measuring  the ability of a dielectric material
• 03:30 - 04:00 to store charge is called dielectric  constant. the capacitance of a capacitor is directly proportional to the dielectric constant of the material between the two plates and inversely proportional to the distance between the two plates. There are two types of Capacitive Proximity Sensors The first one is Dielectric type Capacitive Proximity Sensor and the second one  is Conductive type Capacitive Proximity Sensor.
• 04:00 - 04:30 Dielectric type of capacitive proximity sensor. Dielectric type of capacitive proximity sensor can detect any target that has a dielectric constant greater than air. It has two parallel plates inside the sensing head which operates like  an open capacitor. Here air acts as the dielectric when no target is present the capacitance between  the plates will be very less. These plates are linked to an oscillator and a detector circuit.
• 04:30 - 05:00 As the target which has dielectric constant more than air comes near to the sensor the capacitance between the plates increases. Increase in capacitance increases the  amplitude of the oscillation of the oscillator. when the oscillation exceeds a specific value, the detector turns on the output of the sensor. when the target object moves away from the  sensor the oscillation amplitude decreases   and when it falls below a threshold value  the sensor returns to the initial state.
• 05:00 - 05:30 Dielectric type capacitive proximity sensors  will sense both metallic and non-metallic objects. Conductive type of Capacitive Proximity Sensor In conductive type capacitive proximity sensor there is only one capacitor plate inside the sensor the target itself becomes the other plate of the parallel plate capacitor. The plates of a parallel plate capacitor should be conductive, so this type of sensor is used if the target
• 05:30 - 06:00 is an electrically conductive material. The air gap between the sensor and the target  functions as the dielectric. The plate inside the sensor is connected to an oscillator circuit  that is used to generate an electrostatic field. As the conductive target approaches the sensor, the distance between the two plates decreases   due to which the capacitance increases and  results in increase of oscillation amplitude.  once the oscillations exceeds a  predetermined value, output signal
• 06:00 - 06:30 from the sensor is generated which indicates  that the target has reached near the sensor. Now let's move on to Inductive Proximity Sensor. Inductive proximity sensors are used to detect metal targets. An inductive proximity sensor has  four main components. the first one is the coil. The coil generates necessary electromagnetic  field a cup shaped magnetic core holds the coil.
• 06:30 - 07:00 This core is necessary to concentrate the  coil's magnetic field on the front area of   the sensor. The second part is the oscillator The oscillator is generally an LC oscillator. it produces radio frequency which helps to  generate an electromagnetic field. The third part is the trigger circuit. The trigger circuit senses the change in amplitude of oscillation and gives the signal to the output circuit.
• 07:00 - 07:30 The last part is the output circuit. The output circuit has a transistor after receiving the signa,l  the transistor switches on and gives an output. Working principle of Inductive Proximity sensor   Inductive proximity sensors operate on  the basis of Faraday's law of Inductance.   According to Faraday's law of Induction, when  an electrically conducting object is placed in
• 07:30 - 08:00 a time varying magnetic field, an electric current  called a Eddy current will be generated in the object   and according to the Len's is law, the Eddy  current creates a magnetic field in a conductor   and this eddy current magnetic field  opposes the magnetic field which created it. Now let's discuss the working of an Inductive  Proximity Sensor The proximity sensor is installed in the area where we need to sense the presence of an electrically conductive target object.
• 08:00 - 08:30 when the sensing coil in the oscillation circuit  is supplied with an alternating current, a changing   magnetic field is created around the coil. when the target object enters this electromagnetic field some of the electromagnetic energy is transferred to the object according to Faraday's law of Induction an electric current called Eddy  current will be generated in the object. This eddy current produces another magnetic field  called Eddy current magnetic field and it opposes the magnetic field which created it.
• 08:30 - 09:00 As the eddy  current magnetic field opposes the magnetic field of the coil, the intensity of the magnetic field of  the coil reduces. As the target comes very close to the sensor the eddy current increases, decreasing  the amplitude of the electromagnetic field The trigger circuit monitors the amplitude and  when the amplitude goes below a predetermined   level the output state of the sensor switches from  its normal condition.
• 09:00 - 09:30 As the target moves away from the sensor the amplitude of the electromagnetic  field increases and at a predetermined level the trigger switches the output state of  the sensor back to its normal condition. By this we come to the end of this video  if you like our video please click the like button below and make sure to click the  subscribe button and the bell icon also so that you can get notifications of
• 09:30 - 10:00 our  further videos Thank you have a Nice day