Skip to main content

What is Relay?


Relay is an electrically operated switch that opens and closes the circuit by receiving electrical signal from the outside source 

Relay Type:

Ø  Relay technology is divided into two categories

1. Movable Contacts

2. No-Movable Contacts

 

Mechanical Relay



                

 

Solid State Relay

                    

 

Relay Types:

Mechanical Relay

Ø  This relay has contacts that are mechanically actuated to open/close by a magnetic force

Ø  This magnetic force is produced by a coil which is excited by the electric current

Ø  Due to movable part it creates noise during operation

 

Solid-State Relay

Ø  This relay does not have mechanical contacts to control outputs

Ø  There are electrical switching elements such as Triac and MOSFET

Ø  Since no movable part is there so no noise it creates

 

Mechanical Relay- Advantages

Ø  It provides physical isolation between input and output

Ø  It can withstand higher voltages

Ø  These relays can tolerate short-term overload condition

Ø  Transients do not affect output of the relay significantly

 

Mechanical Relay- Disadvantages

Ø  Due to mechanical contacts its switching speed is slow

Ø  It has limited life span due to mechanical parts

Ø  These relays create contact-bounces which cause arcing

 

Solid State Relay - Advantages

Ø  It also provides physical isolation between input and output

Ø  Switching time is less as compared to the mechanical relay

Ø  Life expectancy is higher

Ø  These Relays offer greater reliability

Ø  No contact-bounce problems

 

Solid State Relay – Disadvantages

Ø  Resistance in the output circuit is normally higher as compared to an Electromechanical relay

Ø  It is not resilient to transient spikes and other overload conditions, like a mechanical relay, unless it is protected

Ø  A transient above the limits of the output device could destroy the solid state relay



 


Labels

Labels:

Comments

Post a Comment

Popular posts from this blog

How to Make Automatic Room Light Controller Without Microcontroller

You must have noticed in some offices or hotels, when nobody is in gallery or washroom, the light remains OFF but when somebody enters the place, light switches ON automatically. In this post I am going to teach you how to make this circuit. Before going ahead I would like to tell you that this is VERY EASY circuit. For this circuit the material we need is… PIR Motion sensor General Purpose PCB - 5x5 cm. Transistor 2222N – 1 No. Relay 5V – 1 No. 1K/0.250W – 2 Nos. 10K/0.250W – 1 No. IN4007 – 2 Nos. LED 3mm – 1 No. Connector – 4 Nos. Few wires. Relay Circuit Concept : We can use any relay of 12V, 24V, 5V etc. but we have to consider power supply or battery we will use. Since 5V power supply is easily available and 9V battery can also be used for 5V output (after using 7805 regulator if needed). So I am using 5V relay. PIR sensor has three terminals, One for 5Vdc Second for Gnd (0V). Third for ...
3 comments
Read more

Difference between Bootloader & Firmware Update

Updating the bootloader and updating the firmware in a microcontroller are two distinct processes, each serving different purposes and involving different steps. Here's a breakdown of the differences: Bootloader Update Purpose : The bootloader is a small program that runs before the main application. It is responsible for initializing the microcontroller and loading the main application firmware. Updating the bootloader might be necessary to add new features, fix bugs, or improve the boot process.   Process : 1.       Enter Bootloader Mode : To update the bootloader, the microcontroller must be put into a special mode. This often involves setting specific pins, pressing buttons, or using a specific command through an existing firmware interface. 2.      Communication Interface : The bootloader update typically uses a specific communication interface such as UART, SPI, I2C, or USB. 3.   ...
Post a Comment
Read more

AND Logic Gate by Transistors

Creating an AND gate using transistors is a fundamental exercise in digital electronics. In this post, I will guide you through the process of building an AND gate with transistors, explaining each step in detail.   What is an AND Gate? An AND gate is a basic digital logic gate that outputs TRUE or HIGH (1) only when all its inputs are true or high. If any of the inputs are false or low (0), the output is false or low (0). The truth table for a two-input AND gate is as follows: Input A Input B Output 0 0 0 0 1 0 1 0 0 1 1 1   Components Needed To build an AND gate, you will need the following components: NPN Transistors: BC547 (2 Nos.); Q1, Q2. Resistors : 10K (2 Nos) - R1, R2. Resistors : 1K (1 No) - R3. LED: 5mm Red (1 No) – L1, for output indication. Switches: ...
Post a Comment
Read more