If you’re working on an electronics project, you might want your circuit to open/close based on your inputs. To do so, you can take help of a relay module, but that’s not such a straightforward task. Therefore, in this article, you’ll learn about a relay module, and how it serves as one of the most important parts in an electronics gadget. You’ll also get a brief understanding on how to use a relay module in an arduino project.
What’s a relay module?
A relay module acts like a switch to your electronic circuit that lets users open or close it by transmitting a signal. You can attach a relay module to your circuit’s power pins. When an electronic signal is received by the relay module, it’ll open/close the circuit according to the signal. You can attach buttons for opening and closing the circuit to the relay module.
Think of an example of a radio-controlled toy car, where the car propels only when you press the button on your wireless remote. The remote transmits electronic signals that the relay module in the toy car catches. It allows current to pass to the toy car’s circuit only when the button on the remote stays pressed.
What are the functions of a relay module?
- Switching High Power
Relay modules can help microcontrollers or other low-voltage components on the circuit board to control the circuit’s on/off state based on the user’s input. A relay module can handle high power voltage that isn’t possible for low-voltage ICs in the PCBA. - Signal Amplification
If your PCBA is getting low voltage signals that you need to amplify to high voltage, then you can implement a relay module to your PCBA. A relay module can amplify weak signals to high voltage due to mechanical movements in it.
Also read: What should be noticed in high voltage PCBs installation?
Different types of relay modules
- Electromechanical Relay Modules
These relay modules have electromechanical relays that are one of the initial relay technologies. You can expect fair reliability from them and you can use them in home automation systems, industrial control systems, and other general-purpose applications. - Solid-state Relays
These relay modules don’t have any movable components inside them as you’ll find solid-state relays inside them. They can control the switching process through thyristors or MOSFETs. If you need a relay module with a silent operation, fast switching, and durability, then this one is the best choice. - Time Delay Relay Modules
When you want your project to be time controlled, i.e., when the current switching should be based on a timer, then this module comes into action. It has a built-in timer function that allows programmers to set the on/off duration and time.
What are the applications of the relay module?
1.Automation in industries and homes: You can think of any home automation gadget like curtains, washing machines, IoT devices, etc., they all rely on relay modules. Industries with fully automatic machines and plants have relay modules.
2.Robots: You’ll hardly find any modern robot without a relay module in it.
3.HVAC systems: Think of any fan, compressor, air conditioning system, etc. They’re all equipped with a relay module.
4.Energy management systems: Some energy management systems that have relay modules include solar panel systems, generators, etc.
5.Security systems: There are several surveillance systems, alarms, and access control devices that have relay modules inside them.
Also read: What is energy storage BMS
How does a relay module function?
1.Coil Activation
There’s an electromagnetic coil in the relay module. When the microcontroller sends electric signals to the relay module, the electromagnetic coil activates and generates an electromagnet field.
2.Armature Movement
There’s a movable armature in the relay module that gets into motion when the electromagnetic field reaches it.
3.Contacts Switching
The armature moves and reaches a contact. The contact gets closed, letting current pass through the relay module. When the coil stops generating electromagnetic field, the armature moves back to its initial position, away from the contacts, which opens the contacts, stopping the current flow immediately.
Relay Module VS Relay : What are the differences?
Comparison Basis | Relay | Relay Module |
Design Integrity | Standalone device with a coil, armature, and contacts. It needs to be wired manually | Offers a complete ready-to-use module for switching applications |
Mounting & wiring | Needs a lot of mounting and wiring | It’s easy to use as there’s a standard mounting and wiring needed |
Control signal compatibility | The voltage applied to the relay must match the coil’s specifications | A relay module can accept a range of voltages and current |
Compactness & space efficiency | Less compact and space efficient | They’re compact and space efficient |
Additional features | Doesn’t house additional features | It houses additional features like indicator LEDs, transient protection, snubber circuits, and more |
How to use relay modules in Arduino?
1.Gather all the materials that you’ll need in the project. In a nutshell, you’ll need an arduino board, relay module, jumper wires, power supply, and the circuit board that you’ll control using your relay module.
2.Connect the power supply and set up the project. Then connect the control pins. Finally connect the load (circuit board that you’ll control using a relay module).
3.Power up your arduino using a power supply or USB cable.
4.Write the code. One code example is as follows:
// Define the Arduino pin connected to the relay module control pin
const int relayControlPin = 2;
void setup() {
// Set the relay control pin as an output
pinMode(relayControlPin, OUTPUT);
}
void loop() {
// Activate the relay
digitalWrite(relayControlPin, HIGH);
delay(1000); // Wait for 1 second
// Deactivate the relay
digitalWrite(relayControlPin, LOW);
delay(1000); // Wait for 1 second
}
5.Upload your code and run it. The code will be compiled and uploaded to your arduino board by your IDE.
What factors are affecting a relay module’s price?
The price of a relay module depends on these factors:
1.Features: A simple relay module will be cheaper than those with added additional features like LED indicators, etc.
2.Mounting and form factor: Relay modules might have PCB mounting, DIN rail, etc. that act as the reasons for added cost.
3.Current and voltage: While relay modules have a range of voltage and current, if you’re looking for a relay module with a specific current and voltage to match your application, you might have to pay a little more.
4.Additional costs: Sometimes, the cost of a relay module highly depends on the shipping fees, custom duties (if any), brand, order quantity, taxes, etc.
Final Verdict
After learning about relay modules, you’re sure to get started with using a relay module in your project. If you don’t want to risk it, you can contact IBE Electronics, who’ll make sure that the right type of relay module gets used in your PCBA project. IBE Electronics will handle all the odds that could cause complexities in your relay module-based project.
1.Coil Activation
2.Armature Movement
3.Contacts Switching
1.Automation in industries and homes
2.Robots
3.HVAC systems
4.Energy management systems
5.Security systems
1.Features: A simple relay module will be cheaper than those with added additional features like LED indicators, etc.
2.Mounting and form factor: Relay modules might have PCB mounting, DIN rail, etc. that act as the reasons for added cost.
3.Current and voltage: While relay modules have a range of voltage and current, if you’re looking for a relay module with a specific current and voltage to match your application, you might have to pay a little more.
4.Additional costs: Sometimes, the cost of a relay module highly depends on the shipping fees, custom duties (if any), brand, order quantity, taxes, etc.
