What Is a Wireless Control Relay?
A wireless control relay is a relay device that receives electrical signals and outputs digital signals to control machinery, using wireless communication methods such as Bluetooth.
Control relays receive external electrical signals and perform tasks like turning electrical circuits on/off or switching them. They relay input signals from sensors or push buttons to other devices. Communication methods vary by product, including Wi-Fi, Bluetooth, and sub-GHz band wireless. These relays are used in various industrial scenarios where wired installation is difficult or in coordination with wireless sensors.
Uses of Wireless Control Relays
Overview
Wireless control relays are used to receive signals wirelessly from sensors and push-button switches and control other devices or processes wirelessly. Specific applications include:
- Controlling industrial processes in conjunction with wireless temperature or pressure sensors
- Smart home automation
- Eliminating wiring in manufacturing and conveyance processes in factories
Applications in Manufacturing
In manufacturing, wireless control relays are used with sensors and switches in the following ways:
- Efficient transmission of trouble alerts
- Efficient reporting of task completion
- Switching the direction of conveyor belts
- Wire-free layouts allowing flexible layout changes
- Remote operation of forklift communication and shutter control
- Counting inspection results and distinguishing between good and defective products
- Activating AGVs (Automated Guided Vehicles) for parts transport
- Indicating vehicle entry and exit
Principle of Wireless Control Relays
Overview and Wireless Communication
A relay is a component that receives external electrical signals and controls the on/off or switching of electrical circuits. Wireless control relays use various wireless communication methods, such as Wi-Fi, low-power radio, Lora, LoRaWAN, and Bluetooth, for communication with sensors and target devices. The suitable data communication method is selected based on the product and application. For example, LoRaWAN offers excellent reception sensitivity and resistance to radio interference, enabling communication distances of over 10 km in ideal environments, making it suitable for wide-area operations.
Wireless control relays, like traditional relays, come in two types: mechanical contact relays and solid-state relays.
Mechanical Contact Relays
Mechanical contact relays operate by mechanically moving contacts to output a contact signal. They are composed of components like electromagnetic coils and contacts and are also known as electromechanical relays due to their operating principle.
When an input voltage signal is received, the internal electromagnetic coil is energized, acting as an electromagnet and moving the movable contact with the movable iron piece. The movable contact touches or separates from the fixed contact, outputting an electrical contact signal.
Solid-State Relays
Solid-state relays have no mechanical moving parts like contact relays and are composed of semiconductors and electronic components like triacs and MOSFETs. They electronically switch signals or currents/voltages on and off using these electronic circuits.
Types of Wireless Control Relays
Wireless control relays come in various types. In addition to the operational mechanisms of contact and solid-state relays, there are different types of contact configurations and output methods. The types of contacts include:
- Form A (Normally Open) Contact: Activated by the input signal
- Form B (Normally Closed) Contact: Deactivated by the input signal
- Form C (Transfer) Contact: Combines Form A and Form B, with each operating inversely to the input signal
Functionally, there are products designed to work with wireless pressure sensors or temperature sensors, products with integrated push-button switches, and products intended for smart home applications. The hardware aspects, such as operating temperature, vary by product. Products with an IP54 waterproof rating, for example, can be used in wet environments or outdoors.