Hamectrol, a 100% subsidiary of the PKTRONICS group, represents and markets the products of the proximity sensor range of the company LITTELFUSE, Ex-HAMLIN.
Proximity sensors and reed switches (or reed switch, also called ILS, flexible reed switch) are the most common and most economical solution for non-contact object detection. There are several types of proximity sensors that are used depending on the need and material detection. The REED bulb is the basic component of magnetic sensors. The main advantages are :
- No power supply required. No current consumption in the open state with real galvanic isolation and no voltage drop in the closed state.
- Operates in difficult environments: wide temperature range, insensitive to dust, water projections, etc.
- Detection distances can be very large. They will depend essentially on the magnetic sensitivity of the bulb and the power of the magnet as well as the magnetic environment of the Reed Switch + Magnet couple.
- Very economical compared to all other technologies.
Littelfuse offers REED bulbs (or switches) which are used as switching elements in magnetic proximity sensors and reed relays. REED switches have been irreplaceable for more than 50 years, and every year new applications integrate them, for their simplicity of operation, their price, their small size and their reliability.
A bare reed switch can easily be mounted on printed circuit boards. However, for an application such as a door safety sensor, the reed switch needs a protective housing to be handled and mounted. These housings provide resistance to mechanical stress by protecting the bare glass of the reed switch.
There are several considerations when integrating a reed switch into a housing, such as damage to the reed switch due to mechanical shock and change in sensitivity due to mechanical stress. Depending on the type of mechanical shock, damage can take the form of loss of the hermetic seal, a change in sensitivity, or failure to operate due to the breakage of the glass capsule. We have extensive expertise in custom reed sensors as well as standard sensors with high levels of quality and reliability.
Concerning the choice of reed sensors and switches there are several parameters to be taken into account, such as the electrical switching load, activation methods, etc. Since a reed sensor is a magnetic sensor, ferromagnetic materials such as steel in the vicinity of the sensor can influence its behavior. Motors, transformers and other high-current electrical devices near the reed sensor can also cause an undesirable influence. Another influence to be aware of is temperature. Magnets and reed sensors become more magnetic at low temperatures and less magnetic at high temperatures. The changes due to temperature depend on the type of magnet and reed switch used.
Sensor housings can be made of plastic or stainless steel. Mounting can be done with screws or by soldering on a printed circuit board. The sensors can be placed in a hole and held in place with nuts (threaded sensors) or with retaining clips (cylindrical sensors). Although we offer a wide variety of standard products, they cannot be adapted to every application. This is why Hamectrol works closely with its customers to provide customized solutions, integrating other components to make the sensors smart and offering specific housings.
In automation applications, “all-or-nothing” sensors have not become commonplace: obstacle detection, limit switches, etc. Although they often go unnoticed, these components perform essential functions.
One of the flagship applications for these products is home automation, which uses technologies such as the Internet of Things (IOT), the Industrial Internet of Things and connected objects to improve the quality of life and the performance of services and certain equipment. These components are highly valued by start-up companies because of their ease of implementation, and are highlighted in their business models. Most hardware used in home automation consists of connected sensors that measure various parameters and transmit the information to a central station that uses an IP network to relay the data to a smartphone, PC or other mobile device.
The advantages of reed sensors are important for use in devices connected to the Internet, but also for big data. They do not require power for operation and can withstand high loads without the need for amplification circuits. They are hermetically sealed and can be used in humid or even explosive environments ranging from -40°C to 125°C. They are immune to electrostatic discharges and are available to detect a wide range of distances, levels or speeds. These sensors can therefore play a key role when implemented in Industry 4.0 applications, ensuring the best possible data collection experience.