Enhancing energy efficiency in modern electrical systems: a dive into contactors and relays

This article originally appeared in the October'24 magazine issue of Electronic Specifier Design – see ES's Magazine Archives for more featured publications

By Carlos Mendes, Product Manager for Switching, Durakool

These components, while small in stature, play a monumental role in the functionality and efficiency of modern electronics. Carlos Mendes at Durakool sheds light on these critical components and their contributions to energy efficiency.

Understanding the basics

Contactors and relays are electromagnetic switches used for controlling the flow of electricity in various applications. In simple terms, they allow the electrical system to turn on or off the power supply to different parts of a device or a vehicle. This basic functionality is vital in ensuring the safety and efficiency of electronic devices and vehicles.

One of the primary functions of these components is to manage high currents and voltages. However, this often necessitates large coils, which can draw significant amounts of power. In electric vehicles (EVs), for instance, the contactors are engaged as long as the vehicle is in motion, maintaining safety by disconnecting the battery during malfunctions or accidents. But this can also mean a constant drain on the battery, potentially reducing the vehicle's range.

Innovations in energy efficiency

Durakool has pioneered several solutions to enhance the energy efficiency of these essential components. Our approach focuses on reducing power consumption while maintaining the reliability and functionality of the contactors and relays. Two key technologies we employ are the PWM economiser and the twin coil economiser.

The PWM Economiser, PWM stands for Pulse Width Modulation, reduces the power used by the coil by approximately 50%. By modulating the width of the electrical pulse, we can maintain the coil's operation while consuming less power. This reduction is crucial for extending the life of the battery in electric vehicles, as it reduces unnecessary energy expenditure.

The Twin Coil Economiser is a solution that involves two coils – a larger coil to initiate the switching process and a smaller one to maintain the operation. The twin coil system allows for a significant reduction in power consumption, especially when the system is energised for extended periods, such as during long motorway drives. By using these economisers, the energy efficiency of the contactors is significantly enhanced, benefiting both the end user and the environment.

The role of sensitive coils

Beyond economisers, we also offer sensitive coil technology. Sensitive coils have higher resistance, meaning they require less current to achieve the same switching capability. This is particularly advantageous in printed circuit board relays, where space and power  consumption are critical considerations.

In practical terms, this means that our relays draw less current, contributing to overall energy savings. For users, whether in industrial settings or consumer electronics, this translates to reduced operational costs and a smaller environmental footprint.

Material innovations in contact design

Another area to consider is the materials used for contact tips. The choice of material can significantly affect the efficiency and longevity of the contactors. Different materials have varying resistance levels and can handle different amounts of current and voltage.

For instance, if a relay is in the closed position for extended periods, there is a resistance between the contact points, leading to heat generation. This heat is wasted energy. Therefore, selecting materials with low resistance can mitigate this issue – for example, silver nickel for low-resistance scenarios and silver tin oxide for high-resistance needs.

Moreover, we use a special material, silver tin oxide indium oxide (AgSnOInO), which is highly effective at resisting welding in contacts. This innovation is crucial for applications with frequent switching, such as in electric motors. By preventing contact welding, we ensure the reliability and safety of our products, which is particularly important in critical applications.

Real-world impact

To illustrate the real-world impact of these innovations, consider the case of caravan movers. These devices, which are used to move caravans without a towing vehicle, rely heavily on relays. A common issue faced by manufacturers was the welding of relays due to the wrong choice of contact material. By using our specialised contact material, we were able to resolve this problem, ensuring smooth operation and enhancing customer satisfaction.

In industrial settings, such as construction vehicles and forklifts, the need for reliable and efficient electrical systems is vital. The reduced power consumption not only extends battery life but also aligns with the growing demand for sustainable solutions in heavy-duty applications.

Looking ahead: the future of energy efficiency

The drive towards energy efficiency is not just a trend but a necessity in the face of global environmental challenges. We need to continue advancing our technologies and expanding their applications across various industries. Our focus on reducing power consumption, enhancing the reliability of electrical systems, and utilising innovative materials positions us as leaders in this field.

We are exploring applications beyond vehicles, such as renewable energy systems. In solar and wind energy installations, the ability to efficiently manage power consumption is crucial. Our technologies can play a significant role in these sectors, providing energy-conscious solutions that benefit both consumers and the planet.

The journey towards energy efficiency in electrical systems is complex but rewarding. Through innovation, strategic material choices, and a commitment to sustainability, we want to help drive change and set new standards in the industry. Our contactors and relays are more than just components; they are vital contributors to a more sustainable  and energy-efficient future.