IoT-Enabling Power Supplies for Critical and Industrial Environments

Introduction

Industrial environments need reliable, efficient, and robust power for reliable, uninterrupted performance of their Internet of Things (IoT) system applications. Unfortunately, IoT systems often face unpredictable power conditions that standard power supplies struggle to manage. This article discusses how CUI’s IoT-enabling VOF-4 Series power supplies can provide reliable power for industrial IoT applications.

What is an IoT-Enabling Power Supply?

An IoT-enabling power supply is a device that supplies the necessary electrical power for IoT device operation. Many IoT devices, including sensors, processors, communication modules, and smart appliances, require constant connectivity to transmit data while consuming minimal energy. IoT-enabling power supplies are engineered to deliver energy efficiently and reliably, which is crucial for devices that frequently switch between standby and active modes. Unlike conventional power supplies in homes or offices, these specialized power supplies are engineered to handle a wide range of input voltages and sudden voltage fluctuations while operating reliably in harsh environments such as high temperatures, high altitudes, and strong electromagnetic interference (EMI).

Characteristics of Power in Industrial Settings and Common Power Quality Challenges

Even the best industrial power distribution systems are vulnerable to sudden changes in system voltage. These can negatively impact the performance and longevity of finely tuned electronic equipment by inducing harmonic distortion into electrical networks, precipitating power quality concerns, and adversely affecting other interconnected devices. The common types of power quality concerns include:

• Voltage fluctuation (sags & swells): Voltage sags and swells severely impact IoT devices by disrupting sensor accuracy and causing communication failures. This can lead to microcontroller malfunctions, such as brownout resets and data corruption. They destabilize power management circuits, forcing regulators into dropout mode during sags or causing overheating in components during swells. Additionally, battery charging systems in portable devices may fail. Continuous problems can degrade uptime and damage sensitive components, such as capacitors and semiconductors, through thermal runaway or dielectric breakdown.
• Transients (surges & spikes): Transients can threaten the operational integrity of IoT systems in critical environments. They can damage semiconductors and destroy IoT devices. High-energy spikes disrupt microprocessors' and memory subsystems' clock signals, logic levels, and timing mechanisms. Since transients can introduce EMI, they can affect communication interfaces such as Ethernet, Wi-Fi, or serial buses (e.g., I2C, SPI), leading to communication failures.
• Harmonic distortions: Many IoT devices use switch-mode power supplies (SMPS) to control voltage. However, harmonic distortion causes switching losses and reduces the efficiency and lifespan of power supplies, disrupting communication protocols like Wi-Fi and Zigbee. Due to the input current power losses of transformers and capacitors in the form of heat, such disruption can cause packet loss and unreliable data transfer. Moreover, voltage ripple disrupts microcontroller operation and introduces noise that can distort sensor data in time-critical IoT applications. For battery-powered devices, harmonics reduce charging efficiency and shorten battery life.
• Low power factor: A low power factor in IoT systems increases current draw, causing energy losses and straining infrastructure, leading to poor device performance, higher costs, and limited scalability for IoT projects.

The CUI VOF-4 Series: A Power Solution for Industrial IoT Applications

The VOF-4-12 from CUI is an internal open-frame AC-DC power supply from the VOF-4 series. Designed to fit within a compact 2" x 1" board mount, it features no-load power consumption of less than 0.075 W, a wide operating temperature, and an efficiency of up to 82%. This unit is built to provide reliable energy for industrial IoT applications, even in critical environments. The CUI VOF-4-12 can operate normally at altitudes up to 5,000 meters.

The key features include:

• Wide input voltage range: Designed to handle universal input voltages (85–305VAC), ensuring stable operation in regions with power-quality irregularities.
• Robust output: Provides 12V at 0.333A, making it suitable for powering sensors, microcontrollers, and communication modules integral to IoT systems.
• Efficiency and reliability: An efficiency rating of up to 82% minimizes energy loss, critical for reducing operational costs in large-scale deployments.

• Designed for extreme environmental conditions: Operates reliably at altitudes up to 5,000m and within a wide temperature range of -40 to +80°C, ensuring dependable performance in diverse and extreme industrial settings.
• Low no-load power consumption: When idle, it consumes less than 0.075W, which helps to enhance energy efficiency for IoT systems.
• Comprehensive protection: It features a built-in TVS component and includes short circuits, overvoltage, auto-recovery, and hiccup mode protections, ensuring enhanced durability. It is designed to operate in environments classified under Overvoltage Categories (OVC) II and III.
• Compact design: Housed in a space-saving 2" x 1" chassis mount, making it suitable for integration into space-constrained applications.
• Certified Safety Standards: Compliant with 62368-1: EN/UL, ensuring adherence to industrial safety requirements.

The VOF-4-12 belongs to the VOF-4 series, including models like the VOF-4-3, VOF-4-5, VOF-4-15, and VOF-4-24 (See Related Feature products). Each model offers a different output voltage, catering to various application needs.

How to Select an IoT-Enabling Power Supply

Choosing the correct power supply for an IIoT system depends on balancing performance, reliability, and environmental compatibility. Here are the key factors to consider in the selection process:

• Input voltage specifications: When selecting an IoT-enabled power supply, ensure the input voltage range of the supply complies with all application requirements and global standards for reliable performance. A standardized range of 85–264 VAC supports worldwide variations, accommodating a 15% drop on 100 VAC systems and a 10% margin above 240 VAC for regions such as the US, Canada, and the UK. For industrial applications using 277 VAC from 480 VAC Wye configurations, power supplies rated up to 305 VAC can easily handle fluctuations. Additionally, ensure the supply supports a range typically 1.4 times the AC rating for DC input setups. These specifications are crucial for stable operation in diverse environments and configurations, which is critical for IoT systems.
• DC output voltage requirements: A wide selection of standard supplies is available for common output voltages such as 5, 12, 24, or 48 VDC. The DC output voltage should match the system's needs for compatibility and efficiency.
• Size and form factor: The package design and mounting style must align with the device's size, integration needs, and operating environment. Options such as potted, open frame, U-frame, enclosed, and fan-cooled designs offer varying levels of protection against contaminants. Mechanical setup and space constraints determine mounting styles, including PCB, chassis, or DIN rail.
• Power output and current rating: Match the output power or load current to the device's peak demand. Using oversized power supplies can lead to extra costs and wasted space, while undersized ones can cause shutdowns or voltage problems during peak usage. Power supplies designed for short peak power bursts offer an efficient and cost-effective solution for applications that occasionally need high power.
• Environmental operating conditions: Environmental conditions are critical in selecting IoT-enabled power supplies. Power supplies must account for derating at extreme temperatures (see Figure 3), where cold reduces capacitor efficiency and limits output current, while high heat impacts component performance and power delivery. For higher temperature environments, forced air cooling can increase output capacity.

• Safety and compliance certifications: Safety and compliance certifications are critical when selecting IoT-enabled power supplies to meet regulatory requirements for specific applications, such as IEC 60601 for medical, IEC 60335 for household appliances, and IEC 62368 for ICT devices. Safety and operational standard certifications such as UL, TUV, IEC, and EN ensure the power supply guarantee reliable, compliant performance in the final system and facilitate product approvals.

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Conclusion

As industrial environments often face unique challenges with power stability, IoT-enabling power supplies are essential for ensuring uptime and optimal performance. The VOF-4-12 power supply from CUI illustrates how robust design features effectively address these challenges, providing a dependable energy source

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VOF-4-12 AC/DC Open Frame Power Supply (PSU), Chassis Mount, ITE & Industrial, 1 Output, 4 W Buy now

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About the Sponsor

CUI Inc is a Bel group company (NASDAQ: BELFA and BELFB). Bel designs, manufactures and markets a broad array of products that include circuit protection, connectors, cable assemblies, discrete components, magnetics and power supplies. The company serves a global market and operates facilities around the world. For more information, click here