Discover our globally certified range of industrial accessories, manufactured with German technology and rigorous ISO 9001:2015 specifications.
In the modern era of smart grids, electric vehicles (EV), and high-efficiency HVAC control boards, the demand for bi-stable latching relays has experienced exponential growth. Unlike monostable relays that require continuous power supply to maintain their switching state, latching relays rely on short electrical pulses to transition. Permanent magnets hold the contacts in place. This mechanism ensures zero coil power consumption during continuous operation, significantly lowering thermal emission, reducing parasitic load, and driving down global carbon footprints.
As the global power infrastructure transitions toward decentralized energy management systems and high-current smart meters, latching relays must fulfill strict standards like UC2 (100A) and UC3 (120A) switching capacities under IEC 62055-31. Today's manufacturing demand has shifted toward suppliers who can integrate precision copper terminals, smart control PCBs, and custom casing geometries, bridging mechanical perfection with smart electronic command systems.
Ningbo Taojun Refrigeration Equipment Co., Ltd. is situated in Xiangshan, Ningbo, a prominent center for advanced industrial manufacturing. Founded in 1988, its predecessor was the Xiangshan Refrigeration Accessories Factory of Zhejiang University. For over 30 years, we have integrated technological innovation, scientific research collaboration, and precise metallurgy to engineer world-class solutions.
As a recognized national high-tech enterprise, we hold prestigious certifications including ISO 9001:2008, ISO 9001:2015, EU RoHS, and UL certification. Through collaborative engineering efforts with the University of Science and Technology of China, our research division has pioneered energy-efficient controls, electronic PCB modules, frequency air conditioner inverter systems, and copper filtration networks.
Analyzing the electrical design architecture and materials engineering that define next-generation latching relay switches.
By refining the spatial configuration of the permanent magnet and high-permeability iron core, we minimize magnetic leakage. This allows the relay to switch state with a pulse as short as 15 milliseconds, minimizing power supply capacitor requirements on control boards.
Using silver tin oxide (AgSnO₂) contacts provides superior material migration resistance, preventing contact welding during high capacitive and inductive inrush currents. Ideal for EV charging, LED switching loads, and smart grid applications.
Utilizing high-purity oxygen-free copper shunts lowers contact resistance down to less than 0.8mΩ. Minimizing internal heating ensures structural reliability even when carrying continuous loads up to 120A, satisfying UL thermal guidelines.
| Parameter Class | Monostable Relay | Single-Coil Latching Relay | Dual-Coil Latching Relay | |
|---|---|---|---|---|
| Coil Power Consumption | Continuous (Typically 0.5W - 2W) | Pulse Drive Only (Zero Static) | Pulse Drive Only (Zero Static) | |
| Operating Temperature Rise | Moderate to High (Coil generates continuous heat) | Negligible (Only contact resistance drop) | Negligible (Only contact resistance drop) | |
| Control Command Method | Continuous Voltage Level Control | Single positive/negative voltage pulse | Independent SET and RESET pulses | Set/Reset pulse commands |
| Inrush Current Resistance | Standard (Up to 50A peak) | Excellent (Up to 3000A for 10ms with AgSnO₂) | Outstanding (Optimized for UC3 smart meters) |
Decades of continuous process improvement, rigorous material sourcing, and specialized engineering partnerships.
Core automated tooling and manufacturing assets are imported directly from Germany, ensuring sub-micron manufacturing tolerances for metal parts and critical assembly paths.
Our R&D center retains 15 specialized engineers, including doctors and professors from the University of Science and Technology of China, focusing on magnetic circuit dynamics and smart materials.
We secure advanced materials from world-class suppliers, including Japanese high-stability spacer materials, certified high-temp protection foils, and European custom formulation polymer housings.
Every control board assembly and relay configuration undergoes 500 hours of thermal cycling stress tests (-35°C to 75°C), high-voltage isolation checks (100V and above), and rigorous mechanical endurance runtimes.
We work directly with major appliance OEMs (Haier, Midea, Whirlpool, Electrolux) to design and configure smart controller PCBs, specialized terminals, and high-reliability switching arrays.
We deploy MES real-time intelligent workshop management, CCD high-speed visual defect inspections, and helium mass spectrometer leak testing systems to maintain our low defect margin of 0.05%.
At Taojun, we specialize in heavy-duty commercial and consumer refrigeration components alongside robust micro-controller switching assemblies. Our copper filter driers are designed to absorb moisture and acid, filtering out impurities to protect the compressor. Normally installed as critical components, they are integrated globally in household appliances and commercial cooling grids.
Deploying energy-efficient switching technology and thermal management across global infrastructure networks.
Integrated in smart prepaid electricity meters to execute remote connect and disconnect commands. Compliant with anti-tampering designs and high-surge short-circuit current withstand capabilities.
Embedded directly into inverter HVAC control boards, working alongside capacitors and filter driers to power up high-capacity fan motors and cycle refrigerant valves safely.
Enables high-efficiency smart EV chargers and smart outlets to handle frequent high-current relay operations safely with minimal thermal wear and negligible standby power consumption.
Ningbo Taojun's evolution is built on thirty years of continuous exploration. Moving from a regional manufacturer to a national high-tech enterprise, we believe that an internationally respected brand is sustained by a robust corporate culture.
Established as the Xiangshan Refrigeration Accessories Factory of Zhejiang University, setting the engineering foundation.
Expanded physical factory infrastructure, increasing mass production capacity of copper components.
Implemented MES intelligent workshop management, integrating digital production dispatching and material tracking.
Created the specialized "Taojun" refrigeration condenser, valve line, and electronic smart device divisions.
Recognized as a national high-tech enterprise. Standardized clean room facilities and automated welding lines.
Taojun Factory Operations & Historic Facilities
Taojun MES Smart Manufacturing Operations 2024
Adhering to people-oriented integrity management, prioritizing premium reputations as a competitive edge.
Permanently adjusting technologies and concepts to capture emerging technological trends.
Sustaining a strong commitment to green manufacturing and smart grid energy conservation.
Striving to build mutual integrations of resources to create win-win manufacturing outcomes.
For procurement officers and international OEM partners, certification transparency is vital. Ningbo Taojun operates under formal registration for design, development, and production of precision refrigeration components, control boards, and access valves. Our official registration number GB/T19001-2016 / ISO9001:2015 is validated through CNCA and international accreditation bodies.
This framework guarantees that raw material tracking, inspection of incoming parts, and final assembly lines follow precise procedures, keeping batch-to-batch variation minimal.
Quality Management Registration Certificate
Scope Certification & CNCA Accreditation
Answering major engineering and integration questions about latching relays and intelligent controllers.
Latching relays are bi-stable, meaning they only require energy (a voltage pulse) to switch their state. Once switched, a permanent magnet keeps the armature stable, consuming no power in the active state. This design minimizes grid power loss and reduces heat inside sealed smart meters, preventing thermal drift in precision current sensors.
A single-coil latching relay utilizes polarity reversal of a single coil to switch back and forth. A dual-coil latching relay utilizes two distinct coils, one for setting and one for resetting. Dual-coil configurations simplify driver circuitry in control microprocessors, as positive pulses are routed to separate input lines rather than requiring an H-bridge controller.
Ohmic heating is calculated as P = I²R. If contact resistance is high, carrying a continuous 100A load can generate excessive thermal energy, which can cause housing deformation or weld the relay contacts. We use high-purity copper terminal blocks and silver tin oxide contacts to keep contact resistance below 0.8mΩ, helping maintain safe operating temperatures.
We configure silver tin oxide (AgSnO₂) contacts, which feature high thermal stability and resist micro-arcing. During layout, our design optimization reduces mechanical contact bounce to less than 2 milliseconds. This reduces short-duration arcing during high-load powerups.
For global compliance, relays must meet EU RoHS and REACH limits to verify they are free of lead and heavy metals. Electrically, smart meter integrations require compliance with IEC 62055-31 (UC2/UC3 standards) for high-fault short circuit capabilities, alongside UL standards for fire safety.
High-quality components manufactured to international industry and environmental standards.
Taojun