What are the function and working principle of the copper braid in a latching relay?

A magnetic latching relay features two stable operating states: the reset state and the latched (working) state. Under normal conditions, it relies on a copper braid to facilitate stable current transmission, thereby ensuring electrical stability during state transitions. Upon leaving the factory, the device defaults to the reset state; in this configuration, the internal magnetic armature is held securely against one side of the C-shaped yoke, anchored solely by the magnetic flux generated by a permanent magnet. This maintains structural equilibrium and consumes no additional electrical energy-a fundamental basis for the device's energy-saving characteristics.

When the device requires switching to the working state, the transition is achieved by applying a voltage pulse to the "set" coil, leveraging the conductive properties of the latching relay's copper braid connector. Upon energization, the coil generates a directional magnetic flux that propagates rapidly along the yoke. By harnessing the interplay of attractive and repulsive forces between the bridge-shaped armature and the yoke, this flux displaces the armature, ultimately shifting the device into the latched working state. The entire switching process is characterized by rapid response, precise actuation, and zero superfluous energy consumption.

The core energy-saving advantage of the magnetic latching relay is most evident during the self-latching phase. Benefiting from the flexible conductivity of its flexible copper connector, the device maintains a stable state without inadvertent fluctuations. Once the armature has switched to the working position, the set coil can be immediately de-energized; continuous power supply is no longer required to sustain the operating condition. Instead, the device remains locked in the working state indefinitely, sustained solely by the residual magnetic flux retained within the yoke by the permanent magnet. This effectively resolves the critical drawbacks associated with traditional relays-specifically, the issues of excessive heat generation and high energy consumption resulting from prolonged energization.

The principle behind the device's reset operation is the inverse of the setting process. By leveraging the high conductivity and low resistance properties of a pure copper braid, the device ensures the stable generation of a reverse magnetic flux. By applying a voltage pulse to the "reset" coil, the yoke generates a magnetic flux directed in the exact opposite direction to that of the setting phase. Through the interplay of these opposing magnetic repulsive and attractive forces, the armature is driven back to its initial reset position, thereby completing a full operational switching cycle.

Compared to conventional relays, the magnetic latching relay offers distinct advantages in terms of shock resistance; when paired with a bare copper braid, it further enhances the overall structural integrity and operational stability of the device. Whether in the set or reset state, the device relies on a permanent magnet latching mechanism to maintain its structural configuration. Under both operating conditions, force distribution is uniform and stability is consistent; furthermore, the device exhibits excellent resistance to shock and vibration, making it well-suited for long-term operation in both complex industrial environments and residential electrical applications.

Based on their internal coil structure, magnetic latching relays can be categorized into two types: single-coil and dual-coil configurations, thereby accommodating the diverse assembly requirements associated with copper braids for latching relays. Single-coil relays achieve state switching-between set and reset-by reversing the voltage polarity, offering a streamlined structural design. Dual-coil relays, conversely, execute state transitions by applying a preset voltage to specific terminals. Each structural type is suited to distinct application scenarios, enabling them to satisfy a wide range of circuit design requirements.