Overview

The WG631 is a zero-power magnetic sensor developed by Nanjing AH Electronic Science & Technology Co., Ltd. It operates without an external power supply by utilizing the Wiegand effect to generate sharp voltage pulse signals. The sensor is composed of a specially processed alloy wire with dual magnetic properties, an induction coil, and a frame lead.

Key Features

• No external power required during operation.
• Operates with a dual magnetic pole excitation method, producing a pair of positive and negative electrical pulse signals per magnetic polarity cycle.
• Outputs pulses only when the external magnetic field polarity changes and the magnetic induction strength reaches the excitation threshold, ensuring stable and reliable operation without signal jitter.
• Pulse amplitude is independent of the magnetic field change speed, enabling operation at near-zero speeds.
• Output signals can be transmitted over long distances via signal lines, suitable for local area network management.
• No mechanical contacts or electric sparks, making it an intrinsically safe device.
• Wide operating temperature range and strong environmental adaptability.

Operating Principle

The WG631 sensor exploits the Wiegand effect, where the alloy wire's inner core (soft magnetic) and outer shell (hard magnetic) have different magnetic properties. Under an alternating magnetic field of sufficient strength, the inner core's magnetization direction flips rapidly, causing a sudden change in the surrounding magnetic field. This induces a pair of positive and negative voltage pulses in the coil. The pulse amplitude depends solely on the excitation magnetic field strength and not on the rate of magnetic field change, allowing zero-speed counting detection.

Technical Specifications

Physical Characteristics

The sensor uses tin-plated copper hard leads with no polarity distinction on the pins. The product marking is an ink stamp labeled "WG631".

Critical Information and Best Practices

• Ensure the external magnetic field polarity changes and reaches the excitation threshold to generate output pulses.
• The sensor is suitable for environments requiring intrinsic safety due to the absence of mechanical contacts and sparks.
• Its stable output at near-zero speeds makes it ideal for precise counting and detection applications.
• Wide temperature tolerance allows use in harsh environmental conditions.