Introduction

The north pole and south pole are the only existing polarities when it comes to a magnet. From the basic knowledge, unlike poles that the north and south poles attract, poles of the same polarity repel each other. Therefore, determining which is the north and south poles is quite tricky, hence the need for a simple magnetic polarity detector. Magnet Polarity Sensor Circuits are created using Hall effect sensors. Hall effect sensors find extensive utility in multiple fields, such as robotics, automotive technology, and consumer electronics, where they are employed to identify the existence of a magnetic field and ascertain its polarity. These sensors operate on the Hall effect principle, which generates a voltage differential across an electrical conductor within the Hall effect sensor when a magnetic field is introduced perpendicular to the current's direction.

Necessary Components

• RED LED Light emitting diode, small symbol D1 LED_0402_1005Metric
• BLUE LED Light emitting diode, small symbol D2 LED_0402_1005Metric
• Screw_Terminal_01x02 Generic screw terminal, single row, 01x02, script generated (kicad-library-utils/schlub/autogen/connector/) J1 TE_282834-2
• SW_Push_Dual_x2 Push button switch, generic, separate symbols, four pins SW1 SW_DIP_SPSTx01_Slide_6.7x4.1mm_W6.73mm_P2.54mm_LowProfile_JPin A1365xKTTN-10 Programmable Linear Hall Effect Sensor, +6.4 to +14mV/G, SIP-4 U1 Allegro_SIP-4

Magnet Polarity Sensor Circuit

This circuit is assembled using readily accessible components, with the core element being the APX9141 Hall Effect sensor. The sensor incorporates a Hall element and offers two distinct outputs labeled DO and DOB, which are instrumental for identifying the poles of a magnet. In this configuration, a Red LED is linked to the DO output (pin 2), signifying the North pole, while a Blue LED is attached to the DOB output (pin 3), symbolizing the South pole. This sensor functions optimally at 3 volts, so a CR2032 3V cell is integrated to supply the necessary bias voltage.

Magnet Polarity Detector Circuit PCB

The APX9141

It has four pins, including PIN1, the VDD; PIN2, the DO; PIN3, the DOB; and PIN4, the GND.

Features of the APX9141

• 4 pin TO-92M package
• Integrated Reverse Voltage Protection on the chip
• Embedded Hall Sensor
• Operating at a low supply voltage of 3 V
• Strong output sinking capacity, reaching up to 400 mA
• Versatile adjustment options for sensitivity and hysteresis
• Demonstrating dependability and durability

Uses of the Magnetic Polarity Detector Circuit

• Manufacturing: Ensures correct alignment of sensors in devices like speedometers and compasses.
• Magnetic Field Mapping: Useful in scientific and industrial fields for optimizing magnetic system performance.
• Quality Control: Verifies proper orientation of magnets in components such as speakers and motors.
• Orientation Detection: Used in robotics to determine magnetic object orientation for tasks like sorting.
• Security Systems: Integrated into door sensors and alarms for monitoring door/window openings.
• Navigation: Determines Earth's magnetic field orientation for precise direction in compasses and navigation systems.
• Industrial Automation: Detects component, tool, or object orientation for correct positioning in automation.
• Material Characterization: Analyzes and characterizes magnetic materials in material science and research.
• Vehicle Speed Sensors: Measures vehicle speed by detecting magnetic markers on roads in automotive applications.
• Magnetic Field Safety: Ensures proper alignment and security of magnetic objects in areas with strong magnetic fields like MRI rooms.

 Where and How Do You Order Such Boards?

Looking at the PCBWay website, I discovered three critical features while ordering your PCB for fabrication and assembly. Through PCBWay, you can request a turkey project where PCBWay supplies the parts, a kit where the customer provides all the details, or a combo where the customer gives some of the features while PCBWay does the rest. This service depends on the customer's preference, thus making PCBWay one of the most flexible fabrication houses I can always recommend to a friend.