Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Model Number | KY-003 |
| Sensor Type | Unipolar Hall Effect Switch |
| IC Chip | A3144E |
| Operating Voltage | 4.5V to 24V DC |
| Output Type | Digital Open Collector |
| Operating Current | Typically 10mA |
| Pin Configuration | 3-Pin (VCC, GND, OUT) |
| PCB Dimensions | 15mm x 10mm |
| Mounting Hole | 3mm Diameter |
| Application | Speed Detection, Position Sensing, Arduino Projects |
Anonymous
Mar 21, 2026
Rating: 4/5
Good value, clear instructions needed
The sensor itself is high quality and detects magnets instantly. I deducted one star because there were no printed instructions included, but finding the pinout online was easy enough.
Anonymous
Mar 10, 2026
Rating: 5/5
Great for beginners
As someone new to electronics, this was very easy to wire up. Just three pins and it worked immediately. I'm using it to detect when a door closes in my smart home project.
Anonymous
Mar 10, 2026
Rating: 5/5
Reliable magnetic switch
I needed a lightweight solution for RPM monitoring on a drone propeller guard test rig. This little board is light, sturdy, and hasn't failed once after hundreds of cycles.
Anonymous
Mar 06, 2026
Rating: 5/5
Bulk buy success
Bought ten of these for our classroom kits. Every single one functioned perfectly out of the box. Students love seeing the LED light up when they bring a magnet close.
Anonymous
Mar 04, 2026
Rating: 4/5
Solid performance
Works exactly as described for a unipolar switch. It only triggers on one pole of the magnet, which is important to remember during installation. Good build quality for the price.
Anonymous
Mar 03, 2026
Rating: 5/5
Perfect for Arduino speed counters
This module works flawlessly with my Arduino Uno. I used it to build a tachometer for a small DC motor, and the response time is incredibly fast. The onboard LED indicator is a nice touch for debugging.
Q: Can I use this directly to drive a relay?
A: No, the output current of this module is too low to drive a relay directly. You should use the output signal to trigger a transistor or a dedicated driver circuit that can handle the relay's current requirements.
Q: Does this module work with 3.3V logic levels like ESP32?
A: Yes, the A3144E operates down to 4.5V for power, but the output is open-collector. You can use it with 3.3V systems by powering the VCC at 5V and using a pull-up resistor to 3.3V on the output pin, or simply rely on the internal pull-up of your microcontroller if compatible.
Q: What is the maximum distance for magnet detection?
A: Detection distance depends heavily on the strength of the magnet used. With a standard neodymium magnet, it typically detects within 5mm to 10mm. Stronger magnets will increase this range slightly.
Q: Is this sensor bipolar or unipolar?
A: This is a unipolar Hall effect switch (A3144E). It activates only when a specific magnetic pole (usually South) approaches and remains on until the magnetic field drops below the release point.
Q: Does the package include magnets?
A: No, this package includes only the Hall Sensor Module board. Magnets are not included and must be sourced separately based on your specific project needs.
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