User Manual

3
Product overview
The Whadda Inductive proximity sensor detection switch accurately detects metal objects that are
within 4 mm of the sensor head. When a metal object is detected, the built-in red LED lights up and the
black signal wire is internally shorted to ground through an NPN transistor. When no object is detected,
the signal is floating/high impedance.
Note: It is recommended to supply the sensor with no more than 6 V, and to put a series protection
resistor between the signal output of the sensor and digital input of your board when connected to 5 V
logic, such as Arduino® compatible boards.
Specifications
Supply voltage: 6 – 36 V DC
Sensor model: LJ12A3-4-Z / BX
Detection distance: 4 mm
Output signal: NPN (high impedance when no object is present, or ground when object is detected)
Cable length: ± 110 cm
Weight: 44 g
Wiring description
Pin
Name
Arduino® connection
BN (Brown wire)
Supply voltage (6 - 36 V DC)
-
BK (Black wire)
Signal output
Digital Pin
BU (Blue wire)
Ground
GND