QTR-8RC Line Following Reflectance IR Sensor Array

Description

QTR-8RC is a reflectance sensor array but intended as a line sensor. It can be used as a general-purpose proximity IR or reflectance sensor. The device has 8 pairs of IR LEDs and phototransistors mounted on a 9.525 mm pitch.

Each phototransistor in the module is followed by a pull-up resistor that forms a voltage divider and produces an analog voltage output between 0 to 5V as the function of the reflectance sensor. All the outputs are independent but LEDs are paired to halve the current consumption. The LEDs are controlled by MOSFET with a gate normally pulled high that allows LEDs to turn off by setting the MOSFET gate at low voltage.