Functional description
The Pololu QTR-L-1A reflection sensor carries a rectangular infrared LED and a rectangular phototransistor, both pointing to the front edge of the board. The phototransistor is connected to a pull-up resistor to form a voltage divider that produces an analog voltage output between 0 V and VIN (typically 5 V) depending on the reflected IR. A lower output voltage is an indication of a higher reflection.
The LED current limiting resistor is set to deliver approximately 17 mA to the LED at a VIN of 5 V. The LED current limiting resistor is set to a value of 5 V, and the LED current limiting resistor is set to a value of 17 mA. The current requirement can be met by some microcontroller I/O lines so that the sensor can be switched up and down via an I/O line to save energy.
>This sensor is designed for use with the board perpendicular to the surface to be scanned, and narrow beam lenses integrated into the infrared LED and phototransistor housings provide an effective range of approximately 1″ (25 mm). Due to its small size, several units can easily be arranged to suit various applications such as line scanning and neckline and edge detection. The QTR-L-1A is sold in packs of two units.
Specifications
- Dimensions: 0.3″ × 0.35″ × 0.12″ (without installed optional pinheaders)
- Operating voltage: 5.0 V
- Supply current: 17 mA
- Output format: analog voltage
- Output voltage range: 0 to supply voltage (depending on operating environment)
- Optimum switching distance: 0.125″ to 0.25″ (3 mm to 6 mm)
- Maximum recommended switching distance: 1″ (25 mm)
- Weight without head pins: 0.006 oz (0.2 g)
| Shipping weight: | 0,01 Kg |
