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Small black plastic sensor with IR LED phototransistor and two resistors

Adafruit

Adafruit Reflective IR Sensor 470 10K Resistors Engineering Development Tool

SKU CH-81Z5-8TN6J

Detects light-coloured objects up to 5mm away using an IR LED and phototransistor, and includes 470 ohm and 10K resistors for circuit integration

  • Product typePrototyping Products
  • Detects light-coloured objects at ~5 mm range
  • Dark surfaces absorb IR and remain invisible
  • Includes 470 ohm LED bias and 10K pull-up resistors
  • Simple plastic housing with IR LED and phototransistor
  • Ideal for object-passage detection or basic rotary encoding

Reflective IR Sensor for Prototyping

This sensor pairs an IR LED with a phototransistor in a simple plastic casing. It detects light-colored objects at roughly 5 mm distance. Dark or black surfaces absorb the IR light and remain undetected. The module includes a 470 ohm resistor for the LED and a 10K resistor for the phototransistor pull-up.

Detecting Object Passage and Encoder Tasks

The sensor suits projects that need to know when an item passes a fixed point. It can also read striped encoder wheels to measure rotational speed. Builders who need reliable detection of dark surfaces or longer sensing ranges should choose a different technology.

Close-Range Reflectivity Sensing

White and light materials reflect enough IR to trigger the phototransistor reliably at the specified gap. Performance drops quickly beyond that distance or with low-reflectivity targets. The included resistors simplify breadboard wiring for immediate testing.

How it compares

Measured against everything we stock in Engineering Workstations & Dev Kits, at today’s prices. Recalculated every night.

Price $5.99
Cheaper than about 90% of the 170 comparable items (median $11.49).

Specifications

Product
Product typePrototyping Products

Questions about this item

What mounting options does the simple plastic casing of this reflective IR sensor provide?

The sensor has a simple plastic casing with no integrated mounting holes or brackets; it is designed for breadboard or custom fixture use.

How do I wire the included 470 ohm and 10K resistors when installing this sensor on a breadboard?

Use the 470 ohm resistor to bias the IR LED anode, and the 10K resistor as a pull-up on the phototransistor collector to the supply rail.

Will the IR LED or phototransistor in this sensor require periodic replacement under normal use?

The IR LED and phototransistor are solid-state components with no moving parts and do not require scheduled replacement.

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