H21A1 Slotted Optical Switch Sensor DIP (H21A1 Opto Interrupter / IR Slot Sensor)

The H21A1 Slotted Optical Switch Sensor is a transmissive infrared optical sensor designed for non contact object detection, position sensing, speed measurement, and motion detection. It consists of a gallium arsenide infrared emitting diode and an NPN silicon phototransistor positioned opposite each other inside a slotted housing.

When an object passes through the slot and interrupts the infrared beam, the phototransistor output changes state. This beam interruption principle provides reliable and repeatable detection for encoder systems, printers, counters, motion sensing, and industrial automation.

Key Features -

• H21A1 slotted optical switch

• Through beam infrared detection

• Integrated IR LED and NPN phototransistor

• Approximately 3mm slot width

• Non contact object detection

• Fast response

• High sensitivity

• Ambient light rejection

• Compact slotted DIP package

• Suitable for through hole PCB mounting

Specifications -

• Product Type = Slotted Optical Switch

• Model = H21A1

• Sensor Type = Slotted Opto Interrupter

• Sensing Method = Through Beam Detection

• Slot Width = Approximately 3mm

• Output Type = Phototransistor Output

• Forward Current = Up to 50mA

• Collector Current = Up to 20mA

• Collector Emitter Voltage = Up to 30V

• Response Time = Approximately 8µs to 50µs

• Operating Temperature = -25°C to +85°C

• Mounting Type = Through Hole

• Package Type = Slotted DIP with PC Pins

• Application = Optical Object and Motion Detection

Applications -

• Encoder systems

• Speed sensing

• Position detection

• Motion detection

• Object counting

• Printer mechanisms

• Rotation sensing

• Industrial automation

• Embedded systems

• Optical switching