H21A1 Slotted Optical Switch Sensor DIP (H21A1 Opto Interrupter)
The H21A1 Slotted Optical Switch is a transmissive optical sensor designed for non contact object detection and position sensing. It consists of a gallium arsenide infrared emitting diode and an NPN silicon phototransistor mounted opposite each other inside a slotted housing. When an object passes through the slot and interrupts the IR beam, the output of the phototransistor switches state, enabling precise detection.
The sensor operates on the principle of light beam interruption, where an opaque object blocks the IR path between emitter and detector. This makes it highly reliable for encoder and motion sensing applications.
The H21A1 is widely used in India for embedded systems, industrial electronics, and automation systems. It is valued for its robustness, fast response, and consistent performance in applications such as speed sensing, position detection, and object counting.
Key Features
- Slotted Optical Switch: Through beam IR detection
- 3mm Slot Width: Standard gap for encoder and detection systems
- Integrated IR LED and Phototransistor: Complete sensing solution
- Fast Response Time: Suitable for high speed switching
- High Sensitivity: Reliable object interruption detection
- Ambient Light Rejection: Stable operation in varying conditions
Specifications
- Sensor Type: Slotted opto interrupter
- Sensing Method: Through beam detection
- Slot Width: Approx 3mm
- Output Type: Phototransistor output
- Forward Current: Up to 50mA
- Collector Current: Up to 20mA
- Collector Emitter Voltage: Up to 30V
- Response Time: Approx 8µs to 50µs
- Operating Temperature: -25°C to +85°C
- Mounting Type: Through hole
- Package Type: Slotted DIP with PC pins
- Applications: Encoder systems speed sensing position detection printers industrial electronics embedded systems
Pinout Configuration DIP4 Layout
- Anode pin of IR emitter
- Cathode pin of IR emitter
- Collector pin of phototransistor
- Emitter pin of phototransistor
