The **A1JK-R** is a specific model within the **A1 series of photoelectric sensors**, typically manufactured by companies like **Azbil** (formerly Yamatake). This sensor is designed for industrial automation to detect the presence or absence of objects using light. Below is a breakdown of its electronic components, specifications, and functions. --- ### 1. Key Specifications The A1JK-R is a **Retro-reflective** type sensor, meaning it emits light that must bounce off a reflector and return to the sensor head to complete the circuit. | Feature | Specification | | :--- | :--- | | **Detection Method** | Retro-reflective | | **Sensing Distance** | Typically 0.1m to 4m (varies by reflector) | | **Power Supply** | 24 to 240V AC / 12 to 240V DC (Multi-voltage) | | **Output Type** | Relay Output (SPDT) | | **Current Consumption** | 2W or less | | **Response Time** | 20ms or less | | **Indicator** | Red LED (Operation indicator) | --- ### 2. Internal Electronic Parts & Components The internal architecture of the A1JK-R consists of four main functional blocks: #### A. The Emitter (Light Source) * **LED:** Usually a high-intensity Infrared or Visible Red LED. * **Oscillator Circuit:** Drives the LED at a specific frequency to ensure the receiver can distinguish the sensor's light from ambient factory lighting. #### B. The Receiver (Sensor) * **Photodiode/Phototransistor:** Converts the incoming light energy into an electrical signal. * **Preamplifier:** Boosts the weak signal from the photodiode. * **Band-pass Filter:** Only allows signals at the specific frequency of the emitter to pass, preventing false triggers from sunlight or flashlights. #### C. Control Logic & Switching * **Schmitt Trigger:** Converts the analog signal into a clean digital "On/Off" signal. * **Relay (The "R" in A1JK-R):** Unlike NPN/PNP transistors, this model uses a mechanical relay. This allows it to switch higher currents and different voltages than the supply voltage. * **Sensitivity Potentiometer:** A small screw on the housing that allows the user to adjust the detection threshold. #### D. Power Supply Unit * **Bridge Rectifier:** Allows the sensor to operate on both AC and DC power. * **Regulator:** Stabilizes the input voltage to protect the internal sensitive electronics. --- ### 3. Wiring Configuration Because it uses a relay output, the wiring typically involves five wires: 1. **Power (2 wires):** Connects to the AC or DC power source. 2. **Common (COM):** The shared terminal for the relay. 3. **Normally Open (NO):** Closes when an object is detected (or not, depending on Light-ON/Dark-ON settings). 4. **Normally Closed (NC):** Opens when the relay is energized. --- ### 4. Application Advantages * **Universal Voltage:** Can be integrated into almost any power environment (110V AC, 220V AC, or 24V DC). * **Long Range:** Retro-reflective sensors cover more distance than diffuse types. * **Simplified Wiring:** Only one side (the sensor) needs wiring; the other side is just a plastic reflector.