The **PM-K24-R** is a subminiature, K-type u-shaped photoelectric sensor manufactured by Panasonic (formerly Sunx). It is widely used in industrial automation for sensing the presence or position of objects through a small slot. --- ### 1. Key Technical Specifications The following table outlines the core electronic and physical characteristics of the PM-K24-R: | Feature | Specification | | :--- | :--- | | **Sensing Range** | 5 mm (Fixed) | | **Minimum Sensing Object** | 0.8 x 1.8 mm (Opaque) | | **Supply Voltage** | 5 to 24 V DC ±10% | | **Current Consumption** | 15 mA or less | | **Output Type** | NPN Open-collector transistor | | **Output Operation** | Dual Output (Light-ON / Dark-ON) | | **Response Time** | 20 µs or less under light received | | **Cable Type** | Flexible R-type (Robot cable) | --- ### 2. Internal Electronic Components The PM-K24-R operates as a **Transmissive (Through-beam)** sensor. Its internal circuitry consists of two primary sides: #### A. Emitter Side (Infrared LED) * **Light Source:** It utilizes an Infrared LED (peak emission wavelength: 855 nm). * **Function:** Continuously emits a beam of infrared light across the 5mm gap toward the receiver. #### B. Receiver Side (Phototransistor) * **Sensor:** A high-speed phototransistor detects the presence of the IR beam. * **Signal Processing:** Internal circuitry converts the light levels into a digital signal. * **Output Transistor:** An NPN transistor acts as a switch. When triggered, it pulls the output signal to the negative (0V) rail. --- ### 3. Wiring Configuration The "R" in the model name indicates a **Flexible Robot Cable**, designed to withstand repeated bending in moving parts. The sensor typically uses a 4-wire system: | Wire Color | Connection | Description | | :--- | :--- | :--- | | **Brown** | +V | Positive Power Supply (5-24V DC) | | **Blue** | 0V | Ground / Negative | | **Black** | Output 1 | Light-ON (Conducts when beam is NOT broken) | | **White** | Output 2 | Dark-ON (Conducts when beam IS broken) | --- ### 4. Distinctive Features * **Compact Size:** The "K" shape allows the sensor to be mounted in tight spaces, often used for limit detection in linear actuators. * **High Speed:** With a response time of 20 microseconds, it can detect objects moving at high frequencies or fast-rotating discs with slits. * **Reverse Polarity Protection:** The internal electronics are protected against accidental reverse wiring of the power supply.