The **KAS-AC-R** refers to a high-precision, industrial-grade capacitive proximity sensor (often associated with manufacturers like Rechner Sensors). These devices are designed to detect both metallic and non-metallic objects (liquids, powders, solids) through non-conductive walls. ### 1. Key Electronic Specifications The "AC" in the model name typically signifies that the device operates on Alternating Current, while the "R" often denotes a Relay output or specific Housing/Range characteristics. | Feature | Typical Specification | | :--- | :--- | | **Operating Voltage** | 20...250 V AC / DC (Universal) | | **Output Type** | Relay (Changeover/SPDT) | | **Switching Distance** | Adjustable (e.g., 2mm to 20mm) | | **Circuit Protection** | Overvoltage and polarity protection | | **Frequency** | 5 Hz (Relay limited) | --- ### 2. Internal Electronic Components The functionality of the KAS-AC-R is driven by several core electronic stages: 1. **Oscillator Circuit:** The heart of the sensor. It creates an electrostatic field at the active face. When a material enters this field, the capacitance changes, affecting the oscillator's amplitude. 2. **Trigger Stage:** This circuit monitors the oscillator. Once the change in capacitance reaches a predefined threshold (the switching point), it sends a signal to the output stage. 3. **Potentiometer:** An internal variable resistor used to calibrate sensitivity. This allows the sensor to "tuned out" a plastic container wall and only detect the liquid inside. 4. **Relay Output:** Unlike NPN/PNP transistors, the "R" model uses a mechanical or solid-state relay. This provides potential-free switching, allowing it to control heavy loads directly. --- ### 3. Wiring Configuration The device usually features a multi-wire setup to handle both power and the dry contact relay switching. ```yaml Terminal/Wire Color | Function -------------------|----------------------- Brown | L1 (Line Voltage) Blue | N (Neutral) White | Relay Common (COM) Black | Relay Normally Open (NO) Grey | Relay Normally Closed (NC) ``` --- ### 4. Application Context * **Level Control:** Detecting the fill level of grain, plastic pellets, or liquids in a silo. * **Leak Detection:** Placed in drip trays to trigger an alarm if moisture is detected. * **Object Counting:** Detecting boxes or parts on a high-voltage AC conveyor system without needing a separate DC power supply.