The **KFS-1B-R** is a specific model of a **water flow sensor** (often categorized under flow switches). It is widely used in industrial equipment, water heaters, and laser cooling systems to monitor the movement of liquid through a pipe. --- ## 1. Technical Specifications The following table outlines the typical electrical and physical characteristics of the KFS-1B-R sensor: | Parameter | Specification | | :--- | :--- | | **Switch Type** | Reed Switch (Magnetic) | | **Contact Form** | Normally Open (NO) | | **Max Contact Rating** | 10W / 70W (Depending on version) | | **Max Switching Voltage** | 100V DC / 220V AC | | **Max Switching Current** | 0.5 A | | **Mounting Orientation** | Vertical or Horizontal | | **Material** | Plastic (usually high-grade ABS or PP) | | **Connection Thread** | G1/2" (Standard) | --- ## 2. Internal Components & Working Principle The KFS-1B-R operates on a relatively simple but reliable electromechanical principle. It does not require a constant power supply to "sense"; it acts as a passive switch. ### Key Electronic Parts: 1. **Magnetic Float (Piston):** Inside the plastic housing is a floating component containing a permanent magnet. As water flows, the pressure pushes this float upward or forward. 2. **Reed Switch:** This is the core electronic component. It consists of two ferrous metal reeds encased in a glass envelope. 3. **Housing/Body:** A non-magnetic chamber that allows the magnetic field to pass through to the switch without interference. ### How it Works: * **Idle State:** When there is no water flow, the magnetic float stays at the bottom due to gravity or a spring. The Reed Switch remains **Open** (no electrical continuity). * **Active State:** When water flows at a sufficient rate (the "start flow rate"), the float is lifted. The magnetic field from the float closes the contacts of the Reed Switch. * **Signal Output:** The closed circuit sends a signal to a PLC, microcontroller (like Arduino), or a relay to indicate that liquid is moving. --- ## 3. Wiring and Integration Since the KFS-1B-R is a **passive switch**, it should be treated like a button in a circuit. ```cpp // Example: Connecting KFS-1B-R to an Arduino int flowSensorPin = 2; // Connected to one wire of the KFS-1B-R void setup() { pinMode(flowSensorPin, INPUT_PULLUP); // Use internal pull-up resistor Serial.begin(9600); } void loop() { int status = digitalRead(flowSensorPin); if (status == LOW) { Serial.println("Flow Detected!"); } else { Serial.println("No Flow."); } } ``` --- ## 4. Important Usage Notes * **Current Limits:** Never connect a high-power pump directly to the KFS-1B-R. The internal reed switch is fragile and will weld shut if the current exceeds ~0.5A. Always use a **Relay** or **SSR** for high loads. * **Debris:** Because it uses a moving piston, it is sensitive to particles. It is highly recommended to install a filter upstream to prevent the magnet from getting stuck. * **Orientation:** Ensure the arrow on the body matches the direction of the water flow.