Based on technical specifications for marine and industrial instrumentation, the **KUS-C4-R** typically refers to a high-precision liquid level sensor (often a capacitive or reed-switch type) or a specific gauge variant produced by KUS (formerly Wema). Below is a breakdown of the electronic components and technical characteristics of this device. --- ## 1. Core Technical Specifications The electronics are designed to operate in harsh environments (marine, automotive, or industrial). | Feature | Specification | | :--- | :--- | | **Input Voltage** | 12V / 24V DC (Multi-voltage support) | | **Output Signal** | Resistive (0-190$\Omega$ or 240-33$\Omega$) or Voltage (0.5-4.5V) | | **Operating Current** | < 100mA | | **Resolution Range** | 10mm to 40mm (depending on length) | | **Protection Rating** | IP67 (Waterproof/Dustproof) | --- ## 2. Key Electronic Components ### A. The Sensing Element (Reed Switch Array) Inside the stainless steel tube, there is a printed circuit board (PCB) populated with a series of **magnetic reed switches** and precision **resistors**. * **Function:** As the float (containing a magnet) moves up and down the shaft, it triggers specific reed switches. * **Result:** This changes the total resistance of the circuit, which the gauge interprets as a fluid level. ### B. Signal Conditioning Circuitry The C4-R series includes an internal circuit to stabilize the output signal, preventing "needle bounce" caused by fuel sloshing in a moving tank. * **Integrated Resistors:** High-tolerance surface-mount resistors (SMD) ensure the output signal matches the standard calibration (e.g., European or American standards). * **Voltage Regulation:** Internal components protect the sensor from voltage spikes common in alternator-driven systems. ### C. Connection Interface The unit typically uses a standard wiring harness: 1. **Red Wire:** Power Input (+) 2. **Blue/Black Wire:** Ground (-) 3. **Signal Wire:** Connection to the gauge or NMEA2000 gateway. --- ## 3. Wiring Diagram (Electronic Logic) ```mermaid graph LR A[Power Source 12/24V] --> B[KUS-C4-R Sensor] B --> C{Internal Reed Matrix} C -->|Variable Resistance| D[Display Gauge / ECU] D --> E[Ground/Negative] ``` --- ## 4. Operational Advantages * **Non-Contact Sensing:** Because the magnet triggers the switches through the stainless steel wall, there is no mechanical wear on the electronic parts. * **Corrosion Resistance:** The PCB is typically encapsulated in epoxy or a sealed chamber to prevent oxidation.