The **MF-RHS800** is a specific model within the **Polymer Positive Temperature Coefficient (PPTC)** resettable fuse family, manufactured by **Bourns**. These components are widely used for overcurrent protection in electronic circuits. --- ## 1. Technical Specifications The MF-RHS series is designed specifically for high-temperature environments (up to 125°C), making it suitable for automotive and industrial applications. | Parameter | Specification | | :--- | :--- | | **Model Number** | MF-RHS800 | | **Hold Current ($I_{hold}$)** | 8.0 Amperes | | **Trip Current ($I_{trip}$)** | 13.6 Amperes | | **Max Voltage ($V_{max}$)** | 16 Volts (DC) | | **Max Current ($I_{max}$)** | 100 Amperes | | **Operating Temperature** | -40°C to +125°C | | **Form Factor** | Radial Leaded (Through-hole) | --- ## 2. How It Works The MF-RHS800 acts as a "resettable fuse." Its operation is based on the physical properties of its conductive polymer: 1. **Normal State:** The device has a very low resistance, allowing current to flow to the load. 2. **Fault State (Overcurrent):** If the current exceeds the trip threshold ($I_{trip}$), the polymer heats up rapidly. This heat causes the polymer to expand, breaking the conductive chains and significantly increasing the resistance. 3. **Protection:** This high-resistance state limits the current to a safe leakage level, protecting downstream components. 4. **Reset:** Once the power is removed and the fault is cleared, the device cools down, the polymer contracts, and the conductive paths are restored. --- ## 3. Key Applications Because the "RHS" designation indicates **High-Temperature Radial Leaded** components, it is commonly found in: * **Automotive Electronics:** Protection for motors, actuators, and ECU power lines. * **Industrial Controls:** Sensors and actuators in high-heat environments. * **Power Supplies:** Secondary protection for DC/DC converters. --- ## 4. Part Marking Identification You can identify this part on a PCB by the following marking pattern typically found on the yellow or brown coating: ```text B (Bourns Logo) RHS800 Date Code (e.g., 2A) ```