The part number **47LR-140G-R** generally refers to a specific type of **Gas Discharge Tube (GDT)**, which is a surge arrestor component used to protect sensitive electronic equipment from overvoltage transients (like lightning strikes or power surges). ### 1. Component Identification This component is designed to act as a high-impedance "open circuit" during normal operation and a low-impedance "short circuit" when a voltage spike occurs, diverting excess energy to the ground. | Feature | Specification Details | | :--- | :--- | | **Component Type** | Gas Discharge Tube (GDT) / Surge Arrestor | | **Series** | 47LR Series | | **Configuration** | 2-Electrode Axial Lead | | **DC Spark-over Voltage** | 140V (Typical for the "140" designation) | | **Tolerance** | ±20% (Standard G-grade tolerance) | | **RoHS Status** | Compliant (Indicated by the "-R" suffix) | --- ### 2. Key Technical Characteristics #### A. Electrical Performance * **DC Spark-over Voltage:** The voltage at which the gas inside the tube ionizes and becomes conductive. For this model, it is approximately **140V**. * **Insulation Resistance:** Usually very high (>1 GΩ), ensuring minimal leakage current during normal circuit operation. * **Capacitance:** Extremely low (typically <1.5 pF), making it ideal for high-speed data line protection as it does not distort signals. #### B. Physical Design * **Form Factor:** Axial-leaded ceramic body. This allows for "through-hole" mounting on Printed Circuit Boards (PCBs). * **Construction:** Consists of two electrodes sealed in a ceramic envelope filled with a specific noble gas mixture. --- ### 3. Applications and Use Cases Because of its low capacitance and high current handling capability, the 47LR-140G-R is commonly used in: 1. **Telecommunications:** Protecting phone lines, modems, and fax machines. 2. **Industrial Controls:** Safeguarding signal lines in harsh electrical environments. 3. **Power Supplies:** Providing secondary protection against line surges. 4. **Data Networks:** Protecting Ethernet or CATV lines from transient spikes. --- ### 4. Circuit Implementation Example In a typical protection circuit, the GDT is placed in parallel with the load. ```mermaid graph LR Input[Line In] --- GDT((47LR-140G-R)) GDT --- Ground Input --- Load[Sensitive Electronics] ``` ---