Based on the part number provided, this component belongs to the **CGH Series** manufactured by **TT Electronics (IRC)**. This specific series consists of high-voltage, glass-glaze metal film resistors designed for precision and reliability in harsh environments. --- ## 1. Part Number Breakdown: CGH-1/4-50-2205-D-LF The alphanumeric code provides specific technical details about the resistor's construction and performance: | Segment | Meaning | Specification | | :--- | :--- | :--- | | **CGH** | Series | Metal Glaze, High Voltage Resistor | | **1/4** | Power Rating | 0.25 Watts (1/4 Watt) at 70°C | | **50** | Temp. Coefficient | 50 ppm/°C (Stability over temperature) | | **2205** | Resistance Value | 22 Megohms (220 + 5 zeros) | | **D** | Tolerance | ±0.5% (High precision) | | **LF** | Lead Finish | Lead-Free / RoHS Compliant | --- ## 2. Technical Specifications These resistors are engineered for high-stress applications where standard film resistors would fail due to voltage arcing or thermal drift. * **Resistance Range:** 22 MΩ (Megohms). * **Voltage Rating:** Typically rated for 750V to 1,000V (depending on specific mounting). * **Operating Temperature:** -55°C to +150°C. * **Construction:** Thick film "Metal Glaze" fired onto a high-grade ceramic core, then protected by a rugged blue epoxy coating. --- ## 3. Key Applications Because of the high resistance (22M) and tight tolerance (0.5%), this part is typically found in: 1. **High Voltage Power Supplies:** Used as voltage dividers or bleeder resistors. 2. **Medical Equipment:** High-impedance circuits in imaging or diagnostic tools. 3. **Measurement Instrumentation:** Precision sensing in multimeters or oscilloscopes. 4. **Aerospace & Defense:** Where long-term stability under thermal cycling is required. --- ## 4. Equivalent Series Comparison | Feature | CGH Series (Metal Glaze) | Standard Carbon Film | | :--- | :--- | :--- | | **Voltage Handling** | Superior (High Surge) | Poor | | **Precision** | High (Up to 0.5%) | Low (5% - 10%) | | **Stability** | Excellent over time | Drifts with age |