The term **105C-R** typically refers to specifications found on **Electrolytic Capacitors**. This marking is a shorthand used by manufacturers to denote the component's thermal endurance and specific series characteristics. --- ### Breakdown of the Marking | Component Part | Meaning | Description | | :--- | :--- | :--- | | **105°C** | **Temperature Rating** | This is the maximum ambient operating temperature the capacitor can withstand while maintaining its functional life. | | **-R** | **RoHS Compliant** | Often indicates the part is "Restricted Hazardous Substances" compliant (Lead-free). | | **R (Series)** | **Low ESR / High Reliability** | In many manufacturer catalogs (like CapXon or Lelon), 'R' denotes a specific series optimized for low impedance or high ripple current. | --- ### Technical Significance of the 105°C Rating Standard electrolytic capacitors are often rated at **85°C**. Upgrading to a **105°C** part provides several advantages: 1. **Extended Lifespan:** According to *Arrhenius' Law*, for every 10°C decrease in operating temperature below the rated limit, the life of an electrolytic capacitor approximately doubles. A 105°C unit will last significantly longer than an 85°C unit when used in the same environment. 2. **Heat Dissipation:** These parts are better suited for power supplies (SMPS), LED drivers, and motherboards where internal heat buildup is common. 3. **Reliability:** They use higher-quality electrolytes that are less prone to "drying out" or leaking under thermal stress. --- ### Common Applications Components marked with **105C-R** are standard in the following devices: * **AC/DC Adapters:** Where components are packed tightly and heat cannot escape easily. * **Motherboards:** Specifically near the CPU VRM (Voltage Regulator Modules). * **LCD/LED Monitors:** Used in the internal power board to handle high-frequency switching. * **Industrial Equipment:** Where 24/7 operation requires high-durability components. --- ### Identification Example If you see a capacitor marked: `470uF 25V 105°C-R` * **470uF:** Capacitance (Storage capacity). * **25V:** Maximum working voltage. * **105°C:** Maximum heat tolerance. * **-R:** RoHS compliant / Low ESR series.