The **81ES2AB** is a specific part number typically associated with high-precision **Potentiometers** (variable resistors) manufactured by **Bourns**. These components are widely used in industrial controls, medical equipment, and professional audio gear due to their long life and high reliability. --- ### 1. Component Specification Table The part number follows a specific nomenclature. Here is the breakdown of the technical specifications for the 81ES2AB series: | Feature | Specification | | :--- | :--- | | **Component Type** | Single-Turn Potentiometer | | **Element Type** | Cermet (Ceramic/Metal composite) | | **Standard Resistance** | Often 1K, 5K, or 10K Ohms (depending on full code) | | **Tolerance** | ±5% or ±10% | | **Power Rating** | 2.0 Watts at 70°C | | **Operating Temp** | -40°C to +125°C | | **Rotational Life** | Up to 100,000 cycles | --- ### 2. Physical Design and Construction The "81" series is characterized by its **Model 81/82** industrial design. Key physical attributes include: * **Housing:** 5/8" (16mm) square plastic or metal body. * **Terminals:** PC pins (for circuit board mounting) or solder lugs. * **Bushing/Shaft:** Usually features a metal bushing and a metal shaft for durability in heavy-duty applications. * **Sealing:** These units are often "sealed" to withstand board washing and harsh environmental dust/moisture. --- ### 3. Key Electronic Characteristics The "ES" in the part number often refers to specific mechanical or electrical configurations: 1. **Cermet Element:** Unlike carbon potentiometers, Cermet provides a very low Temperature Coefficient (TC), meaning the resistance remains stable even as the part heats up. 2. **Linear Taper:** The "A" in the suffix usually denotes a linear output, where the change in resistance is proportional to the degree of rotation. 3. **Low Noise:** Designed to minimize "crackle" or electrical noise during adjustment, making it suitable for precision instrumentation. --- ### 4. Common Applications Due to its rugged construction and precision, the 81ES2AB is found in: * **Industrial Process Controls:** Setting speed or temperature limits. * **Medical Equipment:** Calibrating diagnostic sensors. * **Test & Measurement:** Used in oscilloscopes or signal generators as fine-tuning knobs. ---