The **GLP2-125-R-54** is a high-precision linear potentiometer (often referred to as a "pencil-type" displacement sensor) manufactured by **Gefran**. It is designed to measure absolute linear displacement by converting mechanical movement into a proportional electrical signal. --- ### 1. Core Technical Specifications The electronic performance of this part is characterized by its high linearity and resistive track technology. | Feature | Specification | | :--- | :--- | | **Model Series** | GLP (Pencil type) | | **Nominal Stroke** | 125 mm | | **Resistance (Rt)** | 5 kΩ (standard for this length) | | **Linearity Tolerance** | ± 0.05% | | **Resistance Tolerance** | ± 20% | | **Repeatability** | < 0.01 mm | | **Max Supply Voltage** | 60 V | | **Output Type** | Analog (Potentiometric) | | **Protection Class** | IP54 (Dust and splash proof) | --- ### 2. Key Electronic Components & Design #### A. Conductive Plastic Track The "heart" of the GLP2-125 is a **conductive plastic resistive element**. Unlike wire-wound potentiometers, conductive plastic provides: * **Infinite Resolution:** Because the surface is smooth, the electrical change is continuous rather than stepped. * **Long Life:** It typically lasts for >100 million cycles because the friction is minimal. #### B. Multi-finger Wiper To ensure a stable electrical output even under vibration, the internal "wiper" (the part that moves along the resistance track) uses a multi-finger contact system. This reduces electrical noise (contact resistance variation) and ensures signal integrity. #### C. Electrical Connections The sensor operates as a **voltage divider**. * **Terminal 1 & 3:** Connected to the ends of the resistive track (Excitation voltage). * **Terminal 2:** The wiper output (Signal). * **Recommended Current:** The wiper current should be kept as low as possible (typically < 0.1 µA) to prevent thermal damage to the plastic track. --- ### 3. Protection and Build (IP54) The **"54"** in the part number refers to the **IP Rating**: * **5:** Protected against limited dust ingress. * **4:** Protected against water splashes from any direction. * The electronic internals are housed in an anodized aluminum case to provide electromagnetic shielding and physical protection. --- ### 4. Typical Application Circuit The sensor is generally used in a ratiometric configuration: ```text V_in (+) ----[ Terminal 1 ] | |----[ Terminal 2 (Output Signal) ] | V_in (-) ----[ Terminal 3 ] ``` *Note: The output voltage is directly proportional to the position of the rod.*