The **201UR503C** is a specific model of a **trimmer potentiometer** (variable resistor) commonly used for fine-tuning circuit parameters on a printed circuit board (PCB). It is part of the "201" series, typically manufactured by companies like **CTS** or compatible brands. --- ### 1. Technical Specifications The part number can be decoded to understand its electrical and physical properties: | Feature | Specification | Description | | :--- | :--- | :--- | | **Part Series** | 201 | 3/4" (19mm) Rectangular Trimmer | | **Resistance Value** | 50k $\Omega$ | "503" = 50 + 000 (3 zeros) | | **Tolerance** | ±10% or ±20% | Standard deviation from nominal value | | **Power Rating** | 0.5 Watts | Maximum power at 70°C | | **Mounting Type** | Through-hole | Pin style "C" (Vertical mount) | | **Adjustment Type** | Multi-turn | Allows for high precision tuning | --- ### 2. Component Composition The 201UR503C is composed of three primary internal elements: * **Resistive Element:** Usually made of **Cermet** (Ceramic-Metal composite), which provides excellent stability and low temperature coefficient. * **Wiper:** A metal contact that slides across the resistive element when the screw is turned. * **Lead Screw:** A fine-threaded screw that allows the wiper to move incrementally, typically requiring 20 to 25 full turns to move from 0 to 50k $\Omega$. --- ### 3. Pin Configuration and Circuit Symbol Most 201 series trimmers use a standard 3-pin layout: 1. **Pin 1:** Terminal (Start of element) 2. **Pin 2:** Wiper (Connected to the adjustment screw) 3. **Pin 3:** Terminal (End of element) ```mermaid graph LR A[Pin 1] --- R[Resistor] R --- B[Pin 3] W[Pin 2 - Wiper] --> R ``` --- ### 4. Common Applications Due to its multi-turn precision, this component is used in environments where "set and forget" calibration is required: * **Voltage Regulators:** Setting the exact output voltage. * **Sensor Calibration:** Adjusting the threshold for light, temperature, or pressure sensors. * **Timing Circuits:** Fine-tuning the frequency of an oscillator or the delay of a timer. * **Audio Equipment:** Balancing gain levels between different stages. ---