The **ST-10-R-B90** is a specific model within the **ST-10 series** of high-precision, sub-miniature rotary DIP switches, typically manufactured by companies like **Nidec Components (formerly Copal Electronics)**. Below is a detailed breakdown of its electronic and physical specifications. --- ## 1. Component Overview The ST-10-R-B90 is a **rotary code switch** designed for PCB mounting. It allows users to set binary-coded decimal (BCD) values manually, which are then read by a microcontroller or logic circuit. ### Key Specifications | Feature | Specification | | :--- | :--- | | **Code Type** | Real Code (Binary Coded Decimal - BCD) | | **Number of Positions** | 10 Positions (0-9) | | **Terminal Style** | Gull-wing (Surface Mount - SMT) | | **Actuator Style** | Recessed (Requires a screwdriver) | | **Orientation** | Side Actuation (Right Angle) | | **Contact Rating** | 100mA @ 5V DC (Switching), 100mA @ 50V DC (Non-switching) | --- ## 2. Technical Features ### Electrical Characteristics * **Contact Resistance:** Maximum $100m\Omega$. * **Insulation Resistance:** Minimum $1000M\Omega$ at 100V DC. * **Dielectric Strength:** 250V AC for 1 minute. * **Logic:** As the dial turns, specific pins are shorted to the "Common" pin to represent a 4-bit binary value (1, 2, 4, 8). ### Mechanical & Environmental * **Operating Torque:** 2 to 15 mN·m. * **Rotational Life:** 10,000 steps. * **Operating Temperature:** -40°C to +85°C. * **Sealing:** Washable (usually O-ring sealed) to withstand soldering flux and cleaning processes. --- ## 3. Truth Table (BCD Real Code) This table shows which pins are connected to the Common (C) terminal based on the dial position: | Position | 1 (2⁰) | 2 (2¹) | 4 (2²) | 8 (2³) | | :---: | :---: | :---: | :---: | :---: | | **0** | | | | | | **1** | ● | | | | | **2** | | ● | | | | **3** | ● | ● | | | | **4** | | | ● | | | **5** | ● | | ● | | | **6** | | ● | ● | | | **7** | ● | ● | ● | | | **8** | | | | ● | | **9** | ● | | | ● | --- ## 4. Typical Applications * **Address Setting:** Used in industrial automation (RS-485/CAN nodes) to set a device ID. * **Configuration:** Selecting modes on a PCB without needing a digital interface. * **Security/Access:** Setting a physical hardware pin code. ---