The **3P31-R** refers to a specific series of miniature, high-reliability rotary switches often manufactured by brands like **Grayhill** (specifically the Series 71 or similar miniature lines) or specialized industrial component suppliers. These are designed for precision switching in tight spaces. --- ### 1. Key Technical Specifications The "3P" typically denotes a **3-Pole** configuration, and the "31" often relates to the angle of throw or a specific model number within a manufacturer's catalog. | Feature | Description | | :--- | :--- | | **Number of Poles** | 3 Poles (Simultaneous switching of 3 independent circuits) | | **Indexing/Throw** | Usually 30° or 36° (depending on the sub-series) | | **Current Rating** | Typically 250mA at 115 VAC or 30 VDC | | **Contact Material** | Often Silver alloy or Gold-plated Brass | | **Mounting Type** | Through-hole (PCB) or Panel Mount | ### 2. Physical Construction The device is composed of several critical layers: 1. **The Bushing:** The threaded part that mounts to a panel. 2. **The Shaft:** The rotating element used by the operator to change positions. 3. **The Wafer/Deck:** The insulating disk where the contacts are located. 4. **Terminals:** Solder lugs or PC pins that exit the rear or sides for electrical connection. ### 3. Circuit Configuration (3P) As a **3-Pole** switch, this part acts like three separate switches controlled by a single knob. * **Pole A:** Contacts 1 through N * **Pole B:** Contacts 1 through N * **Pole C:** Contacts 1 through N * *Application:* This is ideal for switching 3-phase signals or simultaneously switching ground, power, and signal lines. ### 4. Common Applications * **Test & Measurement:** Selecting different input ranges or sensors. * **Audio Equipment:** Switching between different stereo channels plus a control line. * **Avionics:** Used in cockpits due to their high vibration resistance and small footprint. * **Industrial Controls:** Setting modes of operation for complex machinery. ### 5. Part Number Breakdown (General Grayhill/Industry Standard) | Segment | Meaning | | :--- | :--- | | **3P** | **3 Poles:** The number of separate common terminals. | | **31** | **Angle/Positions:** Often indicates a 30-degree indexing (12 positions max). | | **-R** | **RoHS Compliant:** Indicates the part meets environmental standards (Lead-free). | ---