## Overview of the VS-ST1280C..K Series The **VS-ST1280C..K** series consists of Phase Control Thyristors (SCRs) in a "Hockey Puk" (press-pack) configuration. These are high-power semiconductors designed for industrial applications requiring high current and high voltage regulation. --- ### 1. Key Technical Specifications Below are the primary electrical characteristics for this series: | Parameter | Symbol | Value (Typical) | | :--- | :---: | :--- | | **Average On-State Current** | $I_{T(AV)}$ | 1280 A | | **RMS On-State Current** | $I_{T(RMS)}$ | 2510 A | | **Repetitive Peak Reverse Voltage** | $V_{RRM}$ | 400 V to 600 V | | **Max. Peak One Cycle Surge** | $I_{TSM}$ | 23.5 kA (@ 50Hz) | | **Gate Trigger Current** | $I_{GT}$ | 200 mA | | **Junction Operating Temperature** | $T_J$ | -40°C to +125°C | --- ### 2. Physical and Mechanical Features These devices are engineered for heavy-duty environments: * **Package Type:** B-8 (Hockey Puk). * **Mounting:** Requires a specific clamping force (typically around 22.2 kN) to ensure optimal electrical and thermal contact between the device and the heat sink. * **Dual Cooling:** The flat design allows for double-sided cooling, significantly increasing the current-carrying capacity compared to stud-mount versions. --- ### 3. Functional Operation The VS-ST1280C..K operates as a controlled switch: 1. **Forward Blocking:** The device remains off even when a forward voltage is applied. 2. **Triggering:** When a small pulse is applied to the **Gate**, the device latches into a conducting state. 3. **Conduction:** It continues to conduct as long as the current remains above the "holding current" level. 4. **Turn-off:** It turns off only when the current drops to zero or the polarity is reversed (natural commutation). --- ### 4. Common Applications Due to their high power handling, these parts are used in: * **DC Motor Controls:** Speed and torque regulation for large industrial motors. * **Power Supplies:** Large scale battery chargers and electrochemical plating. * **AC Switches:** Solid-state contactors for heavy resistive or inductive loads. * **Soft Starters:** Reducing inrush current in three-phase motors. --- ### 5. Part Number Identification The suffix letters and numbers define specific voltage ratings: * **VS-ST1280C04K:** 400V Repetitive Peak Voltage. * **VS-ST1280C06K:** 600V Repetitive Peak Voltage.