The **ST380CH..C** series refers to a family of high-power **Phase Control Thyristors** (Silicon Controlled Rectifiers) manufactured by Vishay (formerly International Rectifier). These devices are designed for heavy-duty industrial switching and power conversion. --- ### 1. Key Technical Specifications These thyristors are characterized by their high current handling capacity and robust "TO-200AC" (B-PUK) housing. | Parameter | Typical Value | Description | | :--- | :--- | :--- | | **$I_{T(AV)}$** | 380 A | Maximum average on-state current | | **$V_{DRM} / V_{RRM}$** | 400V to 600V | Peak repetitive off-state and reverse voltage | | **$I_{TSM}$** | ~5000 A to 5500 A | Peak non-repetitive surge current (50/60Hz) | | **$V_{TM}$** | ~1.6 V | Maximum peak on-state voltage drop | | **Package** | TO-200AC (B-PUK) | "Hockey Puk" press-fit ceramic housing | --- ### 2. Physical Construction (The "Hockey Puk") The "C" suffix in the part number denotes a **Ceramic** press-pack package. Unlike standard TO-220 or TO-247 components, these do not have leads. * **Mounting:** They must be clamped between two heatsinks under specific pressure (measured in kilonewtons, kN). * **Cooling:** This design allows for **double-sided cooling**, significantly increasing the power density. * **Isolation:** The ceramic body provides high electrical isolation between the anode and cathode. --- ### 3. Electrical Functionality As a **Phase Control Thyristor**, the ST380CH acts as a controlled switch: 1. **Blocking State:** It blocks voltage in both directions until a pulse is applied to the Gate. 2. **Triggering:** A small current pulse at the Gate ($I_{GT}$) turns the device ON. 3. **Conduction:** Once ON, it stays ON even if the Gate signal is removed, provided the current remains above the "holding current" level. 4. **Turn-off:** It only turns OFF when the current flowing through it drops to zero (Natural Commutation), which typically happens at the end of an AC half-cycle. --- ### 4. Common Applications Due to their high reliability and current capacity, they are found in: * **DC Motor Drives:** Controlling the speed of large industrial motors. * **Battery Chargers:** High-current industrial charging stations. * **Welding Equipment:** Power regulation for arc welding. * **AC Soft Starters:** Reducing inrush current in large machinery. * **Phase-Controlled Rectifiers:** Converting AC to DC with variable output voltage. --- ### 5. Identification Coding * **ST:** Semiconductor Thyristor. * **380:** Average current rating ($I_{T(AV)}$). * **CH:** High voltage/Standard speed series. * **04/06:** Voltage code (e.g., `04` = 400V, `06` = 600V). * **C:** Ceramic "Puk" package.