## Technical Overview: STK-RPS-150PS The **STK-RPS-150PS** is a modular power supply unit (PSU) primarily designed for Cisco StackWise and specific Catalyst switch series (such as the 3750-E and 3560-E). It serves as a redundant power source to ensure network uptime in case of internal power failure. ### Core Specifications | Feature | Specification | | :--- | :--- | | **Model Number** | STK-RPS-150PS | | **Power Output** | 150 Watts | | **Input Voltage** | 100 to 240 VAC (Auto-ranging) | | **Frequency** | 50 to 60 Hz | | **Form Factor** | Hot-swappable Plug-in Module | | **Compatibility** | Cisco Catalyst 3750-E, 3560-E Series | --- ### Internal Electronic Components & Design The STK-RPS-150PS utilizes a **Switching Mode Power Supply (SMPS)** architecture. Below are the key electronic sections: #### 1. Input Rectification and Filtering * **EMI Filter:** Includes inductors and X/Y capacitors to suppress electromagnetic interference and prevent noise from returning to the AC line. * **Bridge Rectifier:** Converts AC input into high-voltage DC. #### 2. Power Factor Correction (PFC) * To meet industrial efficiency standards, it likely includes an active PFC circuit (controlled by an IC and a MOSFET) to ensure the current waveform matches the voltage waveform, maximizing power efficiency. #### 3. DC-to-DC Conversion (The Switching Stage) * **PWM Controller:** A Pulse Width Modulation chip regulates the switching frequency of power MOSFETs. * **High-Frequency Transformer:** Provides galvanic isolation and steps down the high-voltage DC to the lower voltages required by the switch logic. #### 4. Output Stage and Monitoring * **Schottky Diodes/Synchronous Rectifiers:** Used for efficient DC rectification on the output side. * **Protection Circuits:** * **OVP (Over Voltage Protection):** Shuts down the unit if the output exceeds safe limits. * **SCP (Short Circuit Protection):** Prevents damage if the output is grounded. * **OTP (Over Temperature Protection):** Thermal sensors monitor the internal heatsinks. --- ### External Interface * **Front Panel LED:** Provides status indication (Green for "OK", Amber for "Fault"). * **Hot-Swap Connector:** A high-density blind-mate connector on the rear that facilitates the connection to the switch's power backplane without powering down the device. ---