The **NET-35D** is a specialized electronic component primarily categorized as an **AC-DC Switching Power Supply (Open Frame)**. It is widely used in industrial automation, networking equipment, and telecommunications due to its multi-output capability and compact design. Below is a detailed breakdown of its electronic specifications and internal parts. --- ## 1. Core Technical Specifications The NET-35D is designed to convert high-voltage AC input into multiple low-voltage DC outputs. | Parameter | Specification | | :--- | :--- | | **Input Voltage Range** | 85 ~ 264VAC / 120 ~ 370VDC | | **Total Rated Power** | 35 Watts | | **Output 1 (CH1)** | +5V / 0.5 ~ 4.0A | | **Output 2 (CH2)** | +12V / 0.1 ~ 1.5A | | **Output 3 (CH3)** | +24V / 0.1 ~ 1.0A | | **Efficiency** | ~78% | | **Cooling** | Free air convection | --- ## 2. Internal Electronic Parts and Functions The unit is composed of several critical stages typical of a Switch Mode Power Supply (SMPS): ### A. Input Filter & Rectification * **Bridge Rectifier:** Converts incoming AC voltage to a high-voltage pulsating DC. * **EMI Filter (Inductors & X/Y Capacitors):** Suppresses electromagnetic interference to comply with global standards (like EN55022). * **NTC Thermistor:** Limits "inrush current" when the device is first powered on to protect the internal components. ### B. Switching Stage * **PWM Controller IC:** The "brain" of the unit. It modulates the pulse width to maintain a stable output voltage despite variations in load or input. * **Power MOSFET:** A high-speed transistor that "switches" the DC voltage at high frequencies (typically 50kHz - 100kHz) into the transformer. ### C. Power Transformation * **Ferrite Core Transformer:** Provides galvanic isolation between the high-voltage input and low-voltage output. It has multiple secondary windings to produce the 5V, 12V, and 24V rails. ### D. Output Rectification & Filtering * **Schottky Diodes:** Used for high-speed rectification of the high-frequency AC coming off the transformer. * **Electrolytic Capacitors:** Low-ESR (Equivalent Series Resistance) capacitors that smooth the DC ripples. * **Output Chokes (Inductors):** Work with capacitors to form an LC filter for clean DC power. --- ## 3. Protection Circuits The NET-35D includes active electronic protection to prevent damage to the connected load: 1. **Overload Protection:** Usually triggers at 105% ~ 150% of rated output power; uses "hiccup mode" (recovers automatically after fault is removed). 2. **Overvoltage Protection:** Specifically for the 5V rail (typically trips at 5.75V ~ 6.75V) to protect logic circuits. 3. **Short Circuit Protection:** Shuts down the output if a direct short is detected. --- ## 4. Connection Interface The board typically utilizes a **Molex-style pin header** or **Terminal Block**: * **Input (CN1):** 3 Pins (Line, Neutral, Ground). * **Output (CN2):** 6-8 Pins (V1, V2, V3, and Common Grounds).