The **NET-35C** is a triple-output switching power supply manufactured by Mean Well. It is widely used in industrial automation, telecommunications, and hobbyist electronics due to its compact size and high reliability. --- ## 1. Technical Specifications The NET-35C is designed to convert AC line voltage into three distinct DC outputs. | Parameter | Specification | |:---|:---| | **Input Voltage Range** | 85 ~ 264 VAC / 120 ~ 370 VDC | | **Output 1 (V1)** | +5V DC @ 0.5 ~ 4.0A | | **Output 2 (V2)** | +15V DC @ 0.1 ~ 1.0A | | **Output 3 (V3)** | -15V DC @ 0.1 ~ 0.5A | | **Total Rated Power** | 35 Watts | | **Efficiency** | 76% | | **Cooling** | Free air convection | --- ## 2. Key Electronic Components & Internal Design The device operates on a **Pulse Width Modulation (PWM)** control circuit. Below are the primary electronic sections: ### A. Input Filter & Protection * **EMI Filter:** Includes X and Y capacitors and a common-mode choke to suppress electromagnetic interference. * **Thermistor (NTC):** Used for inrush current limiting to protect components during power-up. * **Fuse:** Standard protection against short circuits or over-current at the AC input. ### B. Power Conversion Stage * **Bridge Rectifier:** Converts AC to high-voltage DC. * **Bulk Capacitor:** Smooths the rectified DC before it enters the switching stage. * **Switching MOSFET:** High-speed transistor that "chops" the DC into high-frequency AC for the transformer. * **Transformer:** A multi-tap ferrite transformer that steps down the voltage and provides galvanic isolation between input and output. ### C. Output Rectification & Filtering * **Schottky Diodes:** Used on the output side for fast rectification with low forward voltage drop. * **Electrolytic Capacitors:** Low ESR (Equivalent Series Resistance) capacitors are used to filter ripple and noise from the DC outputs. --- ## 3. Terminal Pin Assignment The NET-35C typically features a 7-pin screw terminal block for connections: | Pin No. | Assignment | Description | |:---:|:---|:---| | 1 | AC/L | AC Line (Hot) | | 2 | AC/N | AC Neutral | | 3 | FG | Frame Ground | | 4 | V3 | -15V Output | | 5 | V2 | +15V Output | | 6 | COM | Common Ground (Return) | | 7 | V1 | +5V Output | --- ## 4. Protection Features The internal circuitry includes several safety mechanisms: 1. **Overload Protection:** Typically 110% to 150% of rated output power; uses "hiccup mode" (recovers automatically after fault is removed). 2. **Overvoltage Protection:** Specifically for the 5V output (usually trips between 5.75V and 6.75V). 3. **Short Circuit Protection:** Protects the unit if any output rail is grounded.