The part number **4-356-R** is generally associated with a specific series of **Current Sense Transformers** manufactured by companies like **Talema** or **Nuvotem**. These components are critical in power electronics for monitoring current levels without breaking the circuit. --- ### 1. Technical Specifications Below are the typical specifications for the 4-356-R model (Commonly the AS Series): | Parameter | Value | | :--- | :--- | | **Component Type** | Current Sense Transformer | | **Turns Ratio** | 1:50 | | **Primary Current (Max)** | 10A to 15A (Typical) | | **Frequency Range** | 20 kHz - 200 kHz | | **Termination Resistance** | ~50 Ohms (Recommended) | | **Package Style** | Through-hole (PCB Mount) | | **RoHS Status** | Compliant (Indicated by the "R" suffix) | --- ### 2. Functional Purpose Current sense transformers act as transducers. They produce an AC current in their secondary winding that is proportional to the AC current flowing through the primary conductor. * **Isolation:** They provide galvanic isolation between high-power circuits and low-voltage control circuits. * **Measurement:** By placing a "burden resistor" across the secondary leads, the current is converted into a measurable voltage for a Microcontroller or ADC. * **Efficiency:** They have very low insertion loss compared to shunt resistors. --- ### 3. Key Features 1. **Compact Footprint:** Designed for high-density PCB layouts. 2. **Encapsulated Construction:** Usually potted in resin for environmental protection and high dielectric strength. 3. **Frequency Optimized:** Built using ferrite cores that perform best in high-frequency switching power supplies (SMPS). --- ### 4. Typical Applications * **Overload Sensing:** Protecting power supplies from short circuits. * **Switching Power Supplies:** Feedback loops for current-mode control. * **Motor Control:** Monitoring phase currents in small AC motors. * **Lighting Ballasts:** Current regulation in electronic ballasts. --- ### 5. Wiring Diagram Concept To use the 4-356-R, you typically route the main current line through the center hole (or primary pins) and connect the secondary output as follows: ```text [Primary Side] ---- ( Transformer ) ---- [Load] | [Secondary Pins] | +------+------+ | | [Burden Resistor] [ADC/Scope] | | GND GND ```