## FTR-K3JB018W-LS: Electronic Component Overview The **FTR-K3JB018W-LS** is a specific type of **electromechanical power relay** manufactured by Fujitsu. It is designed for high-current switching applications, commonly found in power supplies and industrial equipment. --- ### 1. Key Technical Specifications The following table summarizes the primary electrical and physical characteristics of the component: | Feature | Specification | | :--- | :--- | | **Component Type** | Electromechanical Power Relay | | **Coil Voltage** | 18V DC | | **Contact Form** | 1 Form A (SPST-NO: Single Pole Single Throw, Normally Open) | | **Contact Rating** | 25A (Resistive Load) | | **Switching Voltage** | Max 250V AC / 30V DC | | **Terminal Type** | PCB Mounting (Through-hole) | | **Insulation** | High insulation (Reinforced insulation between coil and contacts) | | **Creepage/Clearance** | Minimum 8.5mm / 8.0mm | --- ### 2. Functional Components To understand how this part works, it can be broken down into three main electronic sections: #### A. The Coil (Input Side) * **Voltage:** Operates on an 18V DC signal. * **Function:** When 18V is applied, current flows through the copper winding, creating an electromagnetic field that pulls the internal armature. * **Protection:** In a circuit, this usually requires a "Flyback Diode" (e.g., 1N4148) in parallel to prevent voltage spikes when the relay is de-energized. #### B. The Contacts (Output Side) * **Material:** Often silver-alloy based to handle high inrush currents. * **Load Handling:** Capable of switching up to 25 Amps. This makes it suitable for heavy loads like heaters, motors, or power inverters. * **High-Inrush Support:** The "LS" suffix typically denotes a version designed to handle high-surge currents, such as those caused by capacitive loads. #### C. Insulation and Housing * **Dielectric Strength:** Designed to withstand high voltage surges (up to 10kV) between the coil and the contacts. * **Sealing:** Usually comes in a "Flux Proof" or "Plastic Sealed" enclosure to prevent contamination during the soldering process on a PCB. --- ### 3. Common Applications * **Photovoltaic Systems:** Used in solar inverters for grid connection and safety disconnection. * **EV Charging:** Power switching in Level 1 or Level 2 AC chargers. * **Home Appliances:** High-power units like washing machines or air conditioners. * **Industrial Automation:** Controlling high-current actuators. ---