The **MJS 150-R TR** is a specific part number for a **Micro Fuse** manufactured by Bel Fuse Inc. It belongs to the MJS series, which are radial-leaded, subminiature, slow-blow (time-delay) fuses designed for space-constrained circuit protection. --- ### 1. Technical Specifications The part number breaks down into specific electrical and physical characteristics: | Feature | Specification | | :--- | :--- | | **Series** | MJS (Micro Jack Series) | | **Amperage Rating** | 150mA (0.150 Amps) | | **Voltage Rating (AC)** | 250V | | **Response Characteristic** | Time-Delay / Slow-Blow (TR) | | **Body Material** | Glass or Ceramic Tube | | **Mounting Type** | Through-Hole (Radial Leads) | | **Interrupting Rating** | 35A @ 250V AC / 10,000A @ 125V AC | --- ### 2. Part Number Breakdown Understanding the suffix "TR" and the prefix "MJS" is essential for procurement and PCB design: * **MJS**: Indicates the subminiature radial fuse family. These are often called "pigtail" fuses because of the wire leads. * **150**: Represents the current rating (150mA). * **-R**: Typically indicates **RoHS Compliance**, meaning the part is lead-free and environmentally regulated. * **TR**: Stands for **Tape & Reel** packaging, signifying the part is supplied on a continuous strip for automated pick-and-place or insertion machines. --- ### 3. Key Applications Because of its slow-blow nature and small footprint, this component is commonly used in: * **Power Supplies:** Protecting against nuisance blowing caused by inrush currents. * **Chargers:** Small adapters for consumer electronics. * **Industrial Controls:** Protecting sensitive PCB-mounted components. * **Telecom Equipment:** Used where high voltage protection is needed in a small form factor. --- ### 4. Why use a "Slow-Blow" (Time-Delay) Fuse? The **MJS 150-R TR** is designed to tolerate temporary current surges (such as when a device first powers on) without blowing. However, if a sustained overcurrent condition occurs, the fuse will open the circuit to prevent fire or further component damage. --- ### 5. Physical Dimensions (Approximate) | Dimension | Value | | :--- | :--- | | **Diameter** | ~4.6 mm | | **Length** | ~11.0 mm | | **Lead Spacing** | ~5.08 mm (Standard radial pitch) | ---