The **GMD-1.25-R** is a specific type of electronic component, primarily classified as a **Time-Delay Glass Tube Fuse**. It is manufactured by Eaton (formerly Bussmann) and belongs to the GMD series. --- ### 1. Key Technical Specifications The following table outlines the electrical and physical characteristics of the GMD-1.25-R: | Feature | Specification | | :--- | :--- | | **Current Rating** | 1.25 Amperes (1.25A) | | **Voltage Rating (AC)** | 250 Volts | | **Fuse Type** | Time-Delay (Slow-Blow) | | **Body Material** | Glass Tube | | **Dimensions** | 5mm x 20mm | | **Interrupt Rating** | 100A at 250Vac | | **RoHS Compliant** | Yes (indicated by the "-R" suffix) | --- ### 2. Deep Dive into Component Parts #### A. The Fuse Element The internal wire is engineered to be a **Time-Delay (T)** element. Unlike "Fast-Acting" fuses that blow instantly upon reaching the threshold, the GMD-1.25-R allows for temporary "inrush" currents. This is crucial for inductive loads like motors or power supplies that draw a high initial current. #### B. The Housing (Glass Tube) The transparent glass body allows for easy visual inspection. If the fuse has blown due to a massive short circuit, the glass may appear charred; if it was a slow overcurrent, the wire may simply be broken. #### C. End Caps The metal end caps are nickel-plated brass. These ensure high conductivity and a secure fit into fuse clips or holders. #### D. The "-R" Suffix In the Eaton/Bussmann catalog, the **-R** indicates that the part is lead-free and complies with **RoHS** (Restriction of Hazardous Substances) standards. --- ### 3. Common Applications Due to its 1.25A rating and slow-blow characteristics, this fuse is commonly found in: * **Power Supplies:** Protecting the input stage from surges. * **Consumer Electronics:** Used in CRT monitors, audio amplifiers, and household appliances. * **Industrial Controls:** Protecting small control transformers. --- ### 4. Safety and Replacement When replacing a GMD-1.25-R, ensure the replacement matches: 1. **Amperage:** Must be exactly 1.25A. 2. **Speed:** Must be "Time-Delay" (marked as 'T' or 'Slo-Blo'). Do not replace with a Fast-Acting fuse, as it will likely blow immediately upon startup. 3. **Voltage:** The replacement must be rated for at least 250V.