The **GMA-1-R** is a specific model of a fast-acting glass tube fuse manufactured by Eaton (formerly Bussmann). It is widely used in electronic equipment to protect circuits from overcurrent conditions. --- ### ## Technical Specifications The following table outlines the primary electrical and physical characteristics of the GMA-1-R: | Parameter | Specification | | :--- | :--- | | **Current Rating** | 1 Ampere | | **Voltage Rating (AC)** | 250 VAC | | **Fuse Type** | Fast-Acting / Quick-Acting (F) | | **Material** | Glass Body, Nickel-plated Brass Endcaps | | **Dimensions** | 5mm x 20mm (Standard Small Cartridge) | | **Interrupt Rating** | 35A @ 250VAC / 10,000A @ 125VAC | | **RoHS Compliant** | Yes (indicated by the "-R" suffix) | --- ### ## Component Breakdown ### 1. The Glass Body The transparent glass housing allows for visual inspection. If the fuse has "blown" due to a short circuit or overload, you can often see a broken wire or a dark smudge inside the tube. ### 2. The Wire Element As a **Fast-Acting** fuse, the internal element is designed to melt almost instantly when the current exceeds 1A. Unlike "Slow-Blow" (Time-Delay) fuses, the GMA-1-R does not tolerate temporary surges, making it ideal for protecting sensitive semiconductor components. ### 3. Suffix Meanings * **GMA**: Represents the series (5x20mm, fast-acting). * **1**: Represents the amperage (1 Amp). * **-R**: Indicates **RoHS compliance**, meaning the part is manufactured without hazardous substances like lead. --- ### ## Common Applications The GMA-1-R is typically found in the following electronic environments: * **Consumer Electronics:** Power supplies for laptops, printers, and monitors. * **Audio/Video Gear:** Amplifiers and signal processors. * **Test Equipment:** Multimeters and oscilloscopes. * **Control Boards:** Small industrial PLCs and circuit boards where space is limited. --- ### ## Comparison: Fast-Acting vs. Time-Delay It is critical not to swap a GMA (Fast-Acting) fuse with a GDC (Time-Delay) fuse of the same rating. | Feature | GMA-1-R (Fast-Acting) | GDC-1-R (Time-Delay) | | :--- | :--- | :--- | | **Reaction Time** | Immediate | Delayed | | **Inrush Tolerance** | Very Low | High | | **Best For** | Protecting ICs/Sensitive Parts | Protecting Motors/Transformers |