The **GMA-63-R** is a specific model of a glass tube fuse, commonly used in electronic circuits for overcurrent protection. Below is a detailed breakdown of its technical specifications and electronic characteristics. --- ### 1. Technical Specifications | Feature | Specification | | :--- | :--- | | **Part Number** | GMA-63-R | | **Fuse Type** | Glass Tube (Cartridge) | | **Current Rating** | 63mA (0.063 Amps) | | **Voltage Rating** | 250V AC | | **Response Time** | Fast-Acting (Fast Blow) | | **Dimensions** | 5mm x 20mm | | **Termination Style** | Cartridge (Clip-in) | | **Compliance** | RoHS Compliant (The "-R" suffix) | --- ### 2. Key Electronic Components & Materials The GMA-63-R consists of four primary physical parts that define its electronic behavior: 1. **The Fuse Element (Wire):** A very thin metallic wire designed to melt when the current exceeds 63mA. In "Fast-Acting" fuses like this one, the wire is designed to break almost instantly without a delay mechanism. 2. **The Glass Body:** Provides an insulating housing that allows for visual inspection. You can see if the internal wire is broken (blown). 3. **End Caps:** Made of nickel-plated brass. These provide the electrical contact points between the circuit holder and the fuse element. 4. **Extinguishing Medium:** While some high-voltage fuses contain sand, the GMA series is typically air-filled, relying on the gap created by the melted wire to stop the arc. --- ### 3. Functional Behavior * **Overload Protection:** This fuse is rated at a very low current (63mA), making it ideal for protecting sensitive low-power electronics, such as control circuits, multimeters, or fine instrumentation. * **Fast-Acting Characteristic:** Unlike a "Slow-Blow" (Time-Delay) fuse, the GMA-63-R does not tolerate temporary current surges. If the current spikes above the threshold even for a few milliseconds, the circuit will open. * **Interrupting Rating:** This refers to the maximum current the fuse can safely stop without physically exploding. For the GMA series at 250V AC, this is typically around 35A to 100A depending on the specific manufacturer (e.g., Eaton/Bussmann). --- ### 4. Application Context The "GMA" designation is a standard industry size and speed. You will frequently find these in: * Small power supplies. * Laboratory equipment. * Consumer electronics (older audio/video gear). * Testing and measurement devices.