What is a dynamite fuse made of?
The last layer is a low-nitrate nitrocellulose lacquer that keeps the fuse from falling apart. The last layer helps to make the visco fuse water resistant and to prevent moisture from degrading the black powder core. Unlike dynamite safety fuse, visco fuse burns with a visible external flame.
Most LV fuse elements are made of copper (Cu). Fuse elements of fast acting fuses and HV fuses are primarily made of silver (Ag). Silver plated copper is also commonly used. As a rule, fuse elements of time delay fuses contain low melting point materials, e.g. tin (Sn) or zinc (Zn) and alloys thereof.
- The material used for fuse elements must be of low melting point, low ohmic loss, high conductivity (or low resistivity), low cost and free from detraction. The material used for making fuse element has a low melting point such as tin, lead, or zinc.
- The function of a fuse is usually to prevent fire - that's the basic protection a fuse offers - between power supply and appliance there may be a few feet or metres of cable - if a short circuit occurs in the appliance, the cable could easily become overheated (due to excess current) and burn or rupture its insulation.
- Its essential component is a metal wire or strip that melts when too much current flows through it, thereby interrupting the current. It is a sacrificial device; once a fuse has operated it is an open circuit, and it must be replaced or rewired, depending on type.
A visco fuse has a core of black powder with one or more textile overwraps. The outer layers may be coated with wax or nitrocellulose lacquer for water resistance. These fuses are widely used in modern pyrotechnics because they burn at a uniform rate, with an easily visible external flame.
- The fuse breaks the circuit if a fault in an appliance causes too much current flow. This protects the wiring and the appliance if something goes wrong. The fuse contains a piece of wire that melts easily. If the current going through the fuse is too great, the wire heats up until it melts and breaks the circuit.
- The terms “open” and “closed” refer to switches as well as entire circuits. An open switch is one without continuity: electrons cannot flow through it. A closed switch is one that provides a direct (low resistance) path for electrons to flow through.
- An ammeter is a measuring device used to measure the electric current in a circuit. A voltmeter is connected in parallel with a device to measure its voltage, while an ammeter is connected in series with a device to measure its current.
A fuse is a small, thin conductor designed to melt and separate into two pieces for the purpose of breaking a circuit in the event of excessive current. A circuit breaker is a specially designed switch that automatically opens to interrupt circuit current in the event of an overcurrent condition.
- A fuse rating is the current need to blow (break) the fuse. When a fuse has blown it removes electrical power from an electrical circuit. The fuse rating is usually on the side of the fuse. Thefuse rating is usually defined in 'amps' – amps are the unit of measurement of electrical current.
- Fuses and circuit breakers are designed to interrupt the power to a circuit when the current flow exceeds safe levels. As such, fuses and breakers are primarily intended to protect the wiring -- UL or CSA approval indicates that the equipment itself should not cause a fire.
- An electronic fuse is a low resistance resistor that provides protection in the event of a load overcurrent. Short circuits, device failure or overloading can cause a load overcurrent. In an electronic fuse, a metal wire melts in the event of an overcurrent, therefore causing an interruption in the circuit.
Updated: 12th November 2019