Patent Application
20100164677
1. Field of Invention
The present invention relates to a fuse, and more particularly to a fuse having multiple high density conductive alloy wires.
2. Description of the Related Art
Electronic apparatuses are integrated into daily life and generally comprise a fuse for safety. Different fuses are installed inside electronic apparatuses or connecting boxes for protecting the electronic apparatuses and power wire network.
With reference to
However, since most present consumer electronic products are low power and low current, the conventional fuse (90) is unable to protect the present consumer electronic products because the conventional fuse (90) is not sensitive enough to be melted.
The conventional fuse (90) has a long response time, low sensitivity to input current, is environmental temperature dependent, wasteful of power required for heating the heating resistor (92), capable of causing heating resistor (92) damage, has limited installation positions, and after a blowout current may leak through residual molten conventional low temperature melting fuse (91) as detailed below.
Under current electrical apparatus conditions, the conventional fuse (90) is rarely operated under an operation current lower than 12A. Although the operation current of the conventional fuse (90) is defined at 12A, 24A are required for heating the resistor (92) to melt the low temperature melting fuse (91).
With further reference to
Once the heating resistor (92) is damaged by an overloaded input power, the conventional fuse (90) is fail and is no longer able to protect the circuit loop and apparatuses.
After being heated, the low temperature melting fuse (91) is molten so installation position and attitude of the conventional fuse (90) is limited to prevent a molten low temperature melting fuse (91) damaging the circuit loop.
A melting time dependents on input voltage as shown in
Since the conventional low temperature melting fuse (91) is melted, a performance is temperature dependent, so current decay rate changes by nearly 50 wt % over a temperature range of 25 to 80° C., therefore the low temperature melting fuse (91) will be melted rapidly under high temperatures.
When the heating resistor (92) is heated to 135° C., over 1 min is required to melt the low temperature melting fuse (91), however, a PCB board near the heating resistor (92) may also be melted under such temperature.
A response time of the heating resistor (92) of the conventional fuse (90) is 0.3 sec to 4.5 sec, which is not fast enough to protect the circuit loop.
The present invention provides a fuse to obviate or mitigate the shortcomings of the conventional fuse.
The primary objective of the present invention is to provide a fuse having multiple high density conductive alloy wires.
A fuse has a base and multiple wires. The base is an insulator and has a top surface and multiple contact plates. The contact plates are mounted separately on the top surface of the base. The wires are high density conductive alloy comprising Al 60˜90 wt %, Mg 22˜30 wt %, Si 1˜3 wt % and Cu 1˜3 wt % and connect the contact plates in series. Since the wires are directly heated, response time, sensitivity, power waste and heating resistor damage problems associated with conventional fuses are solved and because the wires are high density conductive alloy that is nearly independent of environmental temperature, temperature dependency, installation position limitation and leakage current problems associated with conventional fuses are also solved. Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
With reference to
The base (10) is an insulator, may be a printed circuit board, a bakelite resin broad or the like and has a top surface and multiple contact plates (14) and may have an edge and multiple connection recesses.
With further reference to
The wires (20) are high density conductive alloy having a same length and thickness and comprise Aluminum (Al) 60˜90 wt %, Magnesium (Mg) 22˜30 wt %, Silicon (Si) 1˜3 wt %, Copper (Cu) 1˜3 wt % and may comprise impurities and connect the contact plates (14) in series. The thickness of the wires (20) may be less than 2 mm for preventing a residual conductive material generated by the melted wire (20). Multiple wires (20) may connect two adjacent contact plates (14) and two wires (20) may parallelly connect two adjacent contact plates (14) to prevent a native defect of one wire (20) causing a failure.
With further reference to
When connected to the circuit loop, input current form the circuit loop flows through the wires (20) and heats up the wires (20). The wires (20) blowout if the input current is beyond a loading limit. Because the wires (20) are directly heated, response time, sensitivity, power waste and heating resistor damage problems associated with conventional fuses are solved. Because the wires (20) are high density conductive alloy that is nearly independent of environmental temperature, the temperature dependency, installation position limitation and leakage current problems associated with conventional fuses are also solved.
With further reference to
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
