TW201807915A - Controllable circuit protector applicable to multiple power supply voltages wherein the total heating power is not drastically changed due to the voltage change of the power supply so that the first low-temperature metal fuse or the second low-temperature metal fuse are instantly fused to protect the load - Google Patents

Abstract

The present invention is related to a controllable circuit protector applicable to multiple power supply voltages, comprising a first low-temperature metal fuse, a second low-temperature metal fuse, a first heating unit, and at least one second heating unit, wherein the first low-temperature metal fuse and the second low-temperature metal fuse are connected in series, and the first heating unit and the at least one second heating unit are connected in parallel. The free end of the first low-temperature metal fuse is formed as an input end and the free end of the second-low temperature metal fuse is formed as an output end. One end of the first heating unit is electrically connected to a series contact of the first low-temperature metal fuse and the second low-temperature metal fuse, and a free end of the first heating unit is formed as a control terminal. The breaking capacity of the fuse of each of the at least one second heating unit is less than that of the first low-temperature metal fuse or the second low-temperature metal fuse. When a load is abnormal, a switch is turned on so that the control terminal is electrically connected to a ground terminal. At this time point, according to the voltage supplied by the power supply, all or a part of the at least one second heating unit are fused or all of the at least one second heating unit are not fused to change the equivalent resistance of the first heating unit connected in parallel and the not-fused portion of the at least one second heating unit. The total heating power is not drastically changed due to the voltage change of the power supply so that the first low-temperature metal fuse or the second low-temperature metal fuse are instantly fused to protect the load.

Description

Controllable circuit protector for various power supply voltages

The invention relates to a controllable circuit protector, in particular to a controllable circuit protector applicable to a variety of power supply voltages.

Please refer to FIG. 9, the general fuse device 40 includes an input terminal I / P4, an output terminal O / P4, a control terminal C4, a first temperature fuse 41, a second temperature fuse 42 and a heating resistor R4. The first temperature fuse 41 is connected in series with the second temperature fuse 42, and a series connection point of the first temperature fuse 41 and the second temperature fuse 42 is further electrically connected to one end of the heating resistor R4. The free end of the first temperature fuse 41 forms the input terminal I / P4, the free end of the second temperature fuse 42 forms the output terminal O / P4, and the free end of the heating resistor R4 forms the control terminal. C4.

When using the fuse device 40, the input terminal I / P4 is electrically connected to a power source 50, and the output terminal O / P4 is electrically connected to a load 60, and the control terminal C4 is electrically connected to a switch SW4 through a switch Ground terminal GND.

The switch SW4 is controlled to be disconnected or connected according to the state of the load 60. When the load 60 is in an abnormal state, the switch SW4 can be controlled to be connected, so that the free end of the heating resistor R4 is connected to the ground terminal GND. At this time, the electric power provided by the power source 50 starts to energize the heating resistor R4 and the temperature of the heating resistor R4 starts to rise, causing the first temperature fuse 41 or the second temperature fuse 42 to be blown.

The rate of temperature rise of the heating resistor R4 is determined by the heating power of the heating resistor R4 itself. When the temperature of the heating resistor R4 exceeds the temperature of the first temperature fuse 41 or the second temperature fuse 42, the first Only the thermal fuse 41 or the second thermal fuse 42 is blown. The heating power of the heating resistor R4 is calculated according to the following formula:

;

Among them, P is the heating power of the heating resistor R4, V is the voltage provided by the power source 50, and R is the resistance value of the heating resistor R4.

When the state of the load 60 is detected to be abnormal, the first temperature fuse 41 or the second temperature fuse 42 needs to be blown within a specific time to come and protect the load 60. Therefore, when the resistance value R of the heating resistor R4 is a fixed value, the melting time of the first temperature fuse 41 or the second temperature fuse 42 is related to the heating power P of the heating resistor R4. The higher the heating power P is, the shorter the melting time of the first temperature fuse 41 or the second temperature fuse 42 is, which is negatively correlated. The heating power P of the heating resistor R4 is positively related to the square of the voltage V provided by the power source 50. Therefore, the melting time of the first temperature fuse 41 or the second temperature fuse 42 is inversely related to the square of the voltage V provided by the power source 50.

That is, the larger the voltage V provided by the power source 50 is, the shorter the melting time of the first thermal fuse 41 or the second thermal fuse 42 is.

However, when the manufacturer of the fuse device 40 generally manufactures the fuse device 40, the same heating resistor R4 is used, that is, the resistance value R of the heating resistor R4 is a fixed value. Therefore, the fuse device 40 can only be applied to a power source 50 having a specific voltage value or more. When the voltage V of the power source 50 is less than the specific voltage value, it means that when the load 60 is abnormal, the switch SW4 is turned on, and the heating power P of the heating resistor R4 will be insufficient, causing the first temperature fuse 41 or the second temperature The fuse 42 is too long to be blown, or cannot be blown. The fuse 60 cannot be blown off immediately to protect the load 60, and the load 60 is affected and damaged.

For example, if the fuse device 40 manufactured by the manufacturer is suitable for a 220V power supply 50, it means that when the load 60 is abnormal, the switch SW4 is turned on, and the voltage V of the power supply 50 is 220V, so that the heating resistor R4 The heat is generated, so that the first temperature fuse 41 or the second temperature fuse 42 can be immediately blown. However, when the fuse device 40 is applied to a 110V power supply 50, it means that when the switch SW4 is turned on, the voltage V of the power supply 50 is 110V, so that the heating power of the heating resistor R4 is reduced, and the first temperature fuse 41 or the The melting time of the second temperature fuse 42 is increased, resulting in failure to immediately fuse or even fail to fuse, causing the load 60 to be abnormally damaged.

Therefore, the fuse device 40 manufactured by the manufacturer can only be applied to the 220V power supply 50 and cannot be applied to the 110V power supply 50. If the fuse device 40 is to be used at the 110V power supply 50, the manufacturer must redesign the fuse device 40 in the fuse device 40. The resistance value of the heating resistor R4 is used to remanufacture the fuse device 40. For the manufacturer of the fuse device 40, a dedicated fuse device 40 is developed for each power source with different voltages, and the manufacturing cost is relatively increased. The current power supply equipment operates at full voltage (90 ~ 260V) and cannot meet the current requirements. Therefore, the existing fuse device 40 cannot be used in AC and can only be used below DC 30V, so it is necessary to do further work. Improvement.

In view of the fact that the above-mentioned general fuse device can only be applied to a power supply with a specific voltage after the production is completed, different fuse devices need to be developed for different voltage power supplies, resulting in the disadvantage of increased manufacturer costs. The present invention provides a method applicable to multiple power supply voltages. Controllable circuit protector to apply to many different voltage power supplies. The controllable circuit protector applicable to various power supply voltages includes: a first low-temperature metal fuse; a second low-temperature metal fuse connected in series with the first low-temperature metal fuse; wherein the first low-temperature metal fuse The free end of the wire forms an input end, and the free end of the second low-temperature metal fuse forms an output end; a first heating unit, one end of which is electrically connected to the first low-temperature metal fuse and the second low-temperature The metal fuse is connected in series, and the free end of the first heating unit forms a control end; at least one second heating unit is connected in parallel with the first heating unit.

The low-temperature metal fuse device suitable for a variety of power supply voltages electrically connects the input terminal to a power source, the output terminal to a load, and the control terminal to a ground through a switch. end.

When the load is detected abnormally, the switch is controlled to be turned on, so that the control terminal is electrically connected to the ground terminal. At this time, the first heating unit and the at least one second heating unit connected in parallel form a loop with the power source and the first low-temperature metal fuse, and according to the magnitude of the voltage provided by the power source, all or part of the at least one A second heating unit will be fused to form an open circuit, or the at least one second heating unit will not be fused, so that the first heating unit is connected in parallel with the unfused part of the at least one second heating unit, thus changing The equivalent resistance values of the first heating unit and the at least one second heating unit that are not melted. Therefore, when the total heating power of the first heating unit and the at least one second heating unit that is not blown out is calculated according to the formula, the total heating power will follow the unheated part of the at least one second heating unit. The quantity changes. Therefore, when the voltage of the power source is changed, the equivalent resistance value will change accordingly, so that the total heating power will not change drastically due to the voltage change of the power source, and then the first low-temperature metal fuse or the second Low-temperature metal fuses can be instantly disconnected.

Since the number of the at least one second heating unit that is not melted is determined by the voltage of the power supply, the magnitude of the change in the total heating power with the voltage of the power supply will slow down, thereby making the controllable circuit protector applicable. For a variety of power supplies with different voltages, manufacturers' production costs are simplified.

In the following, the technical means adopted by the present invention to achieve the intended purpose will be further explained in conjunction with the drawings and the preferred embodiments of the present invention.

Please refer to FIG. 1, the present invention is a controllable circuit protector 10 suitable for a variety of power supply voltages, and suitable for a variety of power supplies with different voltages. The controllable circuit protector 10 suitable for various power supply voltages includes a first low-temperature metal fuse 11, a second low-temperature metal fuse 12, a first heating unit R1, and at least one second heating unit 131-13n.

The second low temperature metal fuse 12 is connected in series with the first low temperature metal fuse 11, and the free end of the first low temperature metal fuse 11 forms an input terminal I / P1, and the second low temperature metal fuse 12 The free end forms an output terminal O / P1. In the preferred embodiment, the first low-temperature metal fuse 11 and the second low-temperature metal fuse 12 are low-temperature alloy metal fuses.

One end of the first heating unit R1 is electrically connected to a series connection point of the first low-temperature metal fuse 11 and the second low-temperature metal fuse 12, and the free end of the first heating unit R1 forms a control terminal C1. . In the preferred embodiment, the first heating unit R1 is a heating resistor or a heater.

The at least one second heating unit 131 to 13n are respectively connected in parallel with the first heating unit R1. In the preferred embodiment, each of the at least one second heating unit 131 to 13n includes a second heating element R131 to R13n and a fuse 141 to 14n, and the second heating element R131 to R13n is connected to the fuse. 141 ~ 14n are connected in series. In the preferred embodiment, the second heating elements R131 to R13n are a heating resistor or a heater. In the preferred embodiment, the cut-off capacity of the fuses 141 to 14n of each of the at least one second heating unit 131 to 131n, that is, the degree of current resistance, is smaller than that of the first low temperature metal fuse 11 or the second low temperature metal Fuse 12. In addition, the cut-off capacities of the fuses 141 to 14n of the at least one second heating unit 131 to 131n are different from each other.

When the controllable circuit protector 10 suitable for various power voltages is used, the input terminal I / P1 is electrically connected to a power source 20, and the output terminal O / P1 is electrically connected to a load 30. The control terminal C1 of the first heating unit R1 is connected to a ground terminal GND through a switch electrical connection SW1.

The first low-temperature metal fuse 11 and the second low-temperature metal fuse 12 are directly connected between the power source 20 and the load 30. Therefore, when the voltage provided by the power source 20 is abnormal, the first low-temperature metal fuse 11 or the second low-temperature metal fuse 12 will directly fuse due to the abnormal voltage provided by the power source 20 to protect the load 30. It is not affected by the abnormal voltage provided by the power source 20. Therefore, the first low-temperature metal fuse 11 and the second low-temperature metal fuse 12 also have the same function as a general simple fuse.

When the load 30 is detected as abnormal, no matter whether the voltage provided by the power source 20 is abnormal, a control command is generated to turn on the switch SW1, and the control terminal C1 is electrically connected to the ground terminal GND. At this time, the first heating unit R1 and the at least one second heating unit 131 to 13n connected in parallel form a loop with the power source 20 and the first low-temperature metal fuse 11, and according to the magnitude of the voltage provided by the power source 20 All or part of the fuses 141 to 14n in the at least one second heating unit 131 to 13n will be blown to form an open circuit, or all of the at least one second heating unit 131 to 13n will not be blown, so that the The first heating unit R1 is connected in parallel with the unfused part of the at least one second heating unit 131 ~ 13n, thus changing the parallel connected first heating unit R1 and the unfused part of the at least one second heating unit 131 ~ 13n equivalent resistance. Therefore, when the total heating power of the first heating unit R1 and the second heating units 131 to 13n is calculated according to the formula, since the total heating power is calculated based on the equivalent resistance value and the voltage of the power supply 20, the total The heating power is changed according to the number of the second heating units 131 to 13n that are not melted. Therefore, when the voltage of the power supply 20 is changed, the equivalent resistance value will be changed accordingly, so that the total heating power will not be changed drastically due to the voltage change of the power supply 20, so that the first low-temperature metal fuse 11 or The second low-temperature metal fuse 12 can be instantly disconnected.

In addition, since the cut-off capacity of the fuses 141 to 14n of each of the at least one second heating unit 131 to 131n is smaller than that of the first low temperature metal fuse 11 or the second low temperature metal fuse 12. Even if the first low-temperature metal fuse 11 or the second low-temperature metal fuse 12 has not been fused because the voltage provided by the power source 20 is not abnormal, each of the at least one second heating unit 131 is turned on when the switch SW1 is turned on. Some of the ~ 131n fuses 141 ~ 14n will blow first. After the first heating unit R1 and the second heating units 13 are turned on and start to increase the temperature, the first low temperature metal fuse 11 or the second low temperature metal fuse 12 will be the first heating unit R1 and the The heat provided by the second heating unit 13 is fused to protect the load 30.

That is, through the design of the present invention, when the load SW30 is abnormally turned on by the load 30, the fuses 141 to 14n in the at least one second heating unit 131 to 13n are determined to be blown according to the voltage of the power source 20 first. Quantity, thereby changing the equivalent resistance of the first heating unit R1 in parallel and the second heating unit 131 ~ 13n of the unfused part, further changing the heating power to avoid the first low temperature metal fuse 11 or The melting time of the second low-temperature metal fuse 12 changes with the voltage value of the power source 20.

In summary, since the number of the at least one second heating unit 131 to 13n is turned on after the switch SW1 is turned on, the number of the at least one second heating unit 131 to 13n to be fused is determined according to the voltage of the power supply 20, The equivalent resistance values of the first heating unit R1 and the at least one second heating unit 131 to 13n that are not blown out are changed with the voltage of the power supply 20, so the total heating power varies with the voltage of the power supply 20. The amplitude will slow down, so that the controllable circuit protector 10 can be applied to a variety of power sources with different voltages, which saves manufacturers' manufacturing costs.

For example, as shown in FIG. 2 and FIG. 3, the number of the second heating units 131 to 13n is one, the resistance value of the first heating unit R1 is 910Ω, and the second value of the second heating unit 131 is 910Ω. The heating element R131 is 300Ω.

As shown in FIG. 2, when the controllable circuit protector 10 of various power supply voltages is suitable for an environment where the voltage value of the power supply 20 is 110V, and when the load 30 abnormally causes the switch SW1 to be turned on, the second heating unit The fuse 141 in 131 will not blow, so the equivalent resistance and the total heating power are calculated according to the following two formulas:

;

;

The equivalent resistance of the first heating unit R1 and the second heating unit 131 in parallel is 225.61Ω, and the total heating power is calculated according to the formula to be 53.63W.

As shown in FIG. 3, when the controllable circuit protector 10 of various power supply voltages is suitable for an environment where the voltage value of the power supply 20 is 220V, and when the load 30 abnormally turns on the switch SW1, the second heating The fuse 141 in the unit 131 is blown, so the equivalent resistance and the total heating power are calculated according to the following two formulas:

The equivalent resistance of the first heating unit R1 and the second heating unit 131 connected in parallel is because the second heating unit 131 is fused, so the resistance value of the first heating unit R1 is 910Ω, and the total heating is calculated according to the formula The power is 53.18W.

It can be known that when the controllable circuit protector 10 with multiple power supply voltages is suitable for different power supply 20 voltage environments, the total heating power can be maintained close to each other without violent changes with the power supply 20 voltage, making the The fusing time of the first low-temperature metal fuse 11 or the second low-temperature metal fuse 12 can be stabilized, and the fusing is instantaneous to protect the load 30.

For another example, please refer to FIG. 4, FIG. 5 and FIG. 6, the number of the second heating units 131 to 13n is two, the resistance value of the first heating unit R1 is 1050Ω, and the second heating The second heating element R131 in the unit 131 is 1000Ω, and the second heating unit R132 in the other second heating unit 132 is 480Ω.

As shown in FIG. 4, when the controllable circuit protector 10 of various power supply voltages is suitable for an environment where the voltage value of the power supply 20 is 110V, and when the load 30 abnormally makes the switch SW1 conductive, the second heating The fuses 141 and 142 in the units 131 and 132 will not be blown, so the equivalent resistance and the total heating power are calculated according to the following two formulas:

;

;

The equivalent resistance of the first heating unit R1 and the second heating units 131 and 132 in parallel is 247.78Ω, and the total heating power is calculated according to the formula to be 48.83W.

As shown in FIG. 5, when the controllable circuit protector 10 of various power supply voltages is suitable for an environment where the voltage value of the power supply 20 is 165V, and when the load 30 abnormally turns on the switch SW1, the other second The fuse 142 in the heating unit 132 is blown, so the equivalent resistance and the total heating power are calculated according to the following two formulas:

The equivalent resistance of the first heating unit R1 and the second heating unit 131 connected in parallel is because the other second heating unit 132 has been fused, so the first heating unit R1 and the second heating unit 131 are connected in parallel. The effective resistance is 512.19Ω, and the total heating power calculated according to the formula is 53.15W.

As shown in FIG. 6, when the controllable circuit protector 10 of various power supply voltages is suitable for an environment where the voltage value of the power supply 20 is 220V, and when the load 30 abnormally causes the switch SW1 to be turned on, the second The fuses 141 and 142 in the heating units 131 and 132 are all blown, so the equivalent resistance and the total heating power are calculated according to the following two formulas:

The equivalent resistance of the first heating unit R1 and the second heating unit 131 in parallel is fused because the second heating units 131 and 132 are fused, so the resistance value of the first heating unit R1 is 1050Ω, and according to the formula The calculated total heating power is 46.09W.

Therefore, it can be known that when the controllable circuit protectors 10 with multiple power supply voltages are suitable for different power supply 20 voltage environments, the total heating power does not change drastically.

Please refer to FIG. 7 and FIG. 8, when the number of the second heating units 131 to 13n is five, they can be respectively applied to six different power supply 20 input voltages. Under different input voltages, the melting time of the first low temperature metal fuse 11 or the second low temperature metal fuse 12 can be stably maintained at about 5 to 7 seconds, and according to FIG. 3, there are six different Under the input voltage, the total heating power is stably maintained at about 45 ~ 54W, so the controllable circuit protector of the present invention for a variety of power supply voltages can indeed be applied to a variety of different power supply 20 input voltages, and all can be used at this load. When 30 is abnormal, the first low-temperature metal fuse 11 or the second low-temperature metal fuse 12 is immediately blown to protect the load 30.

The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention has been disclosed as above with the preferred embodiments, they are not intended to limit the present invention, and any technology familiar with the profession Personnel, without departing from the scope of the technical solution of the present invention, can use the disclosed technical content to make a few changes or modify the equivalent embodiment of equivalent changes, but as long as it does not depart from the technical solution of the present invention, according to the present invention Any simple modifications, equivalent changes, and modifications made to the above embodiments by the technical essence of the invention still fall within the scope of the technical solution of the present invention.

10‧‧‧Controllable circuit protector
11‧‧‧The first low temperature metal fuse
12‧‧‧Second Low Temperature Metal Fuse
131 ~ 13n‧‧‧Second heating unit
141 ~ 14n‧‧‧Fuse
20‧‧‧ Power
30‧‧‧Load
40‧‧‧ fuse device
41‧‧‧First temperature fuse
42‧‧‧Second Temperature Fuse
50‧‧‧ Power
60‧‧‧Load

FIG. 1 is a schematic diagram of a device according to a preferred embodiment of the present invention. FIG. 2 and FIG. 3 are schematic diagrams illustrating the use of a preferred embodiment of the present invention. FIG. 4, FIG. 5 and FIG. 6 are schematic diagrams illustrating another exemplary use of the preferred embodiment of the present invention. FIG. 7 is a graph showing a relationship between an input voltage and a fuse breaking time in a preferred embodiment of the present invention. FIG. 8 is a graph showing a relationship between an input voltage and a resistance heating power according to a preferred embodiment of the present invention. Figure 9 is a schematic circuit diagram of a general fuse device.

10‧‧‧Controllable circuit protector

11‧‧‧The first low temperature metal fuse

12‧‧‧Second Low Temperature Metal Fuse

131 ~ 13n‧‧‧Second heating unit

141 ~ 14n‧‧‧Fuse

20‧‧‧ Power

30‧‧‧Load

Claims (9)

A controllable circuit protector suitable for various power supply voltages includes: a first low temperature metal fuse; a second low temperature metal fuse connected in series with the first low temperature metal fuse; wherein the first low temperature metal fuse The free end of the fuse forms an input end, and the free end of the second low temperature metal fuse forms an output end; a first heating unit, one end of which is electrically connected to the first low temperature metal fuse and the second The low temperature metal fuse is connected in series, and the free end of the first heating unit forms a control end; at least one second heating unit is connected in parallel with the first heating unit. The controllable circuit protector applicable to various power supply voltages according to claim 1, wherein the first low-temperature metal fuse and the second low-temperature metal fuse are alloy metal fuses. The controllable circuit protector according to claim 1, which is applicable to various power supply voltages, wherein the first heating unit is a heating resistor or a heater. The controllable circuit protector according to any one of claims 1 to 3, wherein each of the at least one second heating unit includes: a second heating element; and a fuse, and It is connected in series with the second heating element. The controllable circuit protector according to claim 4, which is applicable to various power supply voltages, wherein the second heating element is a heating resistor or a heater. The controllable circuit protector according to any one of claims 1 to 3, which is applicable to various power supply voltages, wherein the cut-off capacity of the fuse of each of the at least one second heating unit is smaller than that of the first low-temperature metal fuse or The second low-temperature metal fuse has a current interrupting capacity. The controllable circuit protector applicable to various power supply voltages as described in claim 4, wherein the cut-off capacity of the fuse of each of the at least one second heating unit is smaller than the first low-temperature metal fuse or the second low-temperature metal fuse Wire cut-off capacity. The controllable circuit protector according to any one of claims 1 to 3, which is applicable to multiple power supply voltages, wherein the cut-off capacities of the fuses of the at least one second heating unit are different from each other. As described in claim 4, the controllable circuit protector applicable to multiple power supply voltages, wherein the cut-off capacities of the fuses of the at least one second heating unit are different from each other.