JP2002231510A - Current-control resistor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a current-control resistor element capable of making a current vary in intensity with time from heavy to small level and also making a resistance value vary in optional form irrespective of voltage. SOLUTION: A synthetic resistor 1 formed of 90 to 10 vol.% of a tellurium material and 10 to 90 vol.% of a carbon material is disposed inside a cylindrical holder 2 of a ceramic material, and external connection terminals 3 of a metal material connected to ends of the synthetic resistor 1 are fixed to ends of the holder 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current control resistance element used for controlling a heating element such as an electric furnace.

[0002]

2. Description of the Related Art Conventionally, a heating element for generating a temperature of 0.01 ohm or less has
When a voltage of ~ 400 volts is applied, a power regulator using a semiconductor is often destroyed due to an initial excessive current, and a heating element is heated using a transformer at a voltage of 100 volts or less. In many cases, a specified voltage is applied after the resistance value of the increases.

[0003] In addition, the voltage adjustment method starting from 0 volts by the Slidac has a drawback that it cannot be accommodated in an electric furnace or the like due to large power, and the automatic adjustment device for adjusting the heat generation temperature becomes large. Therefore, there is a disadvantage that the adjustment is always performed manually.

Although a resistor can be used to prevent an initial excess current, the power used by the heating element is 10 kilowatts or more, and a small electric furnace has a large resistance, and the heat generated by the resistor is radiated. In an electric furnace where the heating temperature of the heating element is 1500 ° C. or higher, the resistor is melted because it has many nichrome wires when put together inside the electric furnace, so it is not normally used. .

Although a semiconductor rectifying element for a large current can be used for current limiting, there is a disadvantage that the internal resistance of the semiconductor does not change to a gradually lower resistance, and a heat destruction occurs due to an increase in self-temperature, resulting in heat dissipation. The disadvantage is that the costs associated with the plate and cooling are high.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned disadvantages of the prior art, which prevents a semiconductor power regulator from being destroyed due to an initial excessive current of a heating element having a low resistance value, and directly generates a heating element without using a transformer. It is an object of the present invention to provide a current control resistance element that can control the current to a desired voltage.

[0007]

According to a first aspect of the present invention, there is provided a current control resistance element having a volume ratio of 90% inside a cylindrical holder made of a ceramic material.
% To 10% tellurium material and 10% to 9% by volume
Arrange a synthetic resistance element made of 0% carbon material,
An external connection terminal made of a metal material connected to both ends of the synthetic resistance element is fixed to both ends of the holder, and the current control resistance element according to claim 2,
A synthetic resistance element made of a tellurium material having a weight ratio of 80% to 20% and a metal material having a weight ratio of 20% to 80% is disposed inside a cylindrical holder made of a ceramic material,
An external connection terminal made of a metal material connected to both ends of the combined resistance element is fixed to both ends of the holder.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show an embodiment of a current control resistor according to the present invention. FIG. 1 is a perspective view of a composite resistor, FIG. 2 is a plan view of the current control resistor, and FIG. FIG. 4 is an electric circuit diagram, FIG. 4 is a diagram for explaining electric characteristics of the current control resistance element, and FIG. 5 is an electric circuit diagram showing an application example of the current control resistance element.

In FIG. 1, a composite resistance element 1 constituting a current control resistance element according to the present invention is obtained by mixing powder of a tellurium material and a carbon material to have an arbitrary shape and an arbitrary high resistance value or low resistance value. 90% to 10% by volume to obtain
Is mixed with 10% to 90% by volume of a carbon material powder, and the mixed powder is press-compressed into an arbitrary shape to be formed. In the embodiment of FIG. 1, the combined resistance element 1 is formed in a cylindrical shape, but may be formed in any shape such as a prismatic shape, an elliptic cylindrical shape, and the like.

In another embodiment, a powder of an arbitrary metal material is mixed with a powder of tellurium material to reduce the resistance, the large current, and the change time of the resistance value. Powder such as copper, nickel, and aluminum is used as the metal material. When a metal material is mixed, a powder of tellurium material having a weight ratio of 80% to 20% and a metal powder having a weight ratio of 20% to 80% are obtained in order to obtain an arbitrary resistance value and a change time of the resistance value. The bodies are mixed and press-compressed into any shape to form.

FIG. 2 shows a current control resistance element A. The composite resistance element 1 is disposed inside a holder 2 made of a cylindrical ceramic material.
A is connected to an external connection terminal 3 made of a metal material, and the external connection terminal 3 is fixed to both ends 2 </ b> A of the holder 2. The ceramic material of the holder 2 is an electrically insulating material and uses an alumina silicon oxide system that can withstand high temperatures. The external connection terminal 3 is provided with a connection screw terminal 3A for connecting to an electric circuit.

As shown in FIG. 3, when a heating element (resistance) R and an AC power supply are connected to the connection screw terminals 3A at both ends of the current control resistance element A, the current control resistance element A
, The current flowing through the circuit causes the internal resistance of the current control resistance element A to gradually decrease in resistance due to self-heating. Therefore, a gradually increasing current flows through the heating element R. In this case, the current control resistance element A generates heat in proportion to the flowing current, but since the resistance value of the tellurium material itself decreases, the resistance becomes reddish like other linear resistors. There is no. In addition, since the tellurium material itself generates heat quickly, it does not reach a high temperature unlike other linear resistors even under the same power condition.

FIG. 5 shows a current control resistor element A according to the present invention.
An application example in which a phase circuit is connected between the SCR semiconductor power regulator 4 and three heating elements R is shown. Although the resistance value of the voltage adjusting resistor 5 connected to the SCR semiconductor power regulator 4 is adjusted to adjust the summer time applied to the heating element R, the adjustment of the voltage adjusting resistor 5 is forgotten and the heating element R is forgotten. Even if a high voltage is applied, since the current control resistance element A is connected to the circuit,
The destruction of the SCR semiconductor power regulator 4 can be prevented.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made. For example, in the above embodiment, the current control resistance element and the heating element are connected to an AC circuit, but may be connected to a DC circuit.

[0015]

As is apparent from the above description, according to the present invention, a small current to a large current, a change time of a resistance value and the like can be varied in any shape regardless of a voltage, and a heat radiating device is required. Instead, it can be used up to its own temperature of about 450 ° C. Further, it is possible to prevent the semiconductor power regulator from being destroyed due to the initial excessive current of the heating element having a low resistance value, and to directly control the heating element to a desired voltage without using a transformer.

[Brief description of the drawings]

FIGS. 1 to 5 show one embodiment of a current control resistance element according to the present invention.
FIG. 1 shows an embodiment, and FIG. 1 is a perspective view of a combined resistance element.

FIG. 2 is a plan view of a current control resistance element.

FIG. 3 is an electric circuit diagram of a current control resistance element.

FIG. 4 is a diagram for explaining electrical characteristics of a current control resistance element.

FIG. 5 is an electric circuit diagram showing an application example of the current control resistance element.

[Explanation of symbols]

 1: Synthetic resistance element 2: Holder 3: External connection terminal

Claims (2)

[Claims] 1. A synthetic resistance element made of a tellurium material having a volume ratio of 90% to 10% and a carbon material having a volume ratio of 10% to 90% is disposed inside a cylindrical holder made of a ceramic material. An external connection terminal made of a metal material connected to both ends of the combined resistance element is fixed to both ends of the holder. 2. A synthetic resistance element made of a tellurium material having a weight ratio of 80% to 20% and a metal material having a weight ratio of 20% to 80% is disposed inside a cylindrical holder made of a ceramic material. An external connection terminal made of a metal material connected to both ends of the combined resistance element is fixed to both ends of the holder.