JPH0935908A - Positive temperature coefficient thermistor device and demagnetizing circuit using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat dissipation capability and shorten recovery time until a current can be again applied, by accommodating a positive temperature coefficient thermistor element in a case, in the state that the plane part and the spring part of a pair of terminals are made to abut against be electrode of the thermistor element, and extruding the other ends of a pair of the terminals from the case. SOLUTION: In a positive temperature coefficient thermistor device 20, a positive temperature coefficient thermistor element 21 is accomodated in a case 24, in the state that both main surfaces of the element, i.e., electrodes 25, 25 are made to abut against the plane part 22a of a flat terminal 22 and the spring part 23a of a spring terminal 23. The thermistor device 20 is so assembled that the lead terminal part 22b of the flat terminal 22 and the lead terminal part 23b of the spring terminal 23 are extruded from the case 24. A planar radiation board is arranged between the positive temperature coefficient thermistor element 2 and the spring terminal 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive temperature coefficient thermistor device used for degaussing a cathode ray tube such as a color television or a color monitor, and a degaussing circuit using the thermistor device.

[0002]

2. Description of the Related Art Conventionally, there is a positive temperature coefficient thermistor device shown in FIG. The positive temperature coefficient thermistor device 10 of the first conventional example includes a positive temperature coefficient thermistor element 1, a pair of terminals 2 and 2, and a case 4.

In the PTC thermistor element 1, electrodes 1a, 1a are formed on both main surfaces of a plate-shaped PTC thermistor element body. A spring portion 2a is formed at one end of the pair of terminals 2 and 2, and narrow lead terminal portions 2b and 2b are formed at the other end. The case 4 is composed of a resin-molded case body 4a having an open top surface and a lid body 4b, and an upper opening of the case body 4a is closed by a lid body 4b.

In the positive temperature coefficient thermistor device 10, the positive temperature coefficient thermistor element 1 is housed in a case 4 with its main surfaces, that is, the electrodes 1a, 1a, brought into contact with the spring portions 2a, 2a of the pair of terminals 2, 2. The other ends of the pair of terminals 2 and 2 are extended to the outside of the case 4 and assembled.

Further, another PTC thermistor device is conventionally shown in FIG. The PTC thermistor device 11 of the second conventional example is composed of a PTC thermistor element 1, a pair of terminals 6 and 6, and an insulating coating 7. This positive temperature coefficient thermistor device 11 includes a pair of terminals 6 and 6 formed of lead wires or the like on the electrodes 1a of the positive temperature coefficient thermistor element 1.
One end of the positive temperature coefficient thermistor element 1 is soldered with a solder 8 and the positive temperature coefficient thermistor element 1 is covered with an insulating coating 7 such as an epoxy resin.

[0006] Such a positive temperature coefficient thermistor device 10, 1
As an application example of No. 1, there is a degaussing circuit shown in FIG. This degaussing circuit is configured by connecting a positive temperature coefficient thermistor device 10 or 11, a degaussing coil 13, and a switch 14 to a power supply 15 in series. In this degaussing circuit, switch 1
When 4 is turned on and power is supplied, an initial current flows through the positive temperature coefficient thermistor device 10 (11) and the degaussing coil 13 at the start of power supply. Then, while the current flowing through the degaussing circuit gradually decreases due to the current-time characteristic of the positive temperature coefficient thermistor device 10 (11), heat dissipation and heat generation of the positive temperature coefficient thermistor device 10 (11) reach a balanced state and become a stable current. .

[0007]

However, the above-mentioned conventional positive temperature coefficient thermistor device and the degaussing circuit using the same have the following problems. That is, since the positive temperature coefficient thermistor device 10 of the first conventional example and the positive temperature coefficient thermistor device 11 of the second conventional example do not have a structure that exhibits a heat dissipation effect, the resistance of the positive temperature coefficient thermistor element 1 is cut off after the power supply 15 of the degaussing circuit is cut off. It took time for the value to become sufficiently small. Therefore, for example, even if the positive temperature coefficient thermistor devices 10 and 11 are re-energized before they are restored, the inrush current flowing in the degaussing circuit becomes small, and the degaussing effect cannot be sufficiently exhibited.

Therefore, an object of the present invention is to solve the above-mentioned problems, and a positive temperature coefficient thermistor device having good heat dissipation of the positive temperature coefficient thermistor device and a short recovery time before re-energization, and the same. The purpose is to provide a degaussing circuit using.

[0009]

In order to achieve the above object, a PTC thermistor device of the present invention comprises a PTC thermistor element, a pair of terminals, and a case,
The positive temperature coefficient thermistor element is an electrode is formed on both main surfaces of a plate-shaped positive temperature coefficient thermistor body, the pair of terminals comprises a flat terminal having a flat plate portion at one end and a spring terminal having a spring portion, The positive temperature coefficient thermistor element electrodes are accommodated in the case in which the flat plate portions and the spring portions of the pair of terminals are in contact with each other, and the other ends of the pair of terminals extend from the case. Is characterized by.

Further, the flat plate portion of the flat terminal is in contact with the inner wall of the case. Furthermore, the above-mentioned PTC thermistor device is characterized in that a plate-shaped heat dissipation plate is arranged between the PTC thermistor element and the spring terminal.

Furthermore, the positive temperature coefficient thermistor device, the degaussing coil, and the energization interruption element are connected in series to the power source, and are used in a circuit in which the energization interruption element interrupts energization after a lapse of a predetermined time from the start of energization. To do.

In the degaussing circuit using the PTC thermistor device according to the present invention, the PTC thermistor device, the degaussing coil, and the energization interruption element are connected in series to the power source.
It is characterized in that energization is interrupted by the energization interrupting element after a lapse of a predetermined time from the start of energization.

As a result, the flat portion of the flat terminal is brought into contact with one main surface of the PTC thermistor element, and is further brought into contact with the case, and the heat from the PTC thermistor element passes through the flat terminal and the case. Is dissipated. Furthermore, the heat dissipation plate is in contact with the other main surface of the positive temperature coefficient thermistor which is in contact with the spring terminal, and the heat from the positive temperature coefficient thermistor element is radiated through the heat dissipation plate.

[0014]

DETAILED DESCRIPTION OF THE INVENTION One embodiment according to the present invention will be described in detail below with reference to FIGS. The PTC thermistor device 20 includes a PTC thermistor element 21.
And a flat terminal 22 and a spring terminal 23, which are a pair of terminals,
And a case 24.

The positive temperature coefficient thermistor element 21 is a plate-shaped positive temperature coefficient thermistor element 21a having electrodes 25 formed on both main surfaces thereof. This electrode 25 maintains an ohmic contact with the PTC thermistor body 21a, for example, a nickel layer formed by electroless plating on the lower layer 25a and an outer layer 25b.
And a silver layer containing silver as a main component by baking. And to prevent migration by silver,
The lower layer 25a is preferably formed on both main surfaces of the PTC thermistor element body, and the outermost layer 25b is preferably formed with a gap G from the end of the lower layer 25a.

The flat terminal 22 is made of a metal such as nickel silver having a good thermal conductivity, has a flat plate portion 22a larger than the diameter of the positive temperature coefficient thermistor element 21 at one end, and has a narrower lead terminal than the flat plate portion 22a at the other end. It has a portion 22b. The spring terminal 23 is made of a metal having a good spring property such as phosphor bronze, has a spring portion 23a protruding from a flat portion larger than the diameter of the positive temperature coefficient thermistor element 21 at one end, and has a width narrower than the flat portion at the other end. It has a lead terminal portion 23b.

The case 24 is composed of a resin-molded case body 24a having an open top surface and a lid 24b for closing the opening of the case body 24a. The bottom of the case body 24a has holes (not shown) into which the lead terminals 22b and 23b of the flat terminal 22 and the spring terminal 23 can be inserted.

In the PTC thermistor device 20, the PTC thermistor element 21 has a flat plate portion 22a of the flat terminal 22 and a spring portion 23a of the spring terminal 23 on both main surfaces thereof, that is, the electrodes 2.
The lead terminals 22b of the flat terminals 22 and the lead terminals 23b of the spring terminals 23 are extended to the outside of the case 24 and assembled. Then, the flat plate portion 22a of the flat terminal 22 is brought into contact with the inner wall 24c of the case 24. Therefore, one main surface of the positive temperature coefficient thermistor element 21 is brought into contact with the inner wall 24a of the case 24 via the flat plate portion 22a.

Next, another embodiment according to the present invention will be described with reference to FIG.
This will be described in detail with reference to FIG. However, the same parts as those in the above-described one embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The PTC thermistor device 30 includes a PTC thermistor element 21, a pair of terminals, a flat terminal 22 and a spring terminal 33, a heat radiating plate 36, and a case 24.

The spring terminal 33 is made of a spring metal such as phosphor bronze, has a spring portion 33a bent at one end to press the PTC thermistor element 21, and has a narrow lead terminal at the other end. It has a portion 33b.

The heat radiating plate 36 is made of a metal having good heat conduction such as a copper alloy and has a flat plate shape larger than the diameter of the positive temperature coefficient thermistor element 21.

In the PTC thermistor device 30, the PTC thermistor element 21 contacts the flat plate portion 22a of the flat terminal 22 and the heat radiating plate 36 with the electrodes 25, 25 on both main surfaces thereof in contact with the spring of the spring terminal 33. The portion 33 a is pressed through the heat dissipation plate 36 and is housed in the case 24. Then, the lead terminal portion 22b of the flat terminal 22 and the spring terminal 33
The lead terminal portion 33b is extended to the outside of the case 24 and assembled. Further, the flat plate portion 22 of the flat terminal 22
The a is in contact with the inner wall 24c of the case 24. Therefore, one main surface of the positive temperature coefficient thermistor element 21 is brought into contact with the inner wall 24a of the case 24 via the flat plate portion 22a.

Next, the degaussing circuit according to the present invention will be described in detail with reference to FIG. In this degaussing circuit, a positive temperature coefficient thermistor device 40, a degaussing coil 42, a switch 43, and an energization interruption element 44 are connected in series to a power supply 45.

The degaussing coil 42 is a coil for removing the magnetic field magnetized in the shadow mask such as a color cathode ray tube. The energization interrupting element 44 interrupts energization by a relay, a bimetal or the like after a lapse of a predetermined time, for example, 5 to 30 seconds from the start of energization.

In this degaussing circuit, when the switch 43 is turned on and the degaussing circuit is energized, an initial current flows through the positive temperature coefficient thermistor device 40 and the degaussing coil 42 at the start of energization. Then, while the current flowing through the degaussing circuit gradually decreases due to the current-time characteristic of the positive temperature coefficient thermistor device 40, the current cut-off element 43 cuts off the energization of the degaussing circuit after 5 to 30 seconds. After the interruption, the heat of the positive temperature coefficient thermistor device 40 is dissipated, and for example, after about 2 minutes, the heat is restored. As the PTC thermistor device 40 shown in this degaussing circuit, the PTC thermistor device 20 and the PTC thermistor device 30 of the above-described embodiment are used.

(Evaluation Test) An evaluation example comparing the heat radiation effect between the above-described embodiment and the conventional example will be described below. A PTC thermistor device 20 according to one embodiment was prepared by preparing a PTC thermistor element having a diameter of 14 mm, a thickness of 2.3 mm, a room temperature resistance of 5Ω, and a Curie temperature of 60 ° C.
Then, the degaussing circuit shown in FIG.
5 AC100Vrms, 60Hz, power cutoff element 44
After applying for 6 seconds, the power supply 45 was cut off and the time for the PTC thermistor device 20 to recover was measured. Table 1 shows the results. The recovery time at this time is a resistance value that is twice the resistance value of the positive temperature coefficient thermistor element at 25 ° C., that is, the time when the resistance value of the positive temperature coefficient thermistor element returns to 10Ω.

As Comparative Example 1, the same positive temperature coefficient thermistor element as described above is used, and the positive temperature coefficient thermistor device 1 of the first conventional example is used.
0 was created. Further, as Comparative Example 2, the same positive temperature coefficient thermistor element as described above was used, and a positive temperature coefficient thermistor device 11 of the second conventional example was produced. Then, the recovery times were measured under the same conditions as above, and the results are shown in Table 1.

As can be seen from Table 1, the recovery time of the PTC thermistor device according to the present invention is shorter than that of the conventional example.

[0029]

[Table 1]

As can be seen from the above-mentioned evaluation example, the positive temperature coefficient thermistor devices 30 and 40 according to the present invention radiate heat well from the heat generated positive temperature coefficient thermistor element 21, and as a result, the positive temperature coefficient thermistor devices 30 and 40 are demagnetized. The stable current flowing becomes larger than the stable current flowing through the positive temperature coefficient thermistor devices 10 and 11 of the conventional example. Therefore, the positive temperature coefficient thermistor device according to the present invention having the improved heat dissipation characteristic is suitable for the degaussing circuit using the current cutoff element 44. Also,
By using the positive temperature coefficient thermistor device according to the present invention for the degaussing circuit according to the present embodiment, it is possible to shorten the waiting time when the degaussing circuit is operated intermittently.

[0031]

As described above, in the PTC thermistor device according to the present invention, since the flat plate portion of the flat terminal having good heat conduction is in contact with one main surface of the PTC thermistor element,
Heat from the PTC thermistor element is well dissipated through the flat terminal.

Further, since the flat plate portion of the flat terminal which is in contact with one main surface of the positive temperature coefficient thermistor element is further in contact with the inner wall of the case, heat of the positive temperature coefficient thermistor element is well transferred through the case. Dissipated.

Furthermore, when the heat dissipation plate having good heat conduction is brought into contact with the other main surface of the PTC thermistor element, the heat of the PTC thermistor element is well dissipated through the heat dissipation plate. The effect is obtained.

The positive characteristic thermistor device and the current cutoff element according to the present invention are connected in series to form a degaussing circuit, whereby the stable current flowing through the positive characteristic thermistor device is cut off after a predetermined time elapses, and the positive characteristic When the thermistor device is quickly dissipated and re-energized, an effect is obtained in which a sufficient initial current flows through the PTC thermistor device and the degaussing coil.

[Brief description of drawings]

FIG. 1 is a partial side sectional view showing a PTC thermistor device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a positive temperature coefficient thermistor element, a flat terminal, and a spring terminal used in FIG.

FIG. 3 is a partial side sectional view of a positive temperature coefficient thermistor device according to another embodiment of the present invention.

FIG. 4 is a perspective view of a positive temperature coefficient thermistor element, a flat terminal, a spring terminal, and a heat sink used in FIG.

FIG. 5 is a circuit diagram showing a degaussing circuit according to an embodiment.

FIG. 6 is a partial side sectional view showing a structure of a first conventional example.

FIG. 7 is a partial side sectional view showing a structure of a second conventional example.

FIG. 8 is a circuit diagram showing a conventional degaussing circuit.

[Explanation of symbols]

 20, 30 Positive characteristic thermistor device 21 Positive characteristic thermistor element 22 Flat terminal 22a Flat plate portion 22b Flat terminal lead terminal portion 23 Spring terminal 23a Spring portion 23b Spring terminal lead terminal portion 24 Case 24c Inner wall 25 Electrode 36 Heat sink 40 Positive characteristic Thermistor device 42 Degaussing coil 44 Current interruption element

Claims (5)

[Claims] 1. A positive temperature coefficient thermistor element, a pair of terminals, and a case, wherein the positive temperature coefficient thermistor element has electrodes formed on both main surfaces of a plate-shaped positive temperature coefficient thermistor element, and the pair of terminals. Is composed of a flat terminal having a flat plate portion at one end and a spring terminal having a spring portion, and is housed in the case in a state where the flat plate portion and the spring portion of the pair of terminals are in contact with the electrodes of the positive temperature coefficient thermistor element. A positive temperature coefficient thermistor device, wherein the other ends of the pair of terminals extend from the case. 2. The positive temperature coefficient thermistor device according to claim 1, wherein a flat plate portion of the flat terminal is in contact with an inner wall of the case. 3. The positive temperature coefficient thermistor device according to claim 1 or 2, wherein a flat heat dissipation plate is disposed between the positive temperature coefficient thermistor element and the spring terminal. Characteristic thermistor device. 4. A positive temperature coefficient thermistor device, a degaussing coil, and an energization interruption element are connected in series to a power source, and are used in a degaussing circuit whose energization is interrupted by the energization interruption element after a lapse of a predetermined time from the start of energization. Claims 1, 2
Alternatively, the positive temperature coefficient thermistor device according to item 3. 5. The positive temperature coefficient thermistor device according to claim 1, 2 or 3, a degaussing coil and an energization interruption element are connected in series to a power source, and energization is interrupted by the energization interruption element after a lapse of a predetermined time from the start of energization. A degaussing circuit characterized in that