JPS6358902A - Demagnetizing element - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention uses a positive temperature coefficient thermistor connected in series to a degaussing coil used in a cathode ray tube of a color television receiver to reduce residual current. This invention relates to a demagnetizing element using a heater element.

BACKGROUND OF THE INVENTION Conventionally, this type of demagnetizing element has had a structure as shown in FIG. 4 (Japanese Utility Model Publication No. 166474/1983). In FIG. 4, reference numeral 1 denotes a positive characteristic thermistor for demagnetization having electric parts 2 on both sides, and its Curie temperature is 50°C. Reference numeral 3 designates another positive temperature coefficient thermistor for the heater, which is also provided with an electrode 4, and its Curie temperature is 120°C. Reference numeral 5 denotes a common terminal plate such as a silver-plated brass plate, which is in common contact with one electrode of each of the positive temperature coefficient thermistors 1 and 3. Reference numerals 6 and 7 denote spring terminals made of stainless steel or the like, which press and hold the two PTC thermistors 1 and 3 from the outside, and are in contact with the other electrode of each PTC thermistor 1 and 3. 8 is a bottom plate made of phenolic resin, etc., with spring terminals, etc.

A and a common terminal board 5 are held. Reference numeral 9 denotes a case made of 7-enol resin or the like, which houses the positive temperature coefficient thermistors 1, 3, and the like.

FIG. 5 is a circuit diagram of the use of such a degaussing element. A positive coefficient thermistor 1 for degaussing is connected in series with a degaussing coil 1o wound around a cathode ray tube of a color television receiver. As mentioned above, 3 is a positive temperature coefficient thermistor for the heater, which is thermally coupled to the above described positive coefficient thermistor 1 for demagnetization.

A positive temperature coefficient thermistor is a semiconductor ceramic whose main component is barium titanate, and its resistance is low up to a certain temperature (Curie temperature), and its resistance increases rapidly when the temperature rises above that point.

When a voltage is applied to this positive temperature coefficient thermistor, a large current flows because the resistance is initially low, and at the same time, the positive temperature coefficient thermistor itself generates heat and its temperature rises. When the temperature reaches the Curie temperature, the resistance value increases, the current decreases, the amount of heat generated decreases, and the device stabilizes in a thermal equilibrium state. Therefore, when an alternating current voltage is applied, a large current initially flows through the degaussing coil 10, and a large alternating magnetic field is generated.

Thereafter, as the current decreases, the generated magnetic field also decreases, so demagnetization is performed. At this time, a voltage is also applied to the PTC thermistor 3 for the heater, and the heat is transferred to the PTC thermistor 1 for demagnetization, so the thermal equilibrium temperature of the PTC thermistor 1 for demagnetization rises, and its resistance value increases. Therefore, the magnetic field in the stable state becomes smaller.

The problem that the invention seeks to solve Such a conventional configuration has the following drawbacks.

In other words, in order to make the stable current of the PTC thermistor for demagnetization smaller, the thermal coupling with the PTC thermistor for the heater is sufficient, and the heat of the PTC thermistor for the heater is transferred to the PTC thermistor for demagnetization. It would be nice if we could give them enough information, but in the conventional configuration, they are crimped together with spring terminals, so both positive temperature coefficient thermistors may be warped, or
If there are irregularities, a space will be created between the two and the thermal coupling between them will be insufficient, making it impossible for the positive temperature coefficient thermistor for heaters to exhibit its full effect, and the current flowing to the positive temperature coefficient thermistor for demagnetization to be sufficiently small. It didn't happen. Also, for that purpose,
Conventional configurations require polishing both sides of a positive temperature coefficient thermistor, making it expensive. Furthermore, since the spring terminals are crimped, the strength of the bottom plate for holding the spring terminals is required, which necessitates increasing its thickness, which is also expensive. Additionally, there was a risk that the positive temperature coefficient thermistor would move due to vibration, resulting in poor contact.

The present invention solves these problems, and aims to provide a highly reliable demagnetizing element that has sufficient thermal coupling between both positive temperature coefficient thermistors, has a small stable current, is resistant to vibrations and shocks, and is highly reliable. It is something.

Means for Solving the Problem In order to solve this problem, the present invention provides a first positive temperature coefficient thermistor for demagnetization, a second positive coefficient thermistor for a heater having a higher Curie temperature than the first positive coefficient thermistor, and three One common lead terminal is connected between the two positive temperature coefficient thermistors which are placed so that one electrode surface faces each other, and one common lead terminal is connected to the other electrode. It has lead terminals fixed with solder.

Effect With this configuration, when the degaussing coil is connected in series to the first positive coefficient thermistor for degaussing and an alternating current voltage is applied, a large current initially flows through the degaussing coil, as shown in FIG.
A large alternating magnetic field is generated.

Thereafter, as the current decreases, the generated magnetic field also decreases, so demagnetization is performed. At this time, the voltage is applied to the second PTC thermistor for the heater at the same time, and its Curie temperature is higher than that of the first PTC thermistor for demagnetization, so the stable state temperature is high, and both PTC thermistors are thermally conductive. Because it is fixed with high-rate solder, the heat from the second PTC thermistor is efficiently transferred to the first PTC thermistor, which increases the thermal equilibrium temperature of the first PTC thermistor and increases its resistance value. Therefore, the steady-state current is reduced, and the unnecessary steady-state magnetic field is reduced.

Embodiment FIG. 1 is a front sectional view of a degaussing element according to an embodiment of the present invention. In FIG. 1, reference numeral 11 is a first positive temperature coefficient thermistor having a Curie temperature of 50° C., which is provided with caps 12 on both sides. 13 is a second positive temperature coefficient thermistor having a Curie temperature of 120'C and having electrodes 14 on both sides.

Reference numerals 16, 16, and 17 are lead terminals made of copper or the like, one of which is fixed with solder 18 to the opposing electrode surfaces of the two positive temperature coefficient thermistors 11 and 13, and the other two are connected to other terminals. It is similarly fixed to each electrode surface with solder 18.

In the demagnetizing element according to the present invention, the electrode surfaces of the first positive temperature coefficient thermistor for demagnetization and the second positive coefficient thermistor for the heater are fixed with solder, and the lead terminals are also fixed with solder. Even if the characteristic thermistor is warped or uneven, the solder with good thermal conductivity will provide sufficient thermal coupling between the two, increasing the thermal equilibrium temperature of the positive characteristic thermistor for demagnetization, and reducing the stable current. Furthermore, since the lead terminals are fixed to the electrodes with solder, there is no risk of poor contact, and reliability is high.

FIG. 2 is another embodiment of the present invention. In FIG.
11 has electrodes 12 on both sides and has a Curie temperature of 50
℃ first positive characteristic thermistor. 13 is a second electrode having a Curie temperature of 120°C and having electrodes 14 on both sides.
It is a positive characteristic thermistor. Reference numerals 15, 16 and 17 are lead terminals made of copper or the like, one of which is fixed with solder 18 to the opposing electrode surfaces of the two positive temperature coefficient thermistors 11 and 13, and the other two are It is similarly fixed to each electrode surface with solder 18. Reference numeral 19 is an insulating resin such as epoxy or silicone, which covers the two positive temperature coefficient thermistors 11 and 13.

With this configuration, the area around the degaussing element is insulated, eliminating the risk of short circuiting even if other components come into contact with each other on the circuit board.

FIG. 3 shows yet another embodiment. 11 in Figure 3
The Curie temperature is 50 when the electrode 12 is provided on both electrode surfaces.
℃ first positive characteristic server star. 13 is a second electrode having a Curie temperature of 120°C and having electrodes 14 on both sides.
It is a positive characteristic thermistor. Reference numerals 15, 16, and 17 are lead terminals made of copper or the like, one of which is fixed with solder 18 to the opposing electrode surfaces of the two positive temperature coefficient thermistors 11 and 13, and the other two are soldered separately. Similarly, it is fixed to each electrode surface with solder 18. 20 is a bottom plate made of phenolic resin, etc., with lead terminals 15, 16, 17
It penetrates and is fixed. Reference numeral 21 denotes a case made of phenol resin or the like, which houses positive temperature coefficient thermistors 11 and 13.

With this configuration, since there is a space between the positive temperature coefficient thermistor and the case, the temperature outside the case is lower, and since it is insulated, when used on a circuit board, The effect of heat on other parts is eliminated, making it easier to use. In addition, since the lead terminals are fixed and held in the PTC server with solder, they do not require strength to hold them like spring terminals do, so the thickness of the bottom plate can be made thinner. Therefore, it is possible to provide an inexpensive demagnetizing element.

Effects of the Invention As described above, according to the present invention, even if a PTC thermistor has warpage or unevenness, it is possible to improve thermal coupling without polishing it, and it is possible to provide a demagnetizing element that is inexpensive and has a small stable current. . In addition, since the lead terminals are fixed with solder, there is no risk of poor contact, and when stored in the case,
Since the strength of the bottom plate is unnecessary, a highly reliable demagnetizing element can be provided at low cost.

[Brief explanation of the drawing]

1, 2, and 3 are front sectional views showing demagnetizing elements according to embodiments of the present invention, FIG. 4 is a front sectional view showing conventional demagnetizing elements, and FIG. 5 is a front sectional view showing these demagnetizing elements. FIG. 2 is a circuit diagram showing a circuit when used. 11...Positive characteristic thermistor for demagnetization, 12...
...Electrode, 13...Positive characteristic thermistor for heater, 14...2 poles, 15,16.17...
...Lead terminal, 18...Solder, 19...
...Resin, 20...Bottom plate, 21...
·Case.

Claims (3)

[Claims] (1) It has a first positive temperature coefficient thermistor for demagnetization, a second positive coefficient thermistor for the heater with a higher Curie temperature, and three lead terminals, each with one electrode surface facing opposite to the other. A degaussing element has one common lead terminal fixed between the two positive temperature coefficient thermistors and another lead terminal fixed to the other electrode by solder. (2) A demagnetizing element according to claim 1, wherein the two positive temperature coefficient thermistors are covered with an insulating resin. (3) Two positive temperature coefficient thermistors are housed in an insulating case, and the ends of the three lead terminals are exposed outside the insulating case and are fixed to the wall of the insulating case. The demagnetizing element according to item 1.