JP2571990Y2 - Positive characteristic thermistor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application field> The present invention relates to a positive temperature coefficient thermistor device used in a demagnetizing circuit, in which the structure of a power supply terminal is changed by a contact portion that contacts an electrode of the positive temperature coefficient thermistor and an external connection. By providing a structure in which a detour portion is provided between the terminal portion and the terminal portion, and by providing a positioning portion for positioning the contact portion between the terminal and the case, heat conduction from the electrode contact portion to the terminal portion is provided. In addition to suppressing the mechanical contact between the electrode contact part and the detour part, the temperature rise of the terminal part is suppressed, and when used for a degaussing circuit, the residual current is kept low and the degaussing effect is improved. It is made possible.

<Conventional technology> As a positive temperature coefficient thermistor device used in a degaussing circuit, a positive temperature coefficient thermistor for degaussing and a positive temperature coefficient thermistor for heating are sandwiched by a flat plate-shaped terminal made of a metal plate. The best known is a structure in which they are superposed and elastically sandwiched by elastic terminals. Each terminal includes a contact portion that contacts the electrode of the positive temperature coefficient thermistor, and a terminal portion that is continuous with the contact portion, and the terminal portion extends through the case to the outside.

The operation of a degaussing circuit using the above-described PTC thermistor device is well known. The degaussing positive temperature coefficient thermistor is heated by the heating positive temperature coefficient thermistor, and the operating temperature of the degaussing positive temperature coefficient thermistor shifts to a higher temperature than the temperature at which it operates alone. Therefore, the equilibrium point current controlled by the degaussing positive characteristic thermistor and flowing through the degaussing coil is reduced as compared with the case where the degaussing positive characteristic thermistor is used alone, and the demagnetizing effect is improved.

<Problem to be Solved by the Invention> In the degaussing circuit, in order to reduce the equilibrium point current, it is necessary to raise the resistance of the degaussing positive temperature coefficient thermistor to as high a value as possible. In order to increase the resistance value of the degaussing PTC thermistor, it is important to use a heating PTC thermistor having a high resistance value and a high switching temperature TS as well as to reduce the amount of heat radiation. Among the various heat radiation paths, the heat radiation through the terminal that directly contacts the positive temperature coefficient thermistor is greatest. Therefore, in order to reduce the amount of heat radiation, the structure of the terminal is extremely important.

The terminal is a part supported by the case, led out to the outside, and connected to an external circuit. Therefore, it is necessary to suppress the temperature of the terminal, particularly the terminal portion serving as the external lead-out portion, to be as low as possible in order to reduce the adverse thermal effect on the case and the external circuit.

Reducing the amount of heat radiation from the terminal and keeping the temperature of the terminal low are mutually exclusive, and it is not always easy to take a terminal structure that satisfies both at the same time.

Attempts to simultaneously solve the above-described problem of the decrease in the amount of heat radiation and the rise in the terminal temperature are described in, for example, JP-A-1-208803,
It is known in Japanese Patent Application Laid-Open Nos. 1-220403 and 1-130502.

However, the invention described in Japanese Patent Application Laid-Open No. 1-220403 has a structure in which a plurality of independent round holes are provided at intervals with respect to a terminal to form a heat transfer constricted portion, and a sufficient heat radiation reduction and The terminal temperature rise suppression effect cannot be obtained.

The device disclosed in Japanese Patent Application Laid-Open No. 1-208803 is different from Japanese Patent Application Laid-Open No. 1-220403 in that an elongated slit is provided, and an excellent effect of reducing heat radiation and suppressing a rise in terminal temperature is obtained. Not enough.

The device disclosed in Japanese Utility Model Laid-Open No. 1-130502 has a structure in which the thermal coupling plate and the terminal are separated and connected by a thermal resistance member therebetween, so that the structure becomes complicated, assembly becomes difficult, and the number of parts increases. And so on.

Therefore, an object of the present invention is to provide a heat radiation reducing action and a terminal temperature rise suppressing action which are superior to the above-described conventional techniques, and the equilibrium point current when used in a degaussing circuit is small. An object of the present invention is to provide a positive temperature coefficient thermistor device having a small adverse effect.

<Means for Solving the Problems> In order to solve the problems described above, the positive temperature coefficient thermistor device according to the present invention includes a case, two positive temperature coefficient thermistors housed in the case, and electrodes of the positive temperature coefficient thermistor. It has a plurality of conducting terminals and is used for a degaussing circuit.
The two PTC thermistors are superimposed on each other.

One of the terminals is disposed between the two positive temperature coefficient thermistors, and a contact portion that comes into surface contact with the electrodes of the two positive temperature coefficient thermistors, a detour portion, and a terminal led out of the case. And the detour portion is narrower than the contact portion, is disposed at an interval on a side of the contact portion, and directly connects the contact portion and the terminal portion. As described above, one end is connected to one end of the contact portion, and the other end is connected to the terminal.

Preferably, an uneven fitting portion is provided between an inner bottom surface of the case and an edge of the contact portion.

Further, in addition to the above configuration, a projection may be provided on an inner surface of the case facing the inner bottom surface, the protrusion protruding in an arrangement region of the contact portion of the positive temperature coefficient thermistor and the terminal.

<Operation> The terminal has a detour portion, and the detour portion is narrower than the contact portion, and is arranged at an interval beside the contact portion so that the contact portion and the terminal portion are connected in series. In addition, since one end is connected to the contact portion and the other end is connected to the terminal portion, heat conduction from the contact portion to the terminal portion is suppressed by the bypass portion, and the temperature of the terminal portion is kept low. . For this reason, the heat generation temperature of the positive temperature coefficient thermistor increases, and the temperature of the terminal portion decreases, so that the equilibrium point resistance increases and the residual current decreases in the degaussing circuit.

When an uneven fitting portion is provided between the inner bottom surface of the case and the edge of the contact portion of the terminal, the contact portion of the terminal is positioned on the inner bottom surface of the case by the uneven fitting. For this reason, the contact portion does not come into contact with the bypass portion, and the temperature rise of the terminal portion can be more reliably prevented.

Apart from or in addition to the above configuration, by having a projection for receiving the positive temperature coefficient thermistor on the inner bottom surface of the case, the height of the positive temperature coefficient thermistor with respect to the inner bottom surface of the case is positioned, and the positive Vertical misalignment of the characteristic thermistor is prevented. For this reason, it is possible to avoid contact of the PTC thermistor with the detour part due to the vertical displacement of the PTC thermistor.

Similarly, separately from or together with the above configuration,
By providing a projection on the inner bottom surface of the case so as to face the contact portion of the terminal, displacement of the contact portion of the terminal and so-called play are prevented. For this reason,
The contact between the contact portion and the bypass portion can be avoided.

Furthermore, under each of the above configurations, the inner surface of the case facing the inner bottom surface has a protrusion protruding in the area where the contact portion of the positive characteristic thermistor and the terminal is arranged, so that the positive characteristic thermistor and the inner surface of the case can be formed. The contact area between them becomes small, the action of heating the case by the PTC thermistor decreases, and the temperature rise of the case is suppressed. At the same time, the range of movement of the contact portion of the terminal is restricted, and the terminal is positioned at a predetermined position.

<Embodiment> FIG. 1 is a partial cross-sectional view of the PTC thermistor device according to the present invention, FIG. 2 is a cross-sectional view taken along the line A1-A1 in FIG. 1, and FIG. 3 is a partial cross-section taken along the line A2-A2 in FIG. Fig. 4
FIG. 5 is a partial cross-sectional view taken along line B1-B1, FIG. 5 is FIG.
It is a partial sectional view on a line. In the figure, 1 is a case, 2 and 3 are positive temperature coefficient thermistors, and 4 to 6 are terminals.

The case 1 is composed of a combination of a bottom member 11 and a cover member 12. The bottom member 11 and the cover member 12 are formed as molded articles of a suitable heat-resistant insulating plastic. Sixth
The figure is a plan view of the bottom member 11, and FIG. 7 is a cross-sectional view taken along the line C1-C1 in FIG. 111 is the inner bottom surface of the bottom member 11, 112 to 116
Is a projection protruding from the inner bottom surface 111. The protrusion 112 is the inner bottom
It is provided at the approximate center of 111, and the projections 113 and 114 and the projection 1
The reference numerals 15 and 116 are provided at both sides of the projection 112 at an interval. As described later, the protrusion 112 prevents the terminal from moving in a direction parallel to the electrode surfaces of the positive temperature coefficient thermistors 2 and 3.
The protrusions 113 and 114 serve as concave and convex fitting portions that prevent the terminal from moving in a direction perpendicular to the electrode surface of the positive temperature coefficient thermistor 2. The protrusions 115 and 116 support the PTC thermistor 2 at a certain interval with respect to the inner bottom surface 111 of the bottom member 11.
The number of projections 112 to 116 is arbitrary, and need not be limited to the number shown. Reference numerals 117 and 118 denote receiving portions projecting around the bottom member 11, and the cover member 12 is fitted and assembled to the receiving portions 117 and 118.

The positive characteristic thermistors 2 and 3 are the positive characteristic thermistor body 2
Electrodes (22, 23), (32, 33) on both sides in the thickness direction of 1, 31
Is provided. Among these positive temperature coefficient thermistors 2 and 3, the positive temperature coefficient thermistor 2 is provided for demagnetization, and the positive temperature coefficient thermistor 3 is provided for heating. The positive characteristic thermistors 2 and 3 have a structure in which a common terminal 5 of a flat plate made of a metal plate is sandwiched therebetween and overlapped with each other, and is elastically sandwiched between elastic terminals 4 and 6.

The terminals 4 and 6 are connected to the electrodes 23 and 32 of the thermistors 2 and 3, respectively.
It has contact portions 41 and 61 having a spring property to come into contact with the terminal 1 and terminal portions 42 and 62 led out of the case 1.

The terminal 5 has a contact portion 51 that is in common contact with the electrode 22 of the positive temperature coefficient thermistor 2 and the electrode 33 of the positive temperature coefficient thermistor 3 and a terminal portion 52 that penetrates the bottom member 11 of the case 1 and is led out.
And a detour section 53. These are formed in the same body by subjecting the same metal plate to press working or the like.

FIG. 8 is a front view of the terminal 5, and FIG. 9 is a side view of the same. The contact portion 51 has a notch 55 at one edge facing the inner bottom surface 111 of the bottom member 11 constituting the case 1.
The notch 55 is formed in a shape and position to be engaged with the projection 112 formed on the inner bottom surface 111.

The detour portion 53 is a narrow road having a width narrower than that of the contact portion 51, and is arranged on the side of the contact portion 51 with an interval G1. One end of the detour portion 53 is connected above the contact portion 51,
The other end is connected to the terminal part 52, and forms an electrical and thermal series circuit with the contact part 51 and the terminal part 52. In the embodiment, the detour portion 53 is floated from the surface of the contact portion 51 to prevent contact with the PTC thermistor 2. Further, in order to prevent the PTC thermistor 3 from coming into contact with the detour portion 53 floated as described above, a blocking side 54 is protruded from an edge of the contact portion 51 facing the detour portion 53.

Further, the detour portion 53 and the terminal portion 52 are provided with reinforcing portions 531 and 521 formed by concave or convex surfaces to increase the mechanical strength.
Are provided in a streak shape. It is preferable that the terminal 5 be entirely electroplated in order to supplement the mechanical strength.

In assembling, the common terminal 5 is fitted with a protrusion 112 having the notch 55 projecting from the inner bottom surface 111 of the bottom member 11. This allows
The contact portion 51 of the common terminal 5 is positioned in a state where movement in a direction parallel to the surfaces of the positive temperature coefficient thermistors 2 and 3 is prohibited. For this reason, an accident such as the contact portion 51 coming into contact with the bypass portion 53 does not occur, and the temperature rise of the terminal portion 52 is suppressed.

The inner bottom surface of the bottom member 11 is provided on the surface of the contact portion 51 of the common terminal 5.
Projections 113 and 114 projecting from 111 are in contact with each other. Thereby, movement in the direction orthogonal to the surface of the contact portion 51 is also prevented.

Moreover, the positive temperature coefficient thermistor 2 is received by the protrusions 115 and 116 and is held in a state of floating from the inner bottom surface 111. For this reason, the detour part due to vertical displacement
The contact of the positive temperature coefficient thermistor 2 with 53 can be avoided. In addition, contact of the PTC thermistor 2 with the inner bottom surface 111 does not occur, and the heat radiation characteristic is stably maintained at a constant value.

On the inner surface 121 of the cover member 12 facing the inner bottom surface 111, projections 122 and 123 projecting in the arrangement area of the positive temperature coefficient thermistor 3 and the contact portion 51 are provided in a strip shape. Protrusion 12
According to 2, 123, even if the positive temperature coefficient thermistor 2 is arranged in a state of contacting the cover member 12, the contact area is
A small contact area is formed by the projections 122 and 123. For this reason,
The effect of heating the cover member 12 by the positive temperature coefficient thermistor 2 is reduced, and the temperature rise of the cover member 12 is suppressed. at the same time,
The movement range of the contact portion 51 of the terminal 5 is limited by the projections 122 and 123. Therefore, even when an upward force F1 (see FIG. 2) is applied to the terminal portion 52 when the terminal 5 is attached to an external device, the movement of the terminal 5 is restricted by the projections 122 and 123, and Positioned in position. The positions and numbers of the projections 122 and 123 are arbitrary.

FIG. 10 shows a color television degaussing circuit using the PTC thermistor device according to the present invention, where C is the PTC thermistor device. Reference numeral 7 denotes an AC power supply, 8 denotes a power-on switch, and 9 denotes a degaussing coil. FIG. 11 shows the resistance-temperature characteristics of the thermistors 2 and 3, and FIG. 12 shows the time-current characteristics.

Assuming that the positive temperature coefficient thermistor 3 has no heating effect and the positive temperature coefficient thermistor 2 operates alone,
The resistance-temperature characteristic shown by the curve A in FIG. Therefore, an equilibrium point current shown by a curve IA in FIG. 12 flows through the degaussing coil 9. When a positive temperature coefficient thermistor 3 having a resistance temperature characteristic as shown by a curve B in FIG. 11 is thermally coupled to the positive temperature coefficient thermistor 2, the positive temperature coefficient thermistor 2 becomes
, And the temperature at which the operating temperature of the positive temperature coefficient thermistor 2 is higher than the temperature TA shifts to TB. Therefore, the resistance value of the positive characteristic thermistor 2 at the time of stable operation becomes the resistance value RB higher than the resistance value RA, and the equilibrium current flowing through the degaussing coil 9 becomes the
It decreases as shown by curve IB in FIG.

In order to reduce the equilibrium point current, it is necessary to raise the resistance value of the positive temperature coefficient thermistor 2 as high as possible. As the positive temperature coefficient thermistor 3, one having a higher resistance value and a higher switching temperature TS than the positive temperature coefficient thermistor 2 is used. used. Therefore, the common terminal 5 between the positive temperature coefficient thermistor 2 and the positive temperature coefficient thermistor 3 is heated at a considerably high temperature.

Here, in the present invention, since the above-described detour portion 53 is provided, even when the contact portion 51 of the terminal 5 is heated to a high temperature between the positive temperature coefficient thermistors 2-3, the contact portion 51 is connected to the terminal portion 52. Is suppressed by the bypass portion 53. For this reason, the heat generation temperature of the positive temperature coefficient thermistor rises, the temperature of the terminal section 52 decreases, and the equilibrium point resistance increases.
The residual current is reduced, and the heat-resistant design of the case 1 is facilitated.

In addition, since the projections 112 and the notches 55 are formed with concave and convex fittings between the inner bottom surface 111 of the bottom member 11 constituting the case 1 and the contact portions 51 of the terminals 5, the contact portions 51 of the terminals 5 are detoured. Department
The contact with the terminal 53 does not occur, and the temperature rise of the terminal portion 52 can be more reliably prevented.

<Effects of the Invention> As described above, according to the present invention, the following effects can be obtained.

(A) It is possible to provide a positive temperature coefficient thermistor device having a low residual current and excellent demagnetizing action when used in a degaussing circuit.

(B) The heat conduction from the contact portion to the terminal portion is suppressed by the detour portion, the temperature of the terminal portion is kept low, the thermal deterioration of the case is small, the heat-resistant design is easy, the power saving type and the electric characteristics are improved. An excellent PTC thermistor device can be provided.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of the positive temperature coefficient thermistor device according to the present invention, FIG. 2 is a sectional view taken along line A1-A1 in FIG. 1, FIG. 3 is a partial sectional view taken along line A2-A2 in FIG. Figure 2B
FIG. 5 is a partial cross-sectional view along the line B2-B2, FIG. 6 is a plan view of the bottom member 11, and FIG. 7 is a cross-sectional view along the line C1-C1 in FIG. , FIG. 8 is a front view of the terminal, FIG. 9 is a side view of the same, FIG. 10 is a demagnetization circuit diagram using the PTC thermistor device according to the present invention,
FIG. 11 is a resistance temperature characteristic diagram for explaining the operation of the degaussing circuit shown in FIG. 10, and FIG. 12 is a current decay characteristic diagram similarly. DESCRIPTION OF SYMBOLS 1 ... Case, 11 ... Bottom member 12 ... Cover member 111 ... Inner bottom surface 112-116 ... Protrusion 2, 3 ... Positive thermistor 4-6 ... Terminal 41, 51, 61 ... Contact part 42 , 52… 62… Terminal 53… Detour 55… Notch

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-208803 (JP, A) Japanese Utility Model Application Sho 62-55304 (JP, U) Japanese Utility Model Application Utility Model Sho 62-98202 (JP, U) (58) Field (Int.Cl. ⁶ , DB name) H01C 7/00-7/22

Claims (5)

(57) [Scope of request for utility model registration] 1. A positive temperature coefficient thermistor device comprising a case, two positive temperature coefficient thermistors housed in said case, and a plurality of terminals electrically connected to electrodes of said positive temperature coefficient thermistor, used for a degaussing circuit. The two positive temperature coefficient thermistors are superimposed on each other, and one of the terminals is disposed between the two positive temperature coefficient thermistors and is in contact with the electrodes of the two positive temperature coefficient thermistors. And a detour part, and a terminal part led out of the case, wherein the detour part is narrower than the contact part and is spaced apart from a side of the contact part. A PTC thermistor device, wherein one end is connected to one end of the contact portion and the other end is connected to the terminal portion so as to connect the contact portion and the terminal portion in series. 2. An uneven fitting portion between an inner bottom surface of the case and an edge of the contact portion.
4. The positive temperature coefficient thermistor device according to 1. 3. The positive temperature coefficient thermistor device according to claim 1, further comprising a projection on an inner bottom surface of said case for receiving said positive temperature coefficient thermistor. 4. The positive temperature coefficient thermistor device according to claim 1, further comprising a projection disposed on an inner bottom surface of said case so as to face a surface of said contact portion. . 5. The positive temperature coefficient thermistor device according to claim 1, wherein said bypass portion has a reinforcing portion formed by unevenness provided on a surface.