JP2006147361A - Jack and relay cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a jack capable of interrupting overcurrent even in the case of a short circuit in wiring and the like before arrival of electric current in a circuit and to provide a relay cable having the jack. <P>SOLUTION: A DC jack 12 is provided with a pin 20 and a terminal 22. The pin 20 is electrically connected via contact with a DC plug 16 when the DC plug 16 is inserted. The terminal 22 is constructed of a first conductor layer 24, a power interruption element (poly-switch) 26, and a second conductor layer 28. The first conductor layer 24 is layered in a part slightly projecting to the pin 20 side of the second conductor layer 28 and brought into contact with the DC plug 16 to be electrically connected when the DC plug 16 is inserted. The second conductor layer 28 is electrically connected with a circuit 18. The poly-switch 26 is layered between the first conductor layer 24 and the second conductor layer 28, and the second conductor layer 28 is not directly connected with the DC plug 16 electrically, but electrically connected only via the first conductor layer 24 and the poly-switch 26. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

TECHNICAL FIELD OF THE INVENTION

  The present invention relates to a jack and a relay cable.

  Conventionally, a self-recovery overcurrent protection element has been used to protect a circuit from overcurrent. There is a polyswitch as a kind of this self-recovery type overcurrent protection element. (PolySwitch is a product name sold by Raychem and is a polymer PTC (Positive Temperature Coefficient). ) Also called element). Unlike a fuse, a polyswitch is a device having a structure in which a conductive polymer sheet is sandwiched between two metal electrode foils, and is mounted on a circuit board or the like of an electronic device by direct lead attachment or surface mounting. If an overcurrent flows due to this circuit short-circuiting, the polyswitch is heated and the resistance value increases rapidly. Thereby, the overcurrent is interrupted and the circuit is protected from the overcurrent. Then, once the circuit power is turned off and the temperature of the polyswitch decreases, the resistance value automatically returns (returns automatically).

As an example of a technique using this polyswitch, Patent Document 1 discloses that a first conductive plate welded to a battery anode and an opening into which the battery anode is inserted are stacked on the conductive plate. A polyswitch, an opening into which the battery anode is inserted, a second conductive plate stacked on the polyswitch, and an opening into which the battery anode is inserted. A conductive member including a polyswitch composed of an insulator laminated on a plate, wherein the portion of the first conductive plate welded to the anode of the battery is recessed inward. Is disclosed.
JP 2003-272607 A

  By the way, a jack for supplying power to a circuit such as a DC jack is mounted on a substrate by direct lead attachment or surface mounting. Conventionally, for example, when a short circuit occurs before the current reaches the circuit, such as between the contacts of the DC jack to the circuit board or between wirings in the DC cable, the polyswitch on the circuit board has an overcurrent. There was a problem that could not be blocked. Furthermore, if the detection of overcurrent is delayed, the circuit and cable are damaged by heating, which causes a fire.

  The present invention has been made in view of such circumstances, and provides a jack capable of interrupting overcurrent even when a short circuit occurs in a wiring or the like before the current reaches the circuit, and a relay cable including the jack. For the purpose.

  In order to achieve the above object, a jack according to claim 1 is a jack for inputting electric power supplied from a plug to an electronic device, and a first conductor layer electrically connected to the plug; A power interrupting element that is attached to the first conductor layer, is electrically connected to the plug only through the first conductor layer, and interrupts overcurrent, and is attached to the power interrupting element. And a second conductor layer electrically connected to an internal circuit of the electronic device and electrically connected to the plug only through the first conductor layer and a power cut-off element. .

  According to the jack of the first aspect, even when the short circuit occurs in the portion before the current reaches the power interruption element on the circuit board, such as between the contacts of the jack to the circuit board, the overcurrent is interrupted. can do.

  According to a second aspect of the present invention, in the jack according to the first aspect, the power cut-off element is a polyswitch. The second aspect of the present invention limits the type of power interruption element to a polyswitch.

  A relay cable according to a third aspect includes the jack according to the first or second aspect.

  According to claim 3, since the relay cable itself has a function of interrupting the overcurrent, for example, even when the relay cable is short-circuited, the relay cable is damaged by the overcurrent, a fire due to heating, etc. Can be prevented.

  According to the present invention, it is possible to cut off overcurrent even when a short circuit occurs before the current reaches the power cut-off element on the circuit board, such as the contacts of the jack to the circuit board or cables. It is possible to increase the safety of electronic devices. Furthermore, since there is no need to mount a polyswitch on a circuit as in the prior art, the number of components mounted on a circuit board can be reduced, and the circuit can be downsized.

  Hereinafter, preferred embodiments of a jack and a relay cable according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a perspective view showing a relay cable according to an embodiment of the present invention. The relay cable 10 includes a DC jack 12 that is connected to a DC plug and receives power supply, and a plug 14 that is connected to an electronic device.

  FIG. 2 is a cross-sectional view showing the DC jack according to the first embodiment of the present invention. As shown in FIG. 2, the DC jack 12 is connected to a DC plug 16 connected to a power source, and supplies power to the circuit 18.

  The DC jack 12 includes a pin 20 and a terminal 22. The pin 20 is electrically connected by contacting the DC plug 16 when the DC plug 16 is inserted. The terminal 22 includes a first conductor layer 24, a power interruption element (polyswitch) 26, and a second conductor layer 28. The first conductor layer 24 is laminated in a portion slightly protruding on the pin 20 side of the second conductor layer 28, and is in contact with and electrically connected to the DC plug 16 when the DC plug 16 is inserted. The The second conductor layer 28 is electrically connected to the circuit 18. The polyswitch 26 is laminated between the first conductor layer 24 and the second conductor layer 28, and the second conductor layer 28 is not directly electrically connected to the DC plug 16, and the first conductor layer 24 and Electrical connection is made only through the polyswitch 26.

  When the DC plug 16 is inserted into the DC jack 12, the pin 20 and the first conductor layer 24 come into contact with each other, and power is supplied to the circuit 18. When a short circuit occurs on the wiring to the circuit 18 or the circuit 18 (for example, between the points A and B in FIG. 2), an overcurrent flows through the terminal 22, so that the resistance of the polyswitch 26 increases rapidly. Overcurrent is cut off. This protects the circuit 18 from overcurrent. When the power is turned off and the temperature of the poly switch 26 is lowered, the resistance value of the poly switch 26 is automatically restored.

  According to this embodiment, even when a short circuit occurs on the wiring between the DC jack 12 and the circuit 18 (for example, between point A and point B in FIG. 2), overcurrent can be interrupted. Moreover, according to this embodiment, the function which interrupts | blocks an overcurrent can be added to relay cable 10 itself. Therefore, it is not necessary to mount the polyswitch on the circuit as in the prior art, and the number of components mounted on the circuit board can be reduced.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view showing a DC jack according to the second embodiment of the present invention. In FIG. 3, the DC plug 16 and the circuit 18 shown in FIG. 2 are omitted.

  The DC jack 12 of this embodiment includes a pin 40 and a terminal 42. The pin 40 is electrically connected by contacting the DC plug 16 when the DC plug 16 is inserted. The terminal 42 includes a first conductor layer 44, a power interruption element (polyswitch) 46, and a second conductor layer 48. A portion of the first conductor layer 44 protrudes toward the pin 40, and contacts the DC plug 16 and is electrically connected when the DC plug 16 is inserted. The first conductor layer 44 extends to the bottom side (right side in the figure) of the DC jack 12, and the polyswitch 46 is laminated near the end thereof. A second conductor layer 48 is laminated on the opposite surface of the polyswitch 46 to the first conductor layer 44. The second conductor layer 48 is electrically connected to the circuit 18. Further, the second conductor layer 48 is not directly electrically connected to the DC plug 16, and is electrically connected to the DC plug 16 only through the first conductor layer 44 and the polyswitch 46. As a result, as in the above embodiment, overcurrent can be interrupted even if a short circuit occurs before the current reaches the circuit.

  Next, a third embodiment of the present invention will be described with reference to FIGS. 4 is a sectional view showing a DC jack according to a third embodiment of the present invention, and FIG. 5 is a front view thereof. In FIG. 4, the DC plug 16 and the circuit 18 shown in FIG. 2 are omitted.

  The DC jack 12 of this embodiment includes a pin 60 and a terminal 62. In addition, the code | symbol 64 in a figure is a pin support member which supports the pin 60. FIG. The pin 60 is electrically connected by contacting the DC plug 16 when the DC plug 16 is inserted. The terminal 62 includes an inner peripheral conductor 66, a power interruption element (poly switch) 68, and an outer peripheral conductor 70.

  FIG. 6 is an exploded perspective view showing the DC jack of the present embodiment. As shown in FIG. 6A, the outer peripheral conductor 70 has a cylindrical shape and is electrically connected to the circuit 18. The poly switch 68 is laminated on the inner surface of the outer peripheral conductor 70. Further, as shown in FIG. 6B, the inner peripheral conductor 66 is made of an elastic conductor, and slits (four in the example of FIGS. 5 and 6B) are formed on the side surface. It is substantially cylindrical. As shown in FIG. 5, both end portions of the inner peripheral conductor 66 are bonded to the inner surface of the polyswitch 68, and the central portion is curved toward the pin 60 side.

  As shown in FIGS. 4 and 5, the inner peripheral conductor 66 contacts and is electrically connected to the DC plug 16 when the DC plug 16 is inserted. The outer peripheral conductor 70 is not directly electrically connected to the DC plug 16, and is electrically connected to the DC plug 16 only through the inner peripheral conductor 66 and the poly switch 68. As a result, as in the above embodiment, overcurrent can be cut off even if a short circuit occurs before the current reaches the circuit.

  The present invention is not limited to a DC jack or a DC power supply relay cable, but may be applied to other input / output terminals, relay cables, signal lines that require a protection function against overcurrent, and the like. it can.

The perspective view which shows the relay cable which concerns on one Embodiment of this invention Sectional drawing which shows DC jack which concerns on the 1st Embodiment of this invention Sectional drawing which shows DC jack concerning the 2nd Embodiment of this invention Sectional drawing which shows DC jack concerning the 3rd Embodiment of this invention Front view showing a DC jack according to a third embodiment of the present invention. The perspective view which decomposes | disassembles and shows the DC jack which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Relay cable, 12 ... DC jack, 14 ... Plug, 16 ... DC plug, 18 ... Circuit, 20 ... Pin, 22 ... Terminal, 24 ... First conductor layer, 26 ... Power interruption element (polyswitch), 28 2nd conductor layer, 40 ... pin, 42 ... terminal, 44 ... 1st conductor layer, 46 ... power interruption element (polyswitch), 48 ... 2nd conductor layer, 60 ... pin, 62 ... terminal, 64 ... Pin support member, 66 ... Inner peripheral conductor, 68 ... Power interruption element (polyswitch), 70 ... Outer peripheral conductor

Claims (3)

A jack for inputting electric power supplied from a plug to an electronic device,
A first conductor layer electrically connected to the plug;
A power interrupting element attached to the first conductor layer, electrically connected to the plug only through the first conductor layer, and interrupting overcurrent;
A second conductor attached to the power cutoff element, electrically connected to an internal circuit of the electronic device, and electrically connected to the plug only through the first conductor layer and the power cutoff element Layers,
Jack characterized by comprising.   The jack according to claim 1, wherein the power cut-off element is a polyswitch.   A relay cable comprising the jack according to claim 1.

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