JP3401707B2 - Lightning arrester - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a lightning arrester for generating a discharge between conductors, and more particularly to a television receiver and a television integrated video tape recorder ( TVC
R) The present invention relates to a lightning arrester for preventing lightning of electric equipment such as R) and reducing noise of a power supply circuit. 2. Description of the Related Art Various types of lightning arresters for electric equipment have been manufactured mainly using a discharge gap.
(See Japanese Patent Application No. 09-359115). The caprister 10 is a CR composite component in which a resistor 8 and a capacitor 9 are connected in parallel to a discharge gap 6 composed of primary and secondary electrodes separated from each other, and is manufactured for lightning strike prevention in a power supply circuit. I have. This lightning arrester further includes a capacitor 11 and a filter 12 for removing noise generated on the power supply circuit side. The capacitor 11 is connected in parallel to both ends of the caprystar 10, and the filter 12 formed of two coils 12 a and 12 b called a bead core is connected in series to one end of the caprystar 10. When the lightning arrester configured as described above is used for a popular television, it is connected between the primary power supply side A and the secondary power supply side B shown in FIG. That is, the commercial power supply 1 on the primary power supply side A is:
A current is supplied to the rectifier circuit 2, and the current rectified by the rectifier circuit 2 is supplied to the switching power supply circuit 3. The output current from the switching power supply circuit 3 is supplied to each load circuit. The television tuner 4 is connected to the commercial power supply 1 via a lightning arrester.
Is in a non-conductive state, and the tuner 4 and the commercial power supply 1 are insulated. In addition, Capystar 10 and Tuner 4
Since the filter 12 is interposed between and, the high frequency component can be cut. The ground E1 forming the rectifier circuit 2 and the ground E2 connected between the rectifier circuit 2 and the switching power supply circuit 3 via the capacitor C mean the ground on the primary power supply side A and have the same potential. It has become. Further, a ground E3 constituting the switching power supply circuit 3 and a ground E provided in the tuner 4 are provided.
4 and E5 mean the ground of the secondary power supply side B and have the same potential. [0004] According to the above configuration, from foreign by lightning strikes, etc.
Of the surge arrester flows into the antenna input terminal 4a of the tuner 4 from an antenna (not shown), the discharge gap 6 of the lightning arrester connected to the tuner 4
Are conducted by discharging, and the surge voltage is released to the commercial power supply 1, thereby preventing the load circuits of the product from being destroyed. In addition, when the switching power supply circuit 3 operates, noise generated by switching between the positive and negative electrodes alternately causes:
From the ground E3 side of the switching power supply circuit 3 to the tuner 4
Is reduced by the filter 12 even if it flows into the side of the ground E4. The above-mentioned conventional lightning arrester includes a capister 10 including a discharge gap 6, a resistor 8 and a capacitor 9, a filter 11 including a capacitor 11 and two coils 12a and 12b. 12
Is provided, the number of parts is considerably large, and the circuit configuration is complicated. For this reason, mounting on the power supply circuit is difficult in terms of design and manufacturing, and there is a disadvantage that the manufacturing cost is inevitably increased. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a lightning arrester capable of preventing electric equipment from being damaged by a lightning strike with a simple configuration and reducing noise generated in an electric circuit. The purpose is. [0007] To achieve the above object, the present invention provides a rectifier for rectifying commercial AC power of a commercial power supply.
The commercial power in the primary side circuit having at least a circuit.
Primary conductor connected to a connection point between a source and the rectifier circuit
When, a secondary conductor connected to a secondary circuit having at least an antenna input terminal, and arranged apart from each other by a predetermined distance, using the separating portion as a discharge gap, this
Discharge gap is surge voltage from outside due to lightning strike etc.
Discharge action due to the flow of gas into the antenna input terminal
A lightning arrester configured to conduct by
DC power supplied from the rectifier circuit
A switching power supply circuit for generating a supply current;
Connected between the side circuit and the secondary circuit,
Diode anode with structure capable of withstanding voltage
To the secondary conductor and the cathode to the switching
Ground for the secondary side circuit at the same potential as the ground of the power supply circuit
It is characterized by being connected to each end . An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an electric circuit diagram showing an example in which a lightning arrester according to the present invention is used for a television. The lightning arrester 5 is provided in an AV device such as a television or a TVCR to protect the AV device from a surge voltage due to a lightning strike and to reduce noise generated in a power supply circuit. . The lightning arrester 5
Will be described as an example provided on the power supply circuit side in the same way as the electric circuit of the television shown in FIG. This lightning arrester 5
Is a discharge gap 6 with a diode 7 connected to it.
It is designed to be mounted on a printed circuit board constituting an electronic circuit. The discharge gap 6 has a pair of electrodes, which are conductors, formed on a surface of a dielectric made of a dielectric material such as a ceramic base, and has primary and secondary electrodes 6a and 6b.
Are connected to lead wires for connection to a printed board (not shown). In this embodiment, the gap between the electrodes 6a and 6b of the discharge gap 6 is set to 1.6 mm for a television, and a TVCR requiring double insulation is adapted to UL (Underwriters Laboratories) standard of the United States. It is 2.6 mm. This UL
According to the standard, the discharge voltage between conductors is set to 1.3 KV to ensure safety. Therefore, even if it is used for other electric devices including TVs, make it so that the conductors do not conduct at 2-3 KV. Is preferred. The diode 7 is a silicon diode 7 made of a silicon material, and has a structure capable of sufficiently withstanding a so-called high voltage surge voltage due to a lightning strike, and has a pair of connection lead wires. When mounting the diode 7 and the discharge gap 6 on a printed circuit board, a lead wire is inserted into each through hole and soldered so that they are connected in series. For example, when this lightning arrester 5 is provided in a television electric circuit, as shown in FIG.
A discharge gap 6 and a diode 7 are connected in series between the commercial power source 1 and the tuner 4. Here, the primary electrode 6a of the discharge gap 6 is connected between the commercial power supply 1 and the rectifier circuit 2, while the anode of the diode 7 is connected to the secondary electrode 6b. The cathode of the diode 7 is connected to the ground E4 and the tuner 4 side. Thus, the discharge gap 6 of the lightning arrester 5
Is normally in a non-conductive state, the commercial power supply 1 on the primary power supply side A and the tuner 4 on the secondary power supply side B are insulated. For this reason, a surge voltage is generated from an antenna (not shown) due to a lightning strike or the like from the antenna input terminal 4 of the tuner 4.
a, the discharge gap 6 connected to the tuner 4 becomes conductive by discharge, and
Release surge voltage. Therefore, since this surge voltage does not flow into each load circuit side of the product, their destruction is prevented. By the way, the discharge gap 6 has a small floating capacitance because the primary electrode 6a and the secondary electrode 6a are separated from each other at a predetermined interval. In this state, when the switching power supply circuit 3 operates, when noise is generated by switching between the positive and negative electrodes alternately, the noise is guided from the earth E3 side to the earth E4 side of the tuner 4 and is discharged through the discharge gap 6 to the primary. There is a problem that the noise is transmitted to the power supply side A and affects the load circuit to cause noise. In the lightning arrester 5 of this example, since the diode 7 is provided in the preceding stage of the discharge gap 6, even if the noise of the switching power supply circuit 3 is guided from the earth E3 side to the earth E4 side of the tuner 4, it is reduced by the diode 7. Therefore, the flow to the primary power supply side A is reduced . Therefore, the influence of the noise on the load circuit is greatly reduced. FIG. 2 is an electric circuit diagram showing a modification of the lightning arrester. This lightning arrester has a diode 7 connected in series to a caprister 10 and is provided in an electric circuit of a television shown in FIG. The caprystar 10 is a conventionally known CR composite component in which a discharge gap 6, a resistor 8, and a capacitor 9 are connected in parallel. In this CR composite component, a diode 7 is connected to one end to constitute a lightning arrester. When this lightning arrester is provided in the electric circuit of the television shown in FIG. 1, a caprister 10 and a diode 7 are connected in series between the commercial power source 1 and the tuner 4. This surge arrester also has the same features as described above, when a surge voltage flows into the tuner 4 due to a lightning strike or the like, the discharge gap 6 of the caprister 10 becomes conductive by discharging, and the surge voltage is released to the commercial power supply 1. Similarly, the load circuit of the product is prevented from being destroyed. Switching power supply circuit 3
Is prevented from flowing into the primary power supply side A by the diode 7, and the effect of the noise on the load circuit is greatly reduced. In addition,
In the above-described embodiment, the structure in which the lightning arrester is interposed between the commercial power supply 1 of the television and the tuner 4 has been described. However, the mounting position of this lightning arrester is not limited to this. Alternatively, it may be provided between a circuit (secondary circuit) connected to the secondary power supply and the commercial power supply. As described above, the present invention provides a lightning strike and the like.
Surge voltage flows into the antenna input terminal
In the case, the primary conductor and the secondary conductor
The discharge gap provided between the two
Voltage to the commercial power supply, causing the product load circuit to break.
Destruction can be reliably prevented. Also, the primary side circuit and 2
The operation of the switching power supply circuit connected to the secondary circuit
The noise generated during operation is grounded in the switching power supply circuit.
If the noise flows into the ground side of the secondary circuit from the
Is reduced by the diode and flows into the primary circuit.
The load circuit is not affected by noise.
It is greatly reduced. Therefore, in this lightning arrester,
Instead of a capacitor or filter for removing noise,
Although it has a simplified configuration with only a
The effect of noise can be greatly reduced. And the diode is
Has a structure that can withstand even surge voltage
So there is no destruction.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an electric circuit diagram showing an example in which a lightning arrester according to an embodiment of the present invention is used for a television. FIG. 2 is an electric circuit diagram showing a modification of the lightning arrester. FIG. 3 is an electric circuit diagram showing an example in which a conventional lightning arrester is used for a television. [Description of Signs] 6 Discharge gap 6a Primary side conductor 6b Secondary side conductor 7 Diode A Primary side circuit B Secondary side circuit E4 Ground end

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02H 9/00-9/06 H01T 4/10 H01G 1/11

Claims (1)

(57) [Claims] [Claim 1] Rectification for rectifying commercial AC power of a commercial power supply
The commercial power in the primary side circuit having at least a circuit.
Primary conductor connected to a connection point between a source and the rectifier circuit
When, a secondary conductor connected to a secondary circuit having at least an antenna input terminal, and arranged apart from each other by a predetermined distance, using the separating portion as a discharge gap, this
Discharge gap is surge voltage from outside due to lightning strike etc.
Discharge action due to the flow of gas into the antenna input terminal
In the lightning arrester configured to conduct by each of the load circuits, each of the load circuits is controlled by DC power supplied from the rectifier circuit.
A switching power supply circuit for generating a supply current to the
A diode connected between a primary circuit and the secondary circuit and having a structure capable of sufficiently withstanding the surge voltage
Is connected to the secondary-side conductor, and the cathode is connected to the switch.
The secondary circuit having the same potential as the ground of the switching power supply circuit;
A lightning arrester characterized by being connected to the ground end of each .