JPH0519984Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an electronic device, and more specifically, to an electronic device that integrally includes a power supply circuit and an amplifier circuit, such as an amplifier device in a car audio device. This relates to the chassis of the device.

[Conventional technology]

2. Description of the Related Art Conventionally, as an amplifier device for car audio as an electronic equipment device, an amplifier device shown in, for example, an exploded perspective view in FIG. 3 and a sectional view in FIG. 4 is known.

Here, as shown in the figure, a conventional amplifier device 1
The structure includes a heat sink 4 which integrally forms the mounting plate part 3, which forms the main part of the chassis 8 of the amplifier device 1, a pair of side plate chassis 5 that close the open side surfaces of the heat sink 2, and the heat sink 2 and the pair of side plate chassis 5. a chassis 8 consisting of a bottom chassis 6 in the form of a single plate shown at the top in the figure, which covers an open surface surrounded by a side panel chassis 5; and a power supply circuit housed within the chassis 8 and serving as a DC-DC converter. An electronic component 10 such as a transformer forming the section 9 and an electronic component 12 such as a power transistor, semiconductor, resistor, capacitor, etc. forming the amplifier circuit section 11 are arranged separately, and the wiring pattern section is also arranged as a power supply circuit. The circuit board 13 is formed by separating the section 9 and the amplifier circuit section 11, and the circuit board 13 housed in the chassis 8 is shielded by the bottom chassis 6.

[Problem that the invention attempts to solve]

However, in the conventional amplifier device 1 having the above-described configuration, the bottom chassis 6 is formed of a single metal plate that shields the power supply circuit 9 and the amplifier circuit 11 housed in the chassis 8. Even if the electronic components 10 and 12 constituting the power supply circuit section 9 and the amplifier circuit section 11 are arranged separately for each circuit on the board 13, the power supply circuit forming the DC-DC converter is 9
The leakage magnetic flux from the DC-DC transformer 10 becomes a radiation wave shown by arrow A and is radiated to the bottom chassis 6.
A current B is induced, and a reflected wave C shown by arrow c in the figure is generated from this induced current B, and the reflected wave C is generated in the amplifier circuit section 1.
The reflected wave C affects the electronic components 12 such as semiconductors and resistive capacitors 1 and the pattern surface (not shown) of the circuit board 13, causing noise generation and deterioration of total harmonic distortion in the amplifier circuit section 11. The following problem occurred.

In addition, as a countermeasure to this problem, DC-DC
Countermeasures have been taken, such as shielding the transformer or attaching permalloy as a magnetic material to the bottom chassis located on the top of the DC-DC transformer, but in this case, it is necessary to provide a shield or a part to which permalloy is attached. However, new problems have arisen in that the cost is high and the number of assembly steps is increased.

[Means for solving problems]

The present invention was devised in order to solve the above-mentioned problems, and the means thereof is to house and arrange a circuit board on which electronic components constituting a power supply circuit and electronic components constituting an amplifier circuit are provided. The electronic device includes a chassis that covers a circuit board of the electronic device, a first shield that covers the power supply circuit and the electronic components that make it up, and a second shield that covers the amplifier circuit and the electronic components that make it up. The first and second shielding parts are arranged apart from each other.

[Effect]

The chassis facing the power supply circuit section and the amplifier circuit section are made up of two independent parts, and are arranged separately from each other, so that reflections caused by induced current due to radiation waves generated in the power supply circuit section are avoided. Waves are generated only on the power supply circuit side and are prevented from occurring on the amplifier circuit side.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is an exploded perspective view showing an amplifier device as an embodiment of an electronic device according to the present invention, and FIG. 2 is a plan view thereof.

As illustrated, the amplifier device 20 constitutes the main part of the chassis 21. A heat sink 22 that integrally forms a mounting plate 23 and a heat sink 24;
A pair of side plate chassis 25 that closes the side surfaces of the heat sink 22, and two independent first and second shield plates 26 and 2 that cover the opening surface of the case formed by the side plate chassis 25 and the heat sink 22.
A chassis 21 is formed from 7, and within this chassis 21, a power supply circuit section 28 and its respective electronic components 30,
In addition, a circuit board 32 on which the amplifier circuit section 29 and its electronic components 31 are disposed on dispersed pattern surfaces is housed and arranged to constitute the amplifier device 20.

Here, the first shielding plate 26 is connected to a power supply circuit 28 which acts as a DC-DC power supply circuit for a circuit board 32 housed in the chassis 21, for example, a DC-DC power supply circuit.
so as to cover electronic components 30 such as DC transformers, etc.
One end 26a is locked to one side plate chassis 25, and the other end 26b is fixed to one side plate chassis 25 with screws or the like. A first shielding plate 26 is installed to cover electronic components 31 such as semiconductors, power transistors, and capacitors located on the side.
Similarly, one ends 27a and 27b are respectively locked to the side plate chassis 25 and fixed by screws or the like, but in this disposed state, the first shielding plate 26 and the second shielding plate 26 The shielding plates 27 have a structure in which opposing sides 26c and 27c are spaced apart from each other with a predetermined gap d between them.

Next, the first chassis as a bottom chassis that covers the circuit board 32, which is a characteristic configuration of the present invention.
To explain the effect of arranging the second shielding plates 26 and 27 independently and apart from each other, as shown in FIGS. 1 and 2, the DC-DC power supply of the amplifier device 20 The power supply circuit 28 serving as the circuit
Due to leakage magnetic flux A shown by arrow A leaking from the DC-DC transformer 30, an induced current B shown by arrow B is induced on the first shielding plate 26 surface, and further,
Due to the action of this induced current B, a reflected wave C shown by an arrow C is emitted toward the electronic component 30 disposed on the circuit board 32 and its circuit pattern surface (not shown). However, when this reflected wave C is generated, the second shielding plate 2 that covers the amplifier circuit section 29
7 is arranged and fixed at a distance from the first shielding plate 26 with a gap d, so that the DC-DC transformer 3
The induced current B induced by the zero leakage magnetic flux A is not transmitted to the second shielding plate 27, and as a result, the generation of reflected waves C is prevented on the amplifier circuit 29 side.

In the figure, numerals 34 and 35 indicate input terminals to the power supply circuit section 28.

[Effect of idea]

Therefore, according to the present invention, in an electronic device in which a power supply circuit section and an amplifier circuit section are formed on the same circuit board and housed in the same chassis, a shielding plate arranged and fixed opposite to the circuit board is provided. , the power supply circuit section and the amplifier circuit section are constructed as two independent parts, and their opposing sides are arranged apart from each other, so that leakage magnetic flux generated in the power supply circuit section causes damage to the amplifier circuit section. This provides the excellent effect of being able to prevent adverse effects on the environment with a simple and inexpensive configuration.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view showing an amplifier device for an electronic device according to the present invention, Fig. 2 is a plan view thereof, Fig. 3 is an exploded perspective view of a conventional amplifier device, and Fig. 4 is a sectional view of Fig. 3. It is. 20... Amplifier device, 26... First shielding plate,
27...Second shielding plate, 28...Power circuit section, 2
9...Amplification circuit section, 30, 31...Electronic component, d
……gap.

Claims (1)

[Scope of utility model registration request] In an electronic equipment device that houses and arranges a circuit board that includes electronic components that constitute a power supply circuit and electronic components that constitute an amplifier circuit, a chassis that covers the circuit board of the electronic equipment device constitutes the power supply circuit. a first shielding section that covers electronic components constituting the amplifier circuit; and a second shielding section that covers electronic components constituting the amplifier circuit, and these shielding sections are arranged at a distance from each other. Electronic equipment equipment.