JPS60225495A - Device for fixing control circuit - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for supporting and fixing a control device for electrical equipment using a printed wiring board and a power transformer.

Conventional configuration and its problems Conventionally, electric devices such as microwave ovens that use a printed wiring board 5 and a power transformer 6 that supplies power to the printed wiring board 5 have a printed wiring board as shown in FIG. By directly electrically and mechanically fixing the power transformer 6 on the wiring board 5 by soldering or the like, and by fixing the printed wiring board 5 to the chassis 7, the power supply can be indirectly connected via the printed wiring board 5. A configuration in which the transformer 6 is fixed is used. However, with this configuration, the transformer 6 is not directly fixed to the chassis 7, so if the printed circuit board 5 is not made very firm, the printed circuit board 5 may break due to vibration during transportation or impact from falling. However, there was a problem that the printed base was cut.

Therefore, as shown in Figure 2, the transformer 6 is connected to the printed circuit board 5.
A configuration has been proposed in which the printed circuit board 5 is fixed to the top of the chassis 7 by soldering, and at the same time, the printed circuit board 5 is fixed to the top of the chassis 7 with screws or the like.

However, in the case of this configuration, although the printed circuit board s itself did not crack, another problem occurred when the transformer 6 and printed circuit board 5 were screwed together to the chassis 7, and the printed circuit board broke. Ta. This is because when soldering the transformer 6 to the printed circuit board 5, a small gap always occurs between the bottom of the transformer 6 and the printed circuit board 6. This is because when pressed, this K exerts a force to peel off the printed base. Because of this problem, conventionally, if the transformer 6 itself is not molded to the chassis 7, the large transformer 6, which can cause cracking of the printed circuit board 5, cannot be directly connected to the printed circuit board 5.
Connection was made using lead wires, but this method had the disadvantage that the cost of the transformer 6 was much higher than the direct soldering method, and the number of assembly steps was also increased.

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned conventional drawbacks, and aims to provide a method for mounting a transformer for a printed circuit board that has a simple structure, high reliability, and low cost.

Structure of the Invention In order to achieve the above object, the present invention includes a printed circuit board that mounts a control circuit in a main body, a power transformer that supplies power to the control circuit, and a support plate that supports and fixes the printed circuit board. The output terminals of the power transformer are directly connected to the printed circuit board by soldering, etc., and the legs of the power transformer are connected directly to the support plate by screws, etc., without going through the printed circuit board. Since the structure is fixed using a fixed method, regardless of the size and weight of the transformer, the printed circuit board is not subjected to extreme vibrations and shocks during transportation, and defects such as printed foil breakage sometimes occur when installing the transformer. This has the effect of being able to prevent things from happening.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 3, reference numeral 1 denotes the main body of the device, which has a heating chamber and the like (not shown) inside. 2 is a door that can open and close the front opening of the heating chamber. Reference numeral 3 denotes a control panel section which has an operation keyboard 4 and the like on its outer surface.

In FIG. 4, 5 is a printed circuit board, 6 is a power transformer that supplies power to the printed circuit board 5, and 7 is a chassis that supports and fixes the printed circuit board 5, the power transformer 6, etc.

The output terminal 12 of the power transformer 6 is directly connected to the printed circuit board 5 by soldering, and the printed circuit board 5 and the power transformer 6 are also mechanically connected by this soldering.

To install the power transformer 6, the legs 8 are fixed directly to the cut and raised portions 9 of the cable 77 with screws.At this time, in order to prevent the printed circuit board 5 from being screwed to the chassis 7 at the same time, A hole 10 and a notch 11 are provided. Therefore, in this part, the printed circuit board, 5
is fixed to the chassis 7 only indirectly via the power transformer 6 by being connected by soldering to the input/output terminals of a power transformer 60 fixed to the chassis.

The operation of the above configuration will be explained below.

The input/output terminals of the power transformer 6 are inserted into the connection holes provided on the printed circuit board 5 in the same way as other components, and after the usual soldering process, it is finished as a printed circuit board unit, and the chassis 7 is assembled. In this case, the connection to the chassis 7 can be made by simply screwing the mounting feet of the power transformer 6 in the vicinity of the power transformer 6.
Since the power transformer 6 itself is not directly screwed to the chassis 7, the power transformer 6 can only be fixed to the chassis 7 and 9, but when fixing the power transformer 6, a gap is created between the printed circuit board 5 and the power transformer 6. Even if it is soldered in a blank state, no excessive force will be applied to peel off the printed base. Also, since the weight of the printed circuit board 5 excluding the power transformer 6 is usually very light, the parts where the power transformer 6 is connected are indirectly connected to the chassis through soldering at the input/output terminals of the power transformer 6. 7 is sufficient for strength.

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

(1) The power transformer and the printed circuit board are electrically and mechanically connected together at the input/output terminals of the power transformer. Since the power transformer is fixed to the chassis and during transportation,
Even when shocks such as vibrations are applied, excessive force is not applied to the printed circuit board, causing problems such as cracking of the circuit board, and extremely high reliability can be obtained.

(2) The power transformer has a structure in which the input/output terminals are directly soldered to the printed circuit board without using lead wires, so in terms of cost, the transformer is fixed to the chassis separately and printed with lead wires. It is much cheaper than the method of connecting to the board, and the number of assembly steps can be reduced.

(3) Even when soldering is done with a gap between the power transformer and the printed circuit board, there is no need to apply excessive force to the printed foil when attaching it to the chassis, and there is no need to worry about the foil breaking.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional example, Fig. 2 is a perspective view showing a conventional example, Fig. 3 is an external view of a microwave oven showing an embodiment of the present invention, and Fig. 4 is a control circuit fixing device of the same. FIG. 5... Printed circuit board, 6... Power transformer, 7... Chassis, 8... Power transformer mounting foot, 9°゛°°゛° chassis. Cut-and-raised portion, 10... Hole of printed circuit board, 11...
...Notch on printed I board, 12...Input/output terminal of power transformer. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Scope of Claims] (1) A main body includes a printed wiring board that mounts a control circuit, a power transformer that supplies power to the control circuit, and a support plate that supports and fixes the printed wiring board; The input/output terminals of the power transformer are directly connected to the printed wiring board by soldering or the like, and the mounting legs of the power transformer are directly fixed to the support plate with screws or the like without intervening the printed wiring board. control circuit fixing device. @) The control circuit fixing device according to claim 1, wherein the mechanical connection between the printed wiring board and the power transformer is made only by soldering at the terminal portion. (3) To install the power transformer, make a notch hole in the printed wiring board at the foot and connect the power transformer to the support plate, so that the printed wiring board can only be indirectly fixed to the support plate. As configured