JP2009103391A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To resolve problems that, when there is a leak point of an isometric voltage, a high voltage power supply for adding an air cleaning function to an air conditioner is used and an output high voltage lead wire is connected to a relay connector, when a position of the leak point approaches a metal case or it approaches the metal case via a structure formed of a high dielectric constant, when the metal case is charged by a high voltage leak current and the metal case approaches a conductive pattern of a printed circuit board, and when a discharge phenomenon from the metal case occurs, and circuits and parts on the printed circuit board cause malfunctions due to its dv/dt. <P>SOLUTION: In a structure, part of the metal case 3 is cut upward to form a shape easily causing a charge concentration, and made to contact with a discharge pattern 8 composed of copper foil on the printed circuit board 1. The discharge pattern is connected to a control ground pattern 7 of a circuit by a resistor 9 of a certain value, and the ground pattern is directly connected to the ground of an output supply of a power circuit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an air conditioner having a high voltage power supply device for an air cleaning function.

  A conventional air conditioner has a structure in which a primary circuit portion of a printed circuit board is surrounded by a case-shaped metal in order to prevent the spread of fire when an unsafe condition such as ignition or smoke of an electrical component occurs.

  Moreover, in order to add an air purifying function to the air conditioner, a high voltage power supply device is provided, and the negative current is generated by the discharge current flowing between the electrodes by connecting the output of the high voltage power supply device to the electrodes.

  FIG. 2 is a structural diagram of a metal case-shaped electronic control device of an air conditioner that prevents the spread of fire due to component ignition or the like.

  The printed circuit board 1 on which electronic components are mounted has a structure in which the solder surface is sandwiched between the flame-retardant resin case 2 and the component surface is sandwiched between the metal case 3. By having a structure in which the substrate is sandwiched between cases, asphyxiation is performed.

  Here, in order to add the function for the air purifier to the air conditioner, the high voltage power source 10 is required. The high voltage power source 4 is connected to the discharge electrode 6 by a high voltage lead wire 5. It is a mechanism that cleans the indoor air by charging dust floating in the air by negative ions released by the discharge electrode and adsorbing it on the circulating air by the air conditioner and adsorbing it to the air filter of the air conditioner.

At this time, when there is a high-pressure leak point where the high-voltage lead wire is connected by the relay connector 11, the position of the high-pressure leak point is close to the metal case 3, or a structure made of a material having a high dielectric constant When close to the metal case via an object, the metal case 3 is charged by a high-voltage leakage current. Further, when the metal case 3 is close to the conductive pattern 7 of the printed circuit board 1, a discharge phenomenon occurs when the charge amount of the metal case 3 reaches a dielectric breakdown voltage determined by the distance between the metal case 3 and the conductive pattern 7. . When the discharge phenomenon occurs, a circuit or component on the printed circuit board may malfunction due to the dv / dt.
JP 2006-12495 A JP 2005-51433 A

  In the configuration described in Patent Document 1, the metal casing and the discharge pattern are electrically connected by screws, and the discharge pattern is connected by the ground pattern and RC, thereby destroying the electronic component due to static electricity charged in the casing. Electrostatic discharge structures such as electronic devices that prevent the above are described.

  The configuration described in Patent Document 2 is a configuration of a camera unit that effectively removes static electricity applied to the housing by a structure in which a claw-shaped conductor extending from the housing is brought into contact with an electrostatic ground of an internal circuit. It is described to do.

In the above-described electrostatic discharge structure of an electronic device according to the conventional technique, the casing and the circuit board are mechanically fixed with screws and electrically connected to the discharge pattern, and the conductivity with the casing is maintained. To do this, it was necessary to perform mechanical fixing.

  In addition, the configuration of the camera unit has a structure in which a part of the housing is in contact with the discharge pattern, and there is a possibility that a sufficient contact structure with the discharge pattern cannot be maintained depending on the structure and variation in installation.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object of the present invention is to prevent malfunction of a circuit and destruction of parts by surely reducing dv / dt due to high voltage discharge with a simple structure.

  In order to solve the above problems, an air conditioner according to the present invention is an electronic control device configured to sandwich and store a printed circuit board between a metal case and a resin case. And a structure in which the copper foil is exposed by removing the resist at the contact portion of the pattern and contacting the discharge pattern configured by the copper foil on the printed circuit board, and the discharge pattern is a circuit control The ground pattern is connected with a resistor having a constant value, and the ground pattern is directly connected to the output source ground of the power supply circuit.

  The electronic control device for an air conditioner according to the present invention has a simple structure that does not require a fixing operation even when a metal case is charged due to the influence of a high-voltage power supply, but resists a positively stable GND pattern from a specific position. By reliably connecting through and discharging stably, dv / dt due to high-voltage discharge can be mitigated to prevent malfunction of the circuit and component destruction.

  The present invention provides a high voltage power supply device for adding an air cleaning function, and connects the output of the high voltage power supply device to electrodes so that a low leakage current flows between the electrodes to generate negative ions. In an air conditioner that has a structure that surrounds the primary circuit part of the printed circuit board with a case-shaped metal in order to prevent the spread of fire in the event of unsafe conditions such as smoke, the printed circuit board is sandwiched between a metal case and a resin case. In the electronic control device configured to be housed, a part of the metal case is cut off at an acute angle to make it easy to concentrate charges, and is in contact with the discharge pattern formed by the copper foil on the printed circuit board. The resist is removed to expose the copper foil, and the discharge pattern is connected to the control ground pattern of the circuit with a certain resistance. In addition, the ground pattern is directly connected to the output source ground of the power supply circuit, and even when the metal case is charged, the ground pattern is positively discharged to a stable GND pattern. Circuit malfunction and component destruction can be prevented.

(Embodiment 1)
FIG. 1 is a structural diagram for preventing malfunction in Embodiment 1 of the present invention. In this embodiment, the metal case 2 sandwiched from the component surface of the printed circuit board 1 is cut out to form an edge portion while having a simple structure in which the printed circuit board is sandwiched and stored between the metal case and the resin case. 1 has a structure in contact with the discharge-dedicated pattern 8 wired on the substrate 1.

  Further, the discharge dedicated pattern 8 is connected to a dedicated GND pattern 12 directly connected to the power supply output of the circuit by a resistor 9. As a result, since the structure is simple, an operation such as mechanical fixing is not required, and when the metal case 3 is charged, the discharge location is specified because charges are concentrated on the edge. Therefore, the influence of the discharge dv / dt can be intentionally separated from the control circuit which is likely to malfunction by separating the discharge portion from the control circuit by a certain distance.

  Further, the concentration of discharge is more likely to occur by removing the portion of the resist covering the normal pattern that contacts the edge of the metal case to expose the copper foil.

  Further, since the discharge-only pattern 8 is connected to the GND by the resistor 9, the dv / dt at the time of discharge is relaxed, and the GND connected for discharge is directly connected to the circuit power supply output, so that the control circuit Shaking due to discharge noise can be minimized, and malfunction and component destruction can be prevented.

  The electronic control device for an air conditioner according to the present invention can be applied to all devices that use a high-voltage power supply and that may be charged.

The block diagram of the electronic control apparatus of the air conditioner in embodiment of this invention Configuration diagram of electronic control device of air conditioner in the prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printed circuit board 2 Flame retardant resin case 3 Metal case 4 High voltage power supply 5 High voltage lead wire 6 Discharge electrode 7 Conductive pattern 8 Discharge exclusive pattern 9 Resistance 10 High voltage power supply 11 Relay part 12 GND pattern

Claims (1)

In an electronic control device configured to hold a printed board sandwiched between a case made of metal and a resin case, a part of the metal case is made to stand at an acute angle to make it easy to concentrate electric charges, and by a copper foil on the printed board A structure in which a copper foil is exposed by removing the resist at the contact portion of the pattern and contacting the configured discharge pattern, the discharge pattern is connected to a circuit ground pattern with a constant resistance, and the ground pattern Is an air conditioner that is directly connected to the output circuit ground of the power circuit.

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