JP4882479B2 - Power supply device and electric appliance having the same - Google Patents

Description

  The present invention relates to a power supply device in which a case in which a printed circuit board is stored is filled with a filler, and an electric appliance having the power supply device.

Conventionally, as a power supply device 1 for an electric appliance, as shown in FIG. 10, a case 7 containing a printed circuit board 5 is filled with a filler 8 made of epoxy resin, urethane resin, or the like so as to cover the printed circuit board 5. In this way, a component A mounted on the printed circuit board 5 with improved moisture resistance and vibration resistance is known. The case 7 has a box shape with an upper surface opening, and a lid 22 is covered on the opening surface. In the example of FIG. 10, ceramic balls 23 are spread between the bottom surface of the case 7 and the printed circuit board 5 to increase the heat radiation efficiency of the heat generating component A mounted on the printed circuit board 5 (see, for example, Patent Document 1). ).
JP-A-7-226465 (page 4, FIG. 1)

  By the way, in this kind of filler 8, what remained without reacting at the time of hardening of the filler 8 is ionized, the filler 8, the case 7, and the object to be filled (the printed circuit board 5 and the component A). There are many elements that corrode the conductor, such as those in which the impurities contained in the ionization are ionized and those in which the flame retardant added to the filler 8 is ionized to enhance the flame retardancy.

  Among these elements, those having a negative charge (hereinafter referred to as negative ions) move in the filler 8 by the Coulomb force generated between the printed circuit board 5 and a portion that generates a positive DC potential, Is attracted to a conductor that produces a direct current potential. When negative ions reach a conductor that generates a positive DC potential, the conductor is corroded (for example, oxidized, ionized, etc.), resulting in a decrease in conductivity. Note that some of the fillers 8 have a positive charge (hereinafter referred to as positive ions), but these positive ions will be described as an embodiment.

  Among the conductors that generate a positive DC potential, the soldered portion generally has a thickness of 100 to several hundreds of μm, so that the solder does not elute due to corrosion and does not break. On the other hand, the conductive part (pattern part) for forming a circuit pattern on the printed circuit board 5 is often several tens of μm thick, and the most common conductive part has a thickness of 18 μm. For this reason, the amount of the conductor (mainly copper) used for the conductive portion per unit area is small, and when the power supply device is used for a long time with negative ions collected in this conductive portion, the conductor is corroded. May be eluted and the conductive part may be disconnected. Moreover, the negative ions gathered at the conductive part that generates a positive DC potential may have a self-catalytic function for decomposing the nearby filler 8 due to its own acidity and generating negative ions. This will accelerate the corrosion of conductive parts.

  This invention is made | formed in view of the said reason, Comprising: It aims at providing the power supply device which can prevent the corrosion of an electroconductive part, and an electric appliance provided with the same.

In the first aspect of the present invention, a main power supply circuit that outputs a DC voltage, a control circuit that controls the operation of the main power supply circuit, and a control power supply circuit that supplies a DC voltage lower than that of the main power supply circuit to the control circuit are mounted. A power supply device provided with a printed circuit board in a box-like case and filled with a filler so as to cover the printed circuit board in the case, and the material of the filler is selected from urethane resin and epoxy resin The surface of the printed circuit board has a conductive part for forming a circuit pattern, a printed part for printing characters and symbols on the printed circuit board, and a direct current potential generated at the output end of the control power circuit among the conductive parts. also it provided a protective portion covering so as not to contact the packing material a conductive portion to produce a high DC potential, a protected site and the printing site is formed from a coating of the same material made of a synthetic resin Cage, the material of the coating is characterized by being selected from silicon resin and silicon rubber.

According to this configuration, the conductive portion that generates a DC potential higher than the DC potential generated at the output terminal of the control power supply circuit is protected by being covered with the protective portion made of synthetic resin so as not to contact the filler. Therefore, corrosion of the conductive part can be prevented. Moreover, since the protective part is formed of a coating made of the same material as the printed part on which characters and symbols are printed on the printed circuit board, the protective part can be formed simultaneously with the printed part at the time of manufacturing the printed circuit board. . Therefore, even when compared with a configuration in which a print site is provided without providing a protection site, the number of printed circuit board manufacturing steps does not increase. It should be noted that the characters and symbols printed at the print site include a component outline, a component symbol, a component constant, and the like. In addition, when all the conductive sites that generate a positive DC potential are covered with a protective site, negative ions that are present in the filler and have a negative charge are localized on the conductive site that generates the highest DC potential. There is a possibility that the performance of protecting the conductive part with respect to the protected part where the negative ions concentrate is deteriorated with time. On the other hand, when only a conductive part that generates a direct current potential higher than the direct current potential is covered with a protective part, negative ions are dispersed also in the conductive part not covered with the protective part, and the local concentration of negative ions Can be mitigated, so that the degradation of the protected site can be delayed.

Furthermore, according to this configuration, since a urethane resin or an epoxy resin is used as a material for the filler, the filler becomes inexpensive as compared with the case where a silicon resin is used as the filler. In addition, urethane resin and epoxy resin have an advantage that curing inhibition is less likely to occur than silicon resin.

Moreover, silicon resin and silicon rubber have a siloxane bond as a skeleton, and the siloxane bond is not easily degraded by decomposition. According to the above configuration, since the silicon resin or silicon rubber is used as the material of the film, the film is hardly deteriorated. In addition, there is an advantage that flux and solder scraps hardly adhere to the coating during soldering.

The invention of claim 2 is characterized in that, in the invention of claim 1, the material of the coating film contains a neutralizing agent that neutralizes negative ions.

  According to this configuration, since the neutralizing agent that neutralizes negative ions is included in the coating, the negative ions that have come into contact with the coating are neutralized by the neutralizing agent, and the protective site formed from this coating Corrosion due to negative ions of the conductive portion covered with can be reliably prevented.

The invention of claim 3 is characterized in that, in the invention of claim 1 or 2 , the difference between the output voltage of the main power supply circuit and the output voltage of the control power supply circuit is larger than 300V.

  According to this configuration, since the difference between the output voltage of the main power supply circuit and the output voltage of the control power supply circuit is larger than 300V, the output voltage of the main power supply circuit is a high value different from the output voltage of the control power supply circuit by 300V or more. Can be set to Here, if the output power of the main power supply circuit is constant, the output current decreases as the output voltage of the main power supply circuit increases. Therefore, by setting the output voltage of the main power supply circuit higher, the conductor used in the power supply device In addition, loss in the semiconductor element is reduced, and a highly efficient power supply device can be obtained.

According to a fourth aspect of the present invention, in any of the first to third aspects, a winding component having a magnetic member mounted on the printed board is provided, and the magnetic member of the winding component is the filler. The conductive portion that is in contact with the substrate and generates a DC potential is formed so as to avoid a portion that overlaps with the winding component in the thickness direction of the printed circuit board.

  According to this configuration, although the magnetic member of the winding component is in contact with the filler, the conductive portion that generates a direct current potential is formed avoiding the portion overlapping the winding component in the thickness direction of the printed circuit board. Therefore, it can be avoided that the temperature of the filler rises due to heat from the winding component and corrosion of the conductive portion is promoted.

The invention of claim 5 is characterized in that, in the invention of claim 4 , the filler is filled so as not to contact a winding portion of the winding component.

According to this configuration, since the filler does not come into contact with the winding part of the winding part, even if the dielectric constant of the filler is large, stray capacitance of the winding part is caused by the filler coming into contact with the winding part. And the inductance value of the winding component is not reduced. In addition, if the filler is in contact with the winding part, a dielectric loss occurs due to the voltage applied to the winding part, and the loss of the winding part increases and the temperature of the filler rises. However, according to the structure of Claim 5 , these malfunctions can also be avoided. Further, since the filler is less likely to receive heat from the winding portion, there is an effect that the temperature rise of the filler is suppressed.

The invention according to claim 6 is characterized in that the power source apparatus according to any one of claims 1 to 5 is provided in the instrument body.

  According to this configuration, the use of the power supply device in which the moisture resistance and vibration resistance of the components on the printed circuit board are increased by filling the filler, and the corrosion of the conductive portion is prevented by the configuration of claim 1. Can do. Accordingly, it is possible to provide a highly reliable electric appliance in which the power supply device is less likely to fail even during long-term use.

The invention of claim 7 is the invention of claim 6, an inverter circuit that outputs the connected high-frequency current to the main power circuit, an induction coil for receiving the output of the inverter circuit, becomes the discharge gas from the enclosed valve The instrument main body is provided with an electrodeless discharge lamp disposed in proximity to the induction coil.

  According to this configuration, the electrodeless discharge lamp has a long life, and in the power supply device, the configuration according to claim 1 prevents the corrosion of the conductive portion, and is less likely to fail even during long-term use. An electric appliance that does not require maintenance for a long time can be provided.

Since the present invention is protected by covering the conductive portion that generates a direct current potential higher than the direct current potential generated at the output terminal of the control power circuit with a protective portion made of synthetic resin so as not to contact the filler, Corrosion of the conductive part can be prevented. Moreover, since the protective part is formed of a coating made of the same material as the printed part on which characters and symbols are printed on the printed circuit board, the protective part can be formed simultaneously with the printed part at the time of manufacturing the printed circuit board. . Therefore, even when compared with a configuration in which a print site is provided without providing a protection site, the number of printed circuit board manufacturing steps does not increase. It should be noted that the characters and symbols printed at the print site include a component outline, a component symbol, a component constant, and the like. In addition, when all the conductive sites that generate a positive DC potential are covered with a protective site, negative ions that are present in the filler and have a negative charge are localized on the conductive site that generates the highest DC potential. There is a possibility that the performance of protecting the conductive part with respect to the protected part where the negative ions concentrate is deteriorated with time. On the other hand, when only a conductive part that generates a direct current potential higher than the direct current potential is covered with a protective part, negative ions are dispersed also in the conductive part not covered with the protective part, and the local concentration of negative ions Can be mitigated, so that the degradation of the protected site can be delayed.

(Embodiment 1)
As shown in FIG. 2, the power supply device 1 of the present embodiment includes a main power supply circuit 2 (see FIG. 6) that outputs a DC voltage Vm, and a control circuit 3 (see FIG. 6) that controls the operation of the main power supply circuit 2. And a printed circuit board 5 on which a control power supply circuit 4 (see FIG. 6) for applying a DC voltage Vs lower than that of the main power supply circuit 2 to the control circuit 3 is mounted. On the surface of the printed circuit board 5, conductive portions 6a to 6c for forming a circuit pattern are provided. Here, a double-sided printed board having conductive portions 6 a to 6 c provided on both sides in the thickness direction is used as the printed board 5. The power supply device 1 is configured by storing the printed circuit board 5 in a box-shaped case 7 and filling the case 7 with a synthetic resin filler 8 to a position where the printed circuit board 5 is immersed. The case 7 has an upper surface in FIG. 2 as an opening surface, and a lid (not shown) is covered on the opening surface. Note that a flame retardant is added to the filler 8 in order to improve flame retardancy.

  By the way, on the surface of the printed circuit board 5, there is provided a printing portion 9 a for printing characters and symbols on the printed circuit board 5, such as component outlines, component symbols, and component constants. The printed portion 9a is made from a synthetic resin film using a printing technique, and can be arbitrarily formed at a necessary position on the printed board 5 when designing the printed board 5. Further, the film forming the printing portion 9a has a thickness of 50 μm or more.

  In the present embodiment, as shown in FIG. 1, among the conductive portions 6 a to 6 c of the printed circuit board 5, the zero potential (0 V) is used as a reference potential, and the positive DC potential Vs at the output terminal of the control power supply circuit 4 is exceeded. A protective part 9b is provided at a position covering the conductive part 6a so that the conductive part 6a that generates a high DC potential does not contact the filler 8, and the filler 8 is filled from above the protective part 9b. The protection part 9b is formed from the same coating (made of synthetic resin) as the printing part 9a. That is, the protective site 9 b is interposed between the conductive site 6 a that generates a DC potential higher than the DC potential Vs at the output end of the control power supply circuit 4 and the filler 8. Here, the conductive part 6a which becomes the output end of the main power supply circuit 2 is covered with the protective part 9b.

  According to the above-described configuration, since the conductive portion 6a is protected by the protective portion 9b interposed between the conductive portion 6a and the filler 8, the corrosion of the conductive portion 6a can be prevented. In addition, the power supply device 1 with high reliability can be realized even when used for a long period of time.

  Moreover, the synthetic resin film forming the protective part 9b is conventionally provided on the printed circuit board 5 in order to form the printed part 9a on which characters and symbols are printed on the printed circuit board 5. And since it can be arbitrarily formed in the required part on the pudding board | substrate 5 by the printing technique as mentioned above, the protection part 9b which protects the electroconductive part 6a can be formed simultaneously with the printing part 9a. Therefore, the power supply device 1 according to the present embodiment does not increase the number of steps for manufacturing the printed circuit board 5 as compared with the configuration in which the print site 9a is provided without providing the protection site 9b, and as a result, the conductive site 6a. In order to prevent corrosion, it is possible to suppress an increase in cost due to the provision of the protection site 9b. Furthermore, since the coating film forming the printing part 9a and the protection part 9b has a thickness of 50 μm or more, it is a suitable material for protecting the conductive part 6a. About the power supply device 1 of this embodiment, the long-time operation test was performed by interposing the protection part 9b between the conductive part 6a (the output end of the main power supply circuit 2) that generates a high DC potential and the filler 8. However, it was confirmed that the corrosion of the conductive portion 6a was prevented. In the present embodiment, the conductive portion 6b that generates an alternating potential is not covered with the protective portion 9b.

  By the way, among the portions that generate a high DC potential, the soldered portion generally has a thickness of one hundred to several hundred μm, so that even if the solder corrodes, it does not reach the disconnection. On the other hand, among the portions that generate a high DC potential, the conductive portions (pattern portions) 6a to 6c that form a circuit pattern on the printed circuit board 5 are often several tens of μm thick, and the most common conductive portion 6a. The thickness of ˜6c is 18 μm. For this reason, there is little quantity of the conductor used for the electroconductive site | parts 6a-6c per unit area, and when this conductor corrodes, it may reach a disconnection. Therefore, in this embodiment, a configuration is adopted in which only the conductive portion 6a that generates a high DC potential is covered and protected by the protective portion 9b.

  Further, if all the conductive parts 6a to 6c that generate a positive DC potential are covered with the protective part 9b, the elements that corrode the conductive parts 6a to 6c have a negative charge (hereinafter referred to as negative charges). There is a possibility that the performance of protecting the conductive portions 6a to 6c with respect to the protection portion 9b where the negative ions are concentrated due to the concentration of the ions) (which are referred to as ions) at one place where the highest DC potential is concentrated. In the present embodiment, the conductive portion 6c that generates a low DC potential in the control circuit 3 or the control power supply circuit 4 does not have a strong attractive force with respect to negative ions and does not collect negative ions until disconnection occurs. In addition, since the negative ions are generally not concentrated at a specific location because they are wired finely and widely, the conductivity that generates a low DC potential (Vs or less) such as the output terminal of the control circuit 3 or the control power supply circuit 4. With respect to the part 6c, as shown in FIG. 3, negative ions are attracted to some extent without being covered with the protective part 9b. According to this configuration, concentration of negative ions on the conductive portion 6a (the output end of the main power supply circuit 2) that generates a higher DC potential Vm is suppressed, and deterioration of the protective portion 9b covering the conductive portion 6a is prevented. It was also found by an operation experiment.

  Here, a coating layer called a solder resist 10 is provided on the surface of the printed circuit board 5 to improve the moisture resistance of the printed circuit board 5 and prevent the accumulation of dust, thereby shortening the insulation distance defined by laws and regulations. . The protection part 9b and the printing part 9a are formed on the solder resist 10. However, the solder resist 10 originally prevents the solder from adhering to unnecessary portions, and is provided on almost the entire surface other than the portion to be soldered. Therefore, the solder resist 10 generates a high DC potential. Like the protection part 9b selectively provided in the conductive part 6a, the low DC potential in the control circuit 3 or the control power supply circuit 4 acts to collect negative ions, and the concentration of the negative ions in the conductive part 6a. There is no function to suppress this. If the solder resist 10 is provided only in the conductive portion 6a that generates a high DC potential Vm, such as the protection portion 9b of the present invention, a portion that is not covered with the solder resist 10 is formed on the printed circuit board 5. Since the moisture resistance of the substrate 5 and the performance of preventing dust accumulation are impaired, the insulation distance cannot be shortened and the printed circuit board 5 becomes large.

  In this embodiment, an organic polymer such as urethane resin or epoxy resin is used as the material for the filler 8. Thereby, compared with the case where other materials, such as a silicon resin (silicon resin), are used for the filler 8, there exists an advantage by which the filler 8 becomes cheap. In addition, there are few problems such as inhibition of curing, and the filler 8 can be filled even in the power supply device 1 having a structure that cannot be filled with the filler 8 such as silicon resin due to inhibition of curing. The filling of the filler 8 facilitates the heat dissipation design by improving the heat dissipation, and the waterproofness and moisture resistance of the power supply device 1 are improved, so that the power supply device 1 itself and the electric appliance equipped with the power supply device 1 can be improved. The structure for waterproofing and moisture resistance can be simplified. Furthermore, since there are few problems such as curing inhibition, the selection range of parts is broadened and the management of the manufacturing process is facilitated, so that it is possible to realize the power supply device 1 that is less expensive and highly reliable.

  However, when a urethane resin or an epoxy resin is used as the material of the filler 8, hydrolysis may occur if the filler 8 itself is placed in a high temperature / high humidity environment. Therefore, for example, when a urethane resin is used, in addition to the element that corrodes the conductor originally present in the filler 8, any bond between the ester bond and the urethane bond is cut, so that acid, negative Generates ions. Acids and negative ions generated by hydrolysis also cause corrosion (oxidation and ionization) of the conductive portion 6a, but the protective portion 9b is interposed between the filler 8 and the conductive portion 6a as in this embodiment. According to the structure in which is interposed, corrosion of the conductive portion 6a can be prevented.

  Further, in order to enhance the effect of protecting the conductive portion 6a in the protection portion 9b, a neutralizing agent that neutralizes negative ions is added to the material of the film that forms the protection portion 9b and the printing portion 9a. Thereby, when the negative ions in the filler 8 are attracted to the conductive portion 6a having a high DC potential, the negative ions are neutralized with the neutralizing agent before reaching the conductive portion 6a, and the protective portion 9b. And corrosion of the conductive portion 6a can be suppressed. Moreover, since a neutralizing agent should just be added only to the site | part where a negative ion collects, a big effect is acquired with a small amount of neutralizing agent.

  An example of this neutralizer is a carbodiimide compound. In particular, when the filler 8 is a urethane resin, the carbodiimide compound not only neutralizes the negative ions and hydrolysis in the filler 8, but also neutralizes the negative ions, the acid generated by hydrolysis, The negative ions further have an effect of preventing the autocatalytic action of decomposing the filler 8 (urethane resin).

  Further, silicon resin or silicon rubber may be used as the material of the filler 8.

  Conventionally, positive ions that are present in the filler 8 and have a positive charge accumulate in a portion that produces a relatively negative DC potential, creating a tree-like conductive portion, and deteriorating insulation performance. Widely known as migration. Since this migration occurs at a location where a negative DC potential is generated relative to positive ions, the migration is zero on the printed circuit board 5 mounted with the main power supply circuit 1 that generates a positive DC potential with the zero potential as a reference potential. Occurs on the potential side. The zero potential is widely used as a reference potential for circuit operation, a feedback route of operation current, a shield against noise, and the like, and is distributed over a wide range on the printed circuit board 5. For this reason, positive ions that cause migration are dispersed over a wide range, and it takes a long time until problems such as deterioration of insulation performance occur. Therefore, the configuration for preventing such migration due to positive ions is different from the present invention for preventing the corrosion of the conductive portion 6a.

  In addition, the conductive part created by migration disappears when it generates heat when a small amount of current flows, so this is used to design a large amount of current to flow in a location where migration is likely to occur. It is possible. As a result, the influence of the reduced current due to the insulation deterioration can be made difficult, or the conductive portion caused by the migration can be eliminated by the reduced current. On the other hand, the subject of the present invention is to prevent the corrosion of the conductive portion 6a, and it is impossible to use means such as disappearance of a defective portion due to an electric current used for protection against migration.

(Embodiment 2)
As shown in FIG. 4, the power supply device 1 of the present embodiment is different from the first embodiment in that a winding component 12 having a magnetic member 11 is mounted on a printed board 5.

  In the present embodiment, the magnetic member 11 of the winding component 12 is brought into contact with the filler 8. For this reason, the heat generated in the winding component 12 is transmitted to the filler 8, the temperature of the filler 8 rises, the amount of acid and negative ions generated in the filler 8 increases, and the mobility of acid and negative ions. Or the like, the acid and negative ions are likely to concentrate on the conductive portion 6a that generates a high DC potential, and the conductive portion 6a may be easily corroded. Therefore, as shown in FIG. 5, a DC potential is applied to a portion overlapping the winding component 12 in the thickness direction of the printed circuit board 5, that is, on the projection surface of the winding component 12 on the printed circuit board 5 and the back surface of the projection surface. The conductive portions 6a and 6c that cause the problem are not provided. As a result, the conductive portion 6a does not exist in the portion immediately below the winding component 12 that is easily affected by the heat from the winding component 12 in the printed circuit board 5. Therefore, the conductive portion is caused by the temperature rise of the filler 8 as described above. It can avoid that 6a becomes easy to corrode.

  In addition, when a silicon resin is used for the material of the filler 8, it is possible to suppress the temperature rise when the winding component 12 is energized by dissipating heat generated in the winding component 12 to the filler 8. . As a result, the winding component 12 can be reduced in size and extended in life, and the reliability of the winding component 12 can be improved.

  In addition, since the filler 8 generally has a dielectric constant higher than that of air, high-frequency electrical components that cause electromagnetic noise are easily transmitted through the filler 8. For this reason, in the power supply device 1 using the filler 8, the components on the printed circuit board 5 (the winding component 12, the film capacitors C1 to C3, the semiconductor elements S1 and S2 in FIG. 5) and the conductive portions 6a to 6c ( The high-frequency electrical component of the pattern portion) propagates to the other conductive portions 6a to 6c through the filler 8 and easily causes malfunction. In particular, since the high-frequency magnetic field is generated in the winding component 12 through which a high-frequency current flows, it is likely to be a source of electromagnetic noise. In order to cope with this type of electromagnetic noise, it is necessary to provide a filter circuit or the like. Here, in the present embodiment, since the conductive portions 6a to 6c are not arranged immediately below the winding component 12 on the printed circuit board 5 where electromagnetic noise is particularly large, malfunction due to electromagnetic noise is unlikely to occur, and the filter circuit is small. There is an advantage that it can be reduced or omitted.

  Further, in the present embodiment, the material of the coating film that forms the protection site 9b and the printing site 9a is selected from silicon resin and silicon rubber. Silicon resin and silicon rubber have a siloxane bond as a skeleton.

  The protective part 9b is required to have a function of protecting the conductive part 6a. However, if the protective part 9b itself deteriorates, the protective part 9b is peeled off or a gap is formed to protect the conductive part 6a. It may not be possible. It is known that siloxane bonds are not easily degraded by decomposition. In other words, when silicon resin or silicon rubber is used as the material for the coating, the durability of the protective portion 9b is improved without causing any problems in the printing of the component constants and component symbols, which are the original purposes of the printing portion 9a. Thus, the conductive portion 6a can be reliably protected.

  In addition, when flux or solder scraps adheres to the protection site 9b or the printing site 9a during soldering, the insulation performance of the printed circuit board 5 decreases, and when a highly reactive flux adheres, the filler 8 is cured when the filler 8 is cured. There is a risk of causing poor curing. Here, when silicon resin or silicon rubber is used as the material for the coating, there is also an effect of reducing adhesion of flux and solder scraps during soldering.

  Other configurations and functions are the same as those of the first embodiment.

(Embodiment 3)
In the present embodiment, as shown in FIG. 6, an electric appliance provided with the power supply device 1 described in the second embodiment in the appliance main body 13 is illustrated. Specifically, an inverter circuit 14 that is connected to the main power supply circuit 2 and outputs a high-frequency current, an induction coil 15 that receives the output of the inverter circuit 14, and a metal vapor and an inert gas that are arranged near the induction coil 15 And an electrodeless discharge lamp 16 composed of a bulb in which a discharge gas (for example, mercury and a rare gas) that is a mixed gas is provided in the fixture body, and the electrodeless discharge lamp 16 is turned on by power supply from the power supply device 1 The appliance is shown as an electrical appliance. The control circuit 3 also has a function of controlling the operation of the inverter circuit 14.

  By the way, as described in the first embodiment, negative ions also collect in the positive DC potential Vs output from the control power supply circuit 4. However, the negative ions collect at the output terminal of the control power supply circuit 4 is higher DC current. Thus, the conductive portion 6a which is the output end of the main power supply circuit 2 that generates the failure is protected. For this reason, the larger the potential difference V between the DC potential Vs generated at the output terminal of the control power circuit 4 and the DC potential Vm generated at the output terminal of the main power circuit 2, the more negative ions collected on the DC potential Vm on the main power circuit 2 side. The proportion of increases. Therefore, in the conventional power supply device 1 in which the conductive part 6a serving as the output end of the main power supply circuit 2 is not covered with the protective part 9b, the corrosion of the conductive part 6a proceeds faster as the potential difference V increases. The time T until the malfunction of the operation of the power supply device 1 due to the corrosion of the conductive portion 6a is expressed by an exponential function of the potential difference V as shown in the following equation. In the following formula, a represents a relative value constant.

T = aV ^ (-n)
In the above equation, n is a constant determined by the material of the conductive portion 6a, the material of the printed circuit board 5, and the like, and has a value of about 0.3 to 0.7. FIG. 7 shows the relationship between the potential difference V and the time T when a = 10 and n = 0.4 in the above equation, where the horizontal axis is the potential difference V and the vertical axis is the time T until failure occurs.

  That is, even in the conventional power supply device 1 in which the conductive portion 6a is not covered with the protective portion 9b, when the potential difference V takes a low value of 100 to 200V as shown in FIG. It is possible to greatly increase the time T until the occurrence of a failure by making a slight adjustment by design. However, when the potential difference V is 300 V or more, the time T until the failure occurs hardly changes. Therefore, it is difficult to increase the time T until the failure occurs only by adjusting the potential difference T.

  Furthermore, if the output power of the main power supply circuit 2 is constant, the higher the output voltage Vm of the main power supply circuit 2 is, the smaller the output current is and the loss in the conductors and semiconductor elements used in the power supply device 1 is reduced. A highly efficient power supply device 1 can be obtained. Therefore, in the conventional power supply device 1 in which the conductive portion 6a is not covered with the protective portion 9b, it is desirable to set the output voltage Vm of the main power supply circuit 2 as high as possible within a range where the potential difference V does not exceed 300V. However, the higher the DC potential Vm generated at the conductive portion 6a, the greater the attractive force for collecting negative ions. Therefore, in the conventional power supply apparatus in which the conductive portion 6a is not covered with the protective portion 9b, the conductive portion 6a There is a problem that the higher the DC potential Vm generated, the more easily the conductive portion 6a corrodes. In the conventional power supply device 1, the time T until the occurrence of a failure decreases exponentially as the output voltage Vm of the main power supply circuit 2 increases.

  On the other hand, since the power supply device 1 of the present embodiment covers the conductive portion 6a serving as the output end of the main power supply circuit 2 with the protective portion 9b, corrosion of the conductive portion 6a is prevented. Even in the case where there is the above potential difference V, it is possible to lengthen the time T until the occurrence of a failure. Even if the output voltage Vm of the main power supply circuit 2 is high, the conductive portion 6a is not corroded. Therefore, in this embodiment, by setting the output voltage Vm of the main power supply circuit 2 high so that the potential difference V is larger than 300 V, loss in the conductors and semiconductor elements used in the power supply device 1 is reduced. A highly efficient power supply device 1 is realized.

  Further, in the present embodiment, as shown in FIG. 8, a diffusion plate 17 that is disposed so as to surround the electrodeless discharge lamp 16 and diffuses light from the electrodeless discharge lamp 16 is provided, and outside the diffusion plate 17. By providing a glove 18 and an umbrella 19 for sealing the electrodeless discharge lamp 16 together with the case 7 in which the power supply device 1 is housed, an outdoor electric appliance having waterproofness and moisture resistance is configured. The globe 18 is made of transparent glass or plastic so as to transmit light from the electrodeless discharge lamp 16. A heat radiating plate 20 is provided between the electrodeless discharge lamp 16 and the case 7. In this type of outdoor electric appliance, rainwater enters the electric appliance due to corrosion of the metal material, damage to the globe 18 or the umbrella 19 during the period of use of the electric appliance, or the humidity in the electric appliance is low. It is common to fill the case 7 with a filler 8 so that it can be used even when it is raised.

  On the other hand, the electrodeless discharge lamp 16 has a feature that it has a longer life than other lamps for illumination. The electrodeless discharge lamp 16 that is generally provided has a lifespan of 60000 hours, and the electrodeless discharge lamp 16 does not need to be replaced in principle for about 16 years even if it is turned on for 10 hours per day. For this reason, in an electric appliance having an illumination lamp with a life of about 10,000 hours as a load, for example, maintenance such as an appearance inspection of the power supply device 1 is often performed when the lamp is replaced every 10,000 hours, for example. In the present embodiment in which the electrodeless discharge lamp 16 is used as a load, lamp replacement is hardly performed, so that maintenance such as appearance inspection of the power supply device 1 is often not performed. In particular, this type of electric appliance is often installed in places where it is difficult to perform maintenance such as road lights, street lights and high ceiling lights, taking advantage of the long-life characteristics of the electrodeless discharge lamp 16, so maintenance is even more so. Is often not done. For this reason, when the electrodeless discharge lamp 16 is used for the load of the power supply device 1, the power supply device 1 is required to have high reliability over a longer period.

  Here, since the power supply device 1 used in this embodiment can prevent the corrosion of the conductive portion 6a, the power supply device 1 breaks down due to the corrosion of the conductive portion 6a before the life of the electrodeless discharge lamp 16 expires. The problem can be avoided, and it is suitable for an electric appliance for outdoor use and having the electrodeless discharge lamp 16 as a load.

  By the way, since the dielectric constant of the filler 8 is larger than the dielectric constant of air, when the filler 8 adheres to the winding portion 21 of the winding component 12, the stray capacitance of the winding component 12 increases and the winding component 12. By lowering the inductance value, the operation may be different from the original design. When this winding component 12 is used as an electromagnetic noise countermeasure filter, the electromagnetic noise passes through the stray capacitance, the amount of electromagnetic noise generated in the power supply device 1 increases, or the winding component corresponds to the increased electromagnetic noise. It may be necessary to enlarge 12. Therefore, in this embodiment, as shown in FIG. 9, the filler 8 is in contact with the magnetic member 11 of the winding component 12 while the filler 8 is in contact with the winding portion 21 as shown in FIG. 9. It is set not to touch. Furthermore, in this configuration, the filler 8 is less likely to receive heat from the winding portion 21, so that an increase in the temperature of the filler 8 is also suppressed.

  An electric appliance having the electrodeless discharge lamp 16 as a load causes a high frequency electromagnetic field to act on the discharge gas in the electrodeless discharge lamp 16 by the induction coil 15 to light the electrodeless discharge lamp 16, and thus becomes an electromagnetic noise generation source. Although easy, this embodiment has an advantage that it can easily cope with the generation of electromagnetic noise as described above.

  Further, if the winding portion 21 is in contact with the filler 8, dielectric loss occurs due to the voltage applied to the winding component 12. Therefore, the loss of the winding component 12 increases due to the dielectric loss, and the power supply device 1. In addition to a decrease in efficiency, the temperature of the filler 8 rises and the conductive portion 6a tends to corrode as described above. These problems can also be avoided by arranging them so as not to contact with each other.

  Other configurations and functions are the same as those in the second embodiment.

It is sectional drawing which shows the principal part of Embodiment 1 of this invention. It is sectional drawing which shows a structure same as the above. It is sectional drawing which shows the principal part same as the above. It is sectional drawing which shows the structure of Embodiment 2 of this invention. It is a top view which shows the printed circuit board used for the same as the above. It is a block diagram which shows the structure of Embodiment 3 of this invention. It is a graph which shows the relationship between an electric potential difference and malfunction occurrence time. It is sectional drawing which shows the structure of the electric appliance same as the above. It is sectional drawing which shows a structure same as the above. It is sectional drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power supply device 2 Main power supply circuit 3 Control circuit 4 Control power supply circuit 5 Printed circuit board 7 Case 8 Filler 11 Magnetic body member 12 Winding component 13 Instrument main body 14 Inverter circuit 15 Induction coil 16 Electrode discharge lamp 21 Winding part 6a- 6c Conductive part 9a Print part 9b Protective part

Claims (7)

A box-shaped case having a printed circuit board on which a main power circuit that outputs a DC voltage, a control circuit that controls the operation of the main power circuit, and a control power circuit that supplies a DC voltage lower than the main power circuit to the control circuit are mounted. A power supply device provided with a filler filled in a form covering the printed circuit board in the case,
The material of the filler is selected from urethane resin and epoxy resin,
On the surface of the printed circuit board, the conductive part forming the circuit pattern, the printed part where characters and symbols are printed on the printed circuit board, and the direct current potential generated at the output end of the control power circuit among the conductive part And a protective part that covers the conductive part that generates a high direct current potential so as not to contact the filler,
The power supply device , wherein the printing part and the protection part are made of a synthetic resin film made of the same material , and the material of the film is selected from silicon resin and silicon rubber . The power supply apparatus according to claim 1 , wherein the material of the coating includes a neutralizing agent that neutralizes negative ions . The power supply device according to claim 1 or 2 , wherein a difference between an output voltage of the main power supply circuit and an output voltage of the control power supply circuit is larger than 300V . A winding component having a magnetic member mounted on the printed board is provided, the magnetic member of the winding component is in contact with the filler, and the conductive portion that generates a DC potential is in the thickness direction of the printed board 4. The power supply device according to claim 1, wherein the power supply device is formed so as to avoid a portion overlapping with the winding component . The power supply device according to claim 4 , wherein the filler is filled so as not to contact a winding portion of the winding component . Electrical device with a to that power supplies comprising: a power supply device according to the instrument body in any one of claims 1 to 5. An inverter circuit that is connected to the main power supply circuit and outputs a high-frequency current; an induction coil that receives the output of the inverter circuit; and an electrodeless discharge lamp that is a valve that contains a discharge gas and is disposed in proximity to the induction coil. The electric appliance provided with the power supply device according to claim 6, wherein the electric appliance is provided in a main body .

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