JP4704590B2 - Plating current supply power supply - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of a power supply apparatus in which a resistor is connected between load terminals of a DC power supply for plating noble metal to stabilize output control.
[0002]
[Prior art]
FIG. 5 shows a circuit configuration diagram of a conventional plating current supply power supply device. In FIG. 5, the plating metal 2 is connected to the positive output terminal 11 of the DC power source 1, and the object to be plated 3 is connected to the negative output terminal 12. The plating object I is plated by flowing a plating current I from the plating metal 2 to the object to be plated 3 through the plating bath 5 filled in the plating tank 4. The plating load includes a plating bath 5 in the plating tank 4, a plating metal 2, and an object 3 to be plated. When the plating metal is a noble metal plating such as gold, silver or platinum, the management of the plating current is important, and the DC power source 1 has a constant current control function. When contact failure occurs on the load side and energization becomes difficult, the current is forced to flow to maintain a constant current value, so the DC output voltage increases. At that moment, if the current is temporarily energized, the voltage immediately decreases, and if the voltage decreases, the contact failure is reproduced and the load current becomes zero, so the DC output voltage increases. Such a load side cause the current and voltage to become negatively stable and become uncontrollable.
[0003]
In order to prevent such a trouble from occurring, the DC power source 1 needs to always allow a small amount of current to flow from the output terminals 11 and 12, and this current is referred to as a bleeder current. In order to flow the bleeder current, the bleeder resistor R is connected to the intermediate point between the output terminal and the plating load. In this way, output control has been stabilized. In the case of noble metal plating, when the DC power supply 1 is turned off, a current flows from the substrate 3 to the plating bath, plating metal, connection point 13, bleeder resistance R, and connection point 14 (this is referred to as a dissolution current). It was found that the plating quality was deteriorated due to the phenomenon that the plated metal was dissolved on the object to be plated.
[0004]
[Problems to be solved by the invention]
As described above, it is an object of the present invention to provide a plating current supply device with an output control function that prevents the plated metal of the object to be melted when the output of the DC power supply is OFF.
[0005]
[Means for Solving the Problems]
In the present invention, attention has been paid to preventing the dissolution current that causes the plated metal from dissolving. In a plating current supply power supply apparatus in which a plating metal is connected to a positive output terminal of a DC power source equipped with an output ON command switch and an output OFF command switch, and an object to be plated is connected to a negative output terminal. In order for the bleeder current to flow only when the bleeder resistor is connected via the switching means and the output ON is commanded, the operation of the switching means is closed in conjunction with the output ON command switch of the DC power supply. The contact is opened in conjunction with the output OFF command switch of the DC power supply, and the bleeder current is disconnected to prevent the bleeder current from flowing.
[0006]
With respect to claim 2, in the case where the switching means for energizing and interrupting the bleeder current is a contact type, contact failure of the contact and contact welding that is likely to occur with direct current may cause unsafe accidents. It was set as the non-contact switching means comprised by these. A signal generator for generating a signal to be supplied to the semiconductor switching element in conjunction with a DC power ON / OFF command is connected.
[0007]
According to a third aspect of the present invention, there is provided a bleeder resistance between the output terminals in a plating current supply power supply apparatus in which a plating metal is connected to a positive output terminal of a DC power source and an object to be plated is connected to a negative output terminal. And a diode or other element that conducts in only one direction is plated at an intermediate point between the connection point of the bleeder resistor and the plated metal, or an intermediate point between the other connection point of the bleeder resistor and the object to be plated. By interposing in the same direction as the direction of current flow, the current in the direction opposite to the plating current is blocked, so that no melt current flows from the object to be plated to the bleeder resistance.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIG. AC is an AC input terminal, a DC power supply 1 is connected between the terminals, output terminals 11 and 12 are connected to the plating metal 2 and the object 3 to be plated, respectively, and the plating current I is energized in the direction of the solid arrow. . In the plating bath 5 filled in the plating tank 4, the plating metal 2 is ionized by the above energization, moves through the plating bath, adheres to the surface of the object to be plated, and is plated. . The bleeder resistance R is connected between the output terminals via the opening / closing means 33 in order to eliminate the disadvantage that the plating metal on the surface of the object to be melted when the current i in the direction opposite to the plating current I indicated by the solid line arrow flows. The connection points are 13 and 14.
[0009]
The switching means 33 connected to the bleeder resistor R uses a set of contacts among the switching contacts 31, 32, 33 that are attracted and closed by the coil 30 of the AC relay connected to the AC input terminal AC of the DC power supply 1. . Since the coil 30 is energized by the ON operation of the output ON command switch 20 of the DC power supply 1, the waste contact 33 is also closed in conjunction with the closing of the switching contacts 31 and 32, and the bleeder resistor R is connected. In the case of a device with a rated output of the DC power supply 1 of 5 V and 100 A class, the bleeder resistor R is selected so that a bleeder current of about 0.1 A flows. The switching contact 31 connects an AC commercial power source to the DC power source 1, and the DC power source 1 converts AC to DC and supplies current to the plating load. The switching contact 32 self-holds the energized state of the coil 30.
[0010]
By operating the output OFF command switch 25 of the DC power supply 1, the current of the coil 30 is turned OFF, and all the contacts 31, 32, 33 are opened. In this state, the operation of the output ON command switch is awaited, but the plating current I is cut off and the plating is stopped. The switching contact 33 cuts off the melting current i in the direction opposite to the plating current from flowing through the bleeder resistance as indicated by the dotted arrow, so that the bleeder resistance is disconnected from the circuit. Since the dissolution current i does not flow when the output of the DC power supply 1 is OFF, the plating quality is prevented from being dissolved from the object to be plated, thereby avoiding deterioration of the plating quality.
[0011]
With respect to claim 2, as shown in FIG. 2, the switching means 34 connected to the bleeder resistor R is a contactless switching means formed of a semiconductor switching element. The switching means 34 is contactlessly opened and closed so as to be turned ON / OFF in response to a signal from the signal generator S connected to the input side of the DC power supply 1, so that the bleeder is interlocked with the ON / OFF command switch of the DC power supply 1. Connect or disconnect a resistor. By making the switching means non-contact, it is possible to avoid contact failure troubles that are likely to occur when using at low voltage.
[0012]
With respect to claim 3, as shown in FIGS. 3 and 4, a diode D1 or D2 is connected between the connection points 13 and 14 of the bleeder resistor R connected to the output side of the DC power source 1 and the plating load, and the plating load is obtained. Thus, the melting current that tends to flow in the direction of the bleeder resistance R is blocked, and the current flows only in the direction of the plating current I. In FIG. 3, a diode D1 is connected between the positive output side bleeder resistance connection point 13 and the plating metal 2 with a polarity matching the plating current direction. In FIG. 4, a diode D2 is connected between the negative output side bleeder resistance connection point 14 and the workpiece 5 with a polarity matching the plating current direction. In both cases of FIG. 3 and FIG. 4, the bleeder resistor R acts so that the reverse current of the plating current does not flow from the plating load when the DC output is OFF, and plating when the DC output is ON. When the current flows, the current also flows through the bleeder resistor. Therefore, when formed as a simple chassis power supply unit that does not incorporate a command switch, the chassis operation surface is simplified and the manufacturing is easy and economical. There is an advantage that the configuration of the apparatus is advantageous.
[0013]
【The invention's effect】
As described above, the bleeder resistor, which is always connected in parallel with the load, is connected and disconnected in conjunction with the output ON / OFF operation switch so that the control of the output voltage and current does not become unstable. By preventing the reverse current of the plating current by interposing means for conducting the current only in one direction, it was possible to prevent the precious metal plated on the object to be melted. For this reason, a current supply device has been realized that can prevent plating quality defects of precious metal plating. It contributes to resource saving by eliminating the waste of precious metals and has great industrial value.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a circuit configuration showing an embodiment of the present invention.
FIG. 2 is a circuit configuration explanatory view showing another embodiment of the present invention.
FIG. 3 is an explanatory diagram of a circuit configuration showing another embodiment of the present invention.
FIG. 4 is a circuit configuration explanatory view showing another embodiment of the present invention.
FIG. 5 is a circuit configuration diagram of a conventional device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 DC power supply 2 Plating metal 3 To-be-plated object 4 Plating tank 5 Plating bath AC AC input terminal I Plating current i Melting current R Bleeder resistance S Signal generator D1 Diode D2 Diode 11 Positive output terminal 12 Negative output terminal 13 Bleeder resistance Connection point 14 Bleeder resistance connection point 20 Output ON command switch 25 Output OFF command switch 30 AC relay coil 31 Open / close contact 32 Open / close contact 33 Open / close means (open / close contact)
34 Non-contact switching means (semiconductor switching element)

Claims (2)

A DC power source that converts the input from the AC input terminal to DC and outputs the output ; an output ON command switch; and an output OFF command switch. The plated metal is on the positive output terminal of the DC power source and the negative output terminal is on the negative output terminal. In the plating current supply power supply device to which the objects to be plated are connected ,
A bleeder resistor connected between the output terminals;
Opening / closing means connected to the bleeder resistor;
A switching contact connected between the AC input terminal and the DC power source,
The switching means and the switching contact are closed in conjunction with the output ON command switch,
A plating current supply power supply device that opens in conjunction with the output OFF command switch.  2. The plating current supply power source device according to claim 1, wherein the switching means is a contactless switching means composed of a semiconductor switching element.

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