JPS61150670A - Control device for plating rectifier - 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 Application of the Invention] The present invention relates to a control device for a plating rectifier, and is particularly applicable to a plating process in which objects to be plated with different plating currents are introduced into each of a plurality of electrolytic baths. The present invention relates to a control device for a plating rectifier that facilitates fine adjustment.

[Background of the invention]

FIG. 1 is a block diagram showing a conventional control device for a plating rectifier. Each output terminal of rectifiers 12A to 12E is connected to the object to be plated that is introduced into each of electrolytic baths 10A to 10E. Each of the rectifiers 12A to 12E includes an analog memory 14A to 14E for setting the rectifier output current.
are connected, and write signals 16A to 16 are connected to each of these.
A control unit 18 for providing E is connected. In addition, a digital switch 20A is used to set the current value in four stages.
20D are provided, and their respective outputs are selectively output by switches 24A to 24D driven by switch selection signals 22A to 22D output from the control section 18.

Each of the switches 24A to 24D has a digital-to-analog (D/A) signal for converting the digital signal output from each of the digital switches 20A to 20D into an analog signal.
A) Each of converters 26A-26D is connected. D
The outputs of the /A converters 26A-26D are commonly connected and applied to each of the analog memories 14A-14E.

In the above configuration, digital switches 2OA and 20B
, 20G, 20D are, for example, 160A, 170
A, 180A, and 190A (current values are set to
Any one of A to 24D is selected. The digital signal of the selected digital switch 24A is converted into an analog signal by the D/A converter 26A connected to the selected switch 24A, and a write signal 16A is generated.
The signal is applied to any of the analog memories 14A to 14E specified by 16E, and the switch number is stored. During plating, the object to be plated is transferred from the pretreatment tank to each of the plating tanks 10A to IOE by a conveyor or the like, and the switch selection signals 22A to 22D and the write signal 1 are input into the tanks.
6A to 16E are synchronized, a desired plating current value can be set for the rectifier connected to the electrolyte introduced for each object to be plated, and optimal plating can be performed.

However, in the conventional plating rectifier control device,
Since the current value is set digitally, there is a problem that fine adjustments cannot be made for deviations in the setting signal. Furthermore, since the selection of the digital switch is performed using relay contacts, the lifespan and reliability are poor.

[Purpose of the invention]

The present invention has been made in view of these circumstances, and therefore proposes a control device for a plating rectifier that is capable of performing giA adjustment of current value setting and electronically switching the signal system. The purpose is to

[Summary of the invention]

The present invention uses a plurality of potentiometers as a current setting device, selects a potentiometer set to a desired current value by an analog multiplexer connected to each of the rectifiers, and uses the output of the selected potentiometer as the current setting value. This is how it was done.

〔Example〕

Hereinafter, preferred embodiments of a control device for a plating rectifier according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a block diagram showing one embodiment of the present invention. In FIG. 2, the same reference numerals are used for parts that are the same as those in FIG. 1 or have the same functions.

Potentiometers 32A to 32 are connected to the DC power line 30.
D is connected. 4 of potentiometers 32A to 32D
Each of the book's output lines has an analog multiplexer 34A that selects one of the lines as an input line.
~34E are connected in parallel. The potentiometers 34A to 34E are controlled by a write signal 36A and an analog selection signal 38 output from the control unit 18,
Select the input line (ie, current value).

FIG. 3 shows the detailed configuration of analog multiplexers 34A to 34E, and potentiometers 32A (CHl) to 32
D Set the number of channels of (CH4) to 3 bits (AO, Al, A2
), a latch circuit 34a that latches the analog selection signal 38 from the control unit 18, a decoder 34b that decodes the output signal of the latch circuit 34a and outputs a drive signal,
A driver 34c turns on and off the electronic switch 34d according to a drive signal output from the decoder 34b, and one of them is turned on by the driver 34c and the CH
Each of the electronic switches 34d connects one of the O-CH7 to the output terminal 40.

In the above configuration, if the potentiometer 11A is selected for the first object to be plated that is introduced into the electrolytic bath 10A, the control section 18 controls the analog multiplexer 3.
A2 and A1 of the analog selection signal 38 for 4A
set to lol+ and set AO to “l”. As a result, the decoder 34b selects CHI, and the driver 34c turns on the switch 34d corresponding to CHI.
A CHI analog signal is output to the output terminal 40.

This analog signal is output to the rectifier 12A, and a write signal 36 is applied to the analog multiplexer 34A, and the CHI selection number is held in the latch circuit 34a. Similarly, for multiplexers 34B to 34E,
An analog selection signal 38 is applied in accordance with the current value required by each of the objects to be plated introduced into the electrolytic structures 10B-10, and one of the output signals of the potentiometers 32A-32D is selected.

The analog selection signal 38 is selected as follows depending on the number of CHs (channels) of the potentiometer. If it is desired to further increase the number of channels, the number of inputs may be increased in addition to AO-A2. For example, by using AO-A3 with four people, it is possible to select 16 channels and finely adjust the current setting value.

〔Effect of the invention〕

As explained above, according to the control device for a plating rectifier according to the present invention, a plurality of analog current setting values are selected by the multiplexer connected to each of the rectifiers. An arbitrary current setting value can be obtained with a simple configuration in just a few minutes, and fine adjustment is easily possible.

Furthermore, since the current setting value is switched purely electronically without using mechanical contacts, it is possible to extend the life of the device and improve reliability.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional control device for a plating rectifier, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a detailed block diagram of an analog multiplexer according to the present invention. 10A~IOE... Electrolyte, 12A~12E...
Rectifier, 18...control unit, 32A to 32D...
Potentiometer, 34A to 34E...Analog multiplexer, 34a...Latch circuit, 3
4b...decoder, 34c...driver, 3
4d...Sui Nochi. Applicant Hitachi Plant Construction Co., Ltd. Figure 1 Figure 2 1n Figure 3

Claims (1)

[Claims] In a control device for setting a plating current for a plurality of rectifiers connected to each of a plurality of electrolytic vessels and supplying a plating current corresponding to a set value, a plurality of potentiometers each having a desired current value set therein; a plurality of analog multiplexers that are connected to each of the rectifiers, take the output of each of the potentiometers as input, select one of these and output it to the corresponding rectifier; and the potentiometer that outputs a desired current value. A control device for a plating rectifier, comprising: a control section that sends a command for selection to each of the plurality of multiplexers.