JPH06114375A - Overcurrent protecting device in ion water maker - Google Patents

Abstract

PURPOSE:To provide a simplified overcurrent-protective circuit without heat generation for an ion water maker to effect fold-back current limiting control by software means. CONSTITUTION:The ripple component of an electrolytic current is detected by the comparator of a current detection block 2 and sent to a control part as the input of a current value. The control part 3 judges an overcurrent from the duty ratio of the input of the current value to send out voltage setting output for protecting an overcurrent due to the fold-back current limiting characteristics. In a voltage setting block 4, the turn ON-time of the SCR of a rectifier circuit is controlled corresponding to the voltage setting output to control electrolytic output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overcurrent protection device for detecting and protecting an overcurrent flowing in an electrolytic cell of an ion water generator.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram of a conventional ion generator. An electrolytic power source V ₀ is applied to the electrodes 105 and 106 of the electrolytic cell 104 via the rectifier circuit 100 and the regulator 101 to electrolyze and generate ionized water. When the overcurrent I ₀ flows during electrolysis, the overcurrent I ₀ (for example, 2.5 A or more) flowing through the current detection resistor 103 connected in series is detected for the purpose of protecting the electrolytic cell 104.

The detection of the overcurrent I ₀ is performed by turning on / off the transistor by the voltage across the current detection resistor 103. By turning on the transistor, the O of the power FET is turned off.
The electrolytic switch 109 is turned off by N / OFF to turn off the electrolytic power source to cut the electrolytic current.

When the electrolytic current value is normal, the electrolysis of the raw water flowing into the electrolytic cell 104 is continued, and the alkaline ionized water having a high pH and the acidic water having a low pH are separated and produced. For alkaline ionized water, the pH value is measured by the pH sensor 110,
When the measured pH value does not reach the set pH value, the control unit 108 switches the ladder resistances R30 to R50 to adjust the electrolysis level to perform the optimum pH adjustment. In the case of FIG. 6, the output of the double-wave rectifier circuit 100 is converted into a direct current by the regulator 101, and the electrolytic level is adjusted by switching the ladder resistance. However, the tap of the power transformer (for example, 4-step switching)
An electrolytic level switching system of the pulsating flow electrolytic power supply by switching may be used.

[0005]

However, in the conventional method shown in FIG. 6, since a large current of several amperes flows as the electrolytic current, the capacity of each component also becomes large and it is necessary to take measures against heat generation. is there.

The present invention has been made in view of the above problems, and an ion water generator capable of overcurrent protection by stable fold-back characteristic control with a simple circuit structure that does not hinder the heat generation of each component. It is an object of the present invention to provide an overcurrent protection device in.

[0007]

In order to achieve the above-mentioned object, the present invention applies an electrolysis power supply containing a ripple component due to single-phase double-wave rectification or the like between electrodes of an electrolysis cell to electrolyze to generate ionic water. In the generated ionized water generator, a comparator detects the change in ripple of the electrolysis current and passes it to the control unit as a current value input, and the duty ratio of the current value input is calculated to determine the electrolysis current value. To detect the overcurrent and send out a voltage setting output for overcurrent protection control based on the "folded characteristic", and the SCR gate of the rectifier circuit is controlled by the voltage setting output to generate an electrolytic output. It is characterized in that a voltage setting block for adjusting is provided.

[0008]

With the above configuration, the control unit calculates the duty ratio from the current value input detected by comparing the ripple change amount of the electrolytic current in the current detection block with the comparator, determines the overcurrent, and sets the voltage setting. Send the voltage setting output to the block. In the voltage setting block, by controlling the SCR gate of the rectifier circuit according to the voltage setting output, the output control by the foldback characteristic is performed, so in response to overcurrent detection,
It is possible to perform more stable protection processing by controlling the fold-back characteristic.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an overcurrent protection device in an ionized water generator according to an embodiment of the present invention.

In FIG. 1, 1 is a power transformer, and 2 is a current detection block for detecting a pulsating flow (ripple component) obtained by rectifying the AC input from the power transformer 1 and sending it as a current value input to a control unit. Reference numeral 3 denotes a control unit that determines the overcurrent value of the electrolytic current by calculating the duty ratio of the current value input from the current detection block 2 and outputs a voltage setting signal.
Is the SCR of the rectifier circuit according to the voltage setting signal from the control unit 3.
It is a voltage setting block that controls the turn to adjust the electrolytic current. Reference numeral 5 is an electrolytic cell to which an electrolytic current is supplied from the voltage setting block 4.

FIG. 2 is a detailed circuit diagram of the embodiment shown in FIG. In FIG. 2, 6 is a diode D1, D2 and SC
It is a single-phase double-wave rectification circuit by R, and G1 and G2 are each SC
The gate of R is shown. Co is a smoothing capacitor, the output of which is supplied to the electrolytic cell 5 as an electrolytic power source.

R1 and R2 are resistors for detecting electrolytic current, R4 and
R5 is a reference value setting resistor, 7 is a comparator for generating a current value input, and outputs the current value input to the current value input port A of the control unit 3. Tr3 is a transistor switch which is turned on / off by a signal from the voltage setting output port C of the control unit 3, and 8 is a pulse transformer for generating a trigger for the SCR gates G1 and G2 corresponding to the voltage setting output. As described above, the resistors R1, R2, R4, R
5, the comparator 7 constitutes the current detection block 2, and the rectifying bridge 6, the smoothing capacitor Co, the pulse transformer 8 and the transistor switch Tr3 constitute the voltage setting block 4. Incidentally, the circuit of the comparator 7 can be omitted by connecting it with a dotted line when the microcomputer of the control unit 3 has a built-in A / D converter.

When the electrolysis level (electrolysis voltage level supplied to the electrolysis cell 5) is a high level (for example, corresponding to 3 or 4 steps of electrolysis levels 1 to 4), an "H" signal is output from the B port of the control unit 3. It is sent out and voltage correction is performed by Tr1 and C1, Tr2 and R3.

FIG. 3 is a flowchart of the processing of the control unit shown in FIG. FIG. 4 is a timing explanatory diagram of waveforms in the current detection block shown in FIG. FIG. 5 is a “fold-back characteristic” curve of the voltage / current overcurrent protection control in the embodiment.

Next, the operation will be described. In the electrolytic output from the rectifier circuit 6 shown in FIG. 2, the ripple component shown in FIG. 4 increases as the electrolytic output current increases when the electrolytic capacitor Co is constant. Therefore, the electrolytic output including the ripple component is divided by R1 and R2 and limited to, for example, 5 V or less, and then the output having the L level and the duty ratio t / T as shown in FIG. That is, the current value input is input to the control unit 3, and an increase in the electrolytic current (overcurrent) is captured as an increase in the ripple by the change in the L level and the duty ratio t / T, and the overcurrent protection control is performed.

For specific processing during this period, referring to FIG. 3, the control unit 3 calculates the L level and the duty ratio t / T by inputting the current value to the A port, and calculates the current value "L" level duty. It is determined whether the ratio t / T is 50% or more (step S-10). When t / T is 50% or less, the process is returned and this loop is repeated.

When t / T becomes 50% or more, the control section 3 sends out a voltage setting output signal corresponding to the current value converted from the counted duty ratio t / T from the C port to turn on the switch Tr3. Turn on and trigger the SCR G1 and G2 gates to set the turn-on time of the SCR to t / T
The voltage setting output down process is performed so as to reduce the ratio and the electrolytic voltage / current from the rectifier circuit 6 (step S-11).

Further, the "L" level duty ratio t / T
Is above 60% (step S-1)
2). If t / T continues to increase to 60% or more, the voltage setting output down process is continued (step S-13),
Finally, it is determined whether the "L" level duty ratio t / T is 90% or more (step S-14). When t / T is 90% or more, the SCR of the rectifier circuit 6 is controlled to be turned off, and the electrolytic voltage output supplied to the electrolytic cell 5 is controlled to 0 (step S-15).

If the overcurrent protection process is performed stepwise in this manner,
As shown in FIG. 5, a stable overcurrent protection system is constituted as compared with the control of the acute drooping characteristic by the conventional cut-off process having the current-voltage control “fold-back characteristic” curve. As described above, the electrolytic level (for example, 15
V, 18V, 24V and 28V)
In the case of high level 3 and 4, the correction circuits of Tr1 and Tr2 perform input correction to detect respective overcurrents.

In this embodiment, the ripple value of the electrolytic current is detected to generate the current value input signal,
Since the overcurrent is judged from the change of the "L" level duty ratio t / T and the electrolytic output is controlled according to the "folded characteristic" by the voltage setting output, automatic electrolytic level control and stable "folded characteristic" are provided. It is possible to construct an overcurrent protection device.

[0021]

As described above, according to the present invention,
A current detection block that compares and detects changes in the ripple component of the electrolytic current with a comparator and passes it as a current value input to the control unit.
The control unit that detects the overcurrent by calculating the duty ratio of the current value input and judges the electrolytic current value, and sends out the voltage setting output for the overcurrent protection control due to the "fold-back characteristic", and the voltage With a voltage setting block that controls the SCR gate of the rectifier circuit by setting output and adjusts the electrolytic power supply, overcurrent protection of the ion water generator has a simple structure with fewer parts for current cutting, and there is no fear of heat generation. There is an effect that an overcurrent protection device that automatically satisfies the "fold-back characteristic" control can be configured.

[Brief description of drawings]

FIG. 1 is a block diagram of an overcurrent protection device in an ionized water generator according to an embodiment of the present invention.

FIG. 2 is a specific circuit diagram of the embodiment shown in FIG.

FIG. 3 is a flowchart of processing of a control unit shown in FIG.

FIG. 4 is an explanatory diagram of a duty ratio of a current value input.

FIG. 5 is a diagram showing a fold-back characteristic curve.

FIG. 6 is a configuration diagram of a conventional ionized water generator.

[Explanation of symbols]

 1 Power Transformer 2 Current Detection Block 3 Controller 4 Voltage Setting Block 5 Electrolyzer

Claims (1)

[Claims] 1. A ripple component of an electrolysis current in an ion water generator that produces electrolyzed water by applying an electrolysis power source including a ripple component due to single-phase double-wave rectification or the like between electrodes of an electrolytic cell to produce electrolyzed water. Is detected by comparing with a comparator and passed to the control section as a current value input, and an overcurrent detection is performed by judging the electrolytic current value by calculating the duty ratio of the current value input, and the "folded characteristic" And a control unit for sending a voltage setting output for overcurrent protection control by the
An overcurrent protection device for an ionized water generator, comprising a voltage setting block for controlling an R gate to adjust an electrolytic output.