JPH0449145Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) This invention relates to a high voltage generation circuit for an ozone generator.

(Prior Art) Ozone is a gas that has sterilizing power. Taking note of its sterilizing power, ozone generators are installed in commercial refrigerators or in commercial bath facilities.

FIG. 4 shows an example of such an ozone generator. That is, this ozone generator includes an air compressor 1, a rotary ozone generator 3 that communicates with the compressor 1 via a blow pipe 2, and has a rotary discharge electrode 3A and a fixed discharge electrode 3B disposed therein. , a high voltage generating circuit 4 that generates a high voltage to be applied to the electrodes 3A and 3B, and a motor 6 that rotates the compressor 1 and the rotating electrode 3B by a shaft 5.

As the compressor 1 operates, air is sucked in through the suction pipe 1a, compressed within the compressor 1, and then discharged from the discharge pipe 1b. The compressed air discharged from the discharge pipe 1b passes through the blast pipe 2 and is introduced into the ozone generator 3 from the introduction pipe 3a. Discharge electrode 3A in this ozone generator 3,
A high voltage from the high voltage generation circuit 4 is applied to 3B, and discharge occurs. This discharge generates ozone, and the air containing the ozone is discharged to the outside from the discharge pipe 3b.

FIG. 5 is a circuit diagram showing details of the high voltage generating circuit 4 described above. The high voltage generation circuit 4 inputs an AC low voltage from a commercial power source, etc., converts it into a substantially AC high voltage, and converts it into the discharge electrodes 3A, 3B in the ozone generator 3.
supply to.

The operation of this high voltage generating circuit 4 will be explained in more detail. An AC voltage such as a commercial power source is applied to the input terminal 9. This AC voltage is rectified by a noise prevention filter 10a and a rectifier bridge 10b of the DC power supply circuit 10 to become a DC voltage.

The positive terminal 10b ₁ of the rectifying bridge 10b is connected to the primary winding 7 of the high voltage transformer 7 via the reactor L ₁ .
It is connected to one terminal _7a1 of a. The reactor _L1 forms part of an oscillation circuit that will be described later. The other terminal 7 of its primary winding 7a
a ₂ is connected to the rectifier bridge 10b via the thyristor SCR
is connected to the negative terminal _{10b2 of} . With the above connections, the positive and negative terminals 10b ₁ of the rectifier bridge 10b,
A main circuit is connected between 10b and ₂ .

The main circuit is turned on and off by a chopper control circuit 11 equipped with a thyristor SCR. This chopper control circuit 11 causes the thyristor SCR to function as a DC chopper. That is, the DC voltage obtained by the rectifier bridge 10b is
The pressure is divided by R ₁ and R ₂ . The divided voltage is applied to the resistor R ₃
and is applied to capacitor _C1 via variable resistor VR. Their resistance R ₃ , VR and capacitor C ₁ are
This constitutes the RC integration circuit 11a. Capacitor C ₁ has a time constant (r ₃ + vr) c ₁ [r ₃ , vr is resistance
The charging voltage increases at a speed corresponding to the values of R ₃ , the resistance value of VR, and c ₁ the capacitance of the capacitor C ₁ . When the charging voltage reaches a predetermined value, the DIATSU (product name) TD
becomes conductive and a trigger pulse is applied to the thyristor SCR. That is, due to the conduction of the diac TD,
The charge in the capacitor _C1 is discharged through the resistor _R4 , the gate G and the cathode K of the thyristor SCR, and is also discharged through the resistor _R5 . The thyristor SCR is turned on by discharge through the gate G and cathode K of the thyristor SCR, that is, by the trigger pulse. When it is turned on, current flows through the main circuit. That is, current flows from the positive terminal 10b ₁ of the rectifier bridge 10b to the negative terminal 10b ₂ via the reactor L ₁ , the primary winding 7a of the high voltage transformer 7, and the thyristor SCR. As the thyristor SCR turns on, the charge in the capacitor _C2 is further discharged. That is, the charged charges are discharged through the terminals 7a ₁ and 7a ₂ of the primary winding 7a of the high voltage transformer 7 and the thyristor SCR. The discharge circuit used for the discharge includes the capacitor C ₂ and the primary winding 7a.
constitutes an oscillation circuit together with the reactor _L1 mentioned earlier. Therefore, once the charge charged in the capacitor C ₂ in the direction shown in FIG. 5 is discharged, the capacitor C ₂ is charged in the opposite direction. As a result, a voltage is applied to the thyristor SCR in the opposite direction, causing it to switch from on to off. As a result, the primary winding 7a of the high voltage transformer 7
The current flowing to stops instantaneously. The above operations are repeated continuously. As a result, a pulse current flows through the primary winding 7a of the high voltage transformer 7.

Note that the series circuit of a resistor R ₆ and a capacitor C ₃ connected in parallel to the primary winding 7a of the high voltage transformer 7 is as follows:
This is a snubber circuit for absorbing surges. Further, the diode D connected in parallel to the thyristor SCR is a noise prevention diode for protecting the thyristor.

As described above, since the pulse current repeatedly flows instantaneously through the primary winding 7a of the high voltage transformer 7, a high voltage is induced in the secondary winding 7b.
The high voltage is applied to the fixed and rotating discharge electrodes 3A and 3B of the rotary ozone generator 3. As a result, discharge occurs between the electrodes 3A and 3B, and ozone is generated.

Variable resistance VR in the above RC integration circuit 11a
By changing the resistance value of the trigger pulse, it is possible to change the timing at which the trigger pulse is generated, that is, the interval at which the trigger pulse is generated. That is, variable resistance
If the resistance value of VR is increased, it will take a longer time for the charging voltage of capacitor _C1 to reach a predetermined value.
Conversely, if the resistance value is made small, the charging voltage will reach the predetermined value in a short time. Therefore, the trigger pulse generation timing, that is, the generation interval changes. By controlling the interval of its occurrence, the high voltage transformer 7
energization to the primary winding 7a is controlled, and the secondary winding 7a is controlled.
The voltage applied to the discharge electrodes 3A, 3B connected to the electrodes b is also controlled. Thereby, the amount of ozone generated is controlled.

When using an ozone generator like the one above,
The amount of ozone generated by discharge generally decreases in summer and increases in winter. This is because there is a correlation between the amount of ozone generated by discharge, temperature, and humidity, and the temperature and humidity are high in the summer, and the temperature and humidity are low in the winter.

FIG. 3 is a characteristic curve showing an example of the relationship between the amount of ozone generated by discharge and temperature when the humidity is (60±10)%. Curve A is for the conventional example, and as is clear from curve A, by comparing the cases where the temperature is 1°C and 35°C, it can be seen that the amount of ozone generated is significantly different. Afterwards,
If left as is, the ozone concentration will become abnormally high or low.

Therefore, in the past, the ozone concentration was adjusted by manually changing the resistance value of the variable resistor VR between summer and winter.

(Problem to be Solved by the Invention) However, it is difficult to manually set the resistance value of the variable resistor VR to an optimal value depending on the temperature and humidity. That is, the temperature, humidity, and other conditions of the ozone generation environment in which ozone is generated by discharge are not always constant, but often fluctuate. In addition, it is often difficult for the user to reset the resistance value of the variable resistor VR each time in response to such fluctuations.

This idea was made in view of the above circumstances, and its purpose is to generate ozone that can automatically control the amount of ozone generated by discharge even if the temperature and humidity of the air near the discharge electrode changes. An object of the present invention is to provide a high voltage generation circuit for a device.

[Structure of the idea]

(Means for solving the problem) The high voltage generation circuit for an ozone generator of the present invention is
A main circuit in which a power supply, the primary winding of a high-voltage transformer, and a switching element are connected in series; and an RC integration circuit connected to the power supply, and the charging voltage of the capacitor in the RC integration circuit reaches a predetermined value. At the same time, the capacitor is discharged, and the charging and discharging operation is repeated, and the switching element is turned on by the trigger pulse obtained by the discharge, thereby repeatedly making the main circuit momentarily conductive. In the high voltage generation circuit for an ozone generator, the AC high voltage to be applied to the discharge electrode of the ozone generator is obtained on the secondary side of the high voltage transformer. It is configured to use a sensor that detects at least one of temperature and humidity, and whose resistance value decreases as the detected value increases.

(Function) The capacitor of the RC integration circuit is repeatedly charged and discharged.
A trigger pulse obtained by the discharge turns on the thyristor. When it turns on, the main circuit momentarily becomes conductive and repeats this process. The capacitor is discharged when the charging voltage of the capacitor reaches a predetermined value. The time required for the charging voltage to reach a predetermined value is determined by the time constant RC of the RC integration circuit. The resistance that determines the time constant is determined by the resistance of a sensor that detects at least one of the temperature and humidity of the discharge atmosphere.
The sensor decreases the resistance value as the detected value increases. Therefore, the resistance value of the sensor becomes small in the summer when both temperature and humidity rise, and becomes large in the winter when the temperature and humidity drop. Therefore, in summer, the above-mentioned time constant becomes small, the capacitor is frequently discharged, and the thyristor, that is, the main circuit is frequently turned on. Conversely, in winter, the time constant increases, the number of times the capacitor is discharged is reduced, and the number of times the thyristor, ie, the main circuit, is turned on is reduced.

As the number of times the main circuit is turned on increases or decreases, the voltage applied to the discharge electrode via the secondary winding of a high voltage transformer having a primary winding connected to the main circuit increases or decreases. When the voltage applied to the discharge electrode increases or decreases, the amount of ozone generated by discharge at the discharge electrode increases or decreases. Therefore, in the summer, the voltage applied to the discharge electrode increases to suppress a decrease in the amount of ozone generated, and in the winter, the applied voltage decreases to suppress an abnormal increase in the amount of ozone generated.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a high voltage generation circuit 4A as an embodiment of the present invention. This high voltage generation circuit 4A is
The difference from the high voltage generation circuit 4 of FIG. 5 is that a thermistor 12 is used in place of the resistor R ₃ of the RC integration circuit 11a of FIG. The thermistor 12 is installed inside the blast pipe 2. The other configurations in FIG. 1 are the same as in FIG. 5. Therefore, in FIG. 1, the same components as those in FIG. 5 are given the same reference numerals, and their explanations will be omitted.

FIG. 2 shows the entire ozone generator incorporating the high voltage generating circuit 4A of the above embodiment. As is clearer from the figure, the thermistor 12 is provided on the outlet side of the blast pipe 2. The installation position of the thermistor 12 is not limited to the above, but may be any position as long as it can detect the temperature of the air inside the rotary ozone generator 3 or the temperature of the air sent there. Then,
For example, it can be installed inside the suction port 1a of the compressor 1 or the rotary ozone generator 3.

Next, with reference to FIG.
The explanation will focus on A. Choppa control circuit 11A
The RC integration circuit 11a ₀ in the thermistor 12,
It is composed of a variable resistor VR and a capacitor _C1 . The resistance value of the thermistor 12 changes depending on the temperature of the air flowing inside the blast pipe 2. That is, the temperature of the air passing through the blast pipe 2 decreases in winter, and increases in summer. As the temperature of the air increases or decreases, the resistance value of the thermistor 12 decreases or increases accordingly. Depending on the increase or decrease of the resistance value, the RC integration circuit 1
1a ₀ time constant increases or decreases. By increasing or decreasing the time constant, the conduction of the diac TD, that is, the timing of the generation of the trigger pulse for the thyristor SCR, changes slowly, similar to when the time constant is changed by changing the resistance value of the variable resistor VR in Fig. 5. . That is, in winter, the resistance value of the thermistor 12 increases and the interval between the occurrences of the trigger pulse becomes longer. As a result, the voltage applied to the discharge electrodes 3A and 3B by the rotary ozone generator 3 is reduced, and an abnormal increase in the amount of ozone generated is suppressed. On the other hand, in summer, the resistance value of the thermistor 12 decreases, and the interval between the generation of the trigger pulses becomes shorter. Thereby, the voltage applied to the discharge electrodes 3A, 3B of the ozone generator 3 increases, and a decrease in the amount of ozone generated is suppressed.

Curve B in FIG. 3 thus represents the thermistor 12.
This is a characteristic curve showing the relationship between the amount of ozone generated and the temperature when the sensor is installed. According to this curve B, it is clear that the amount of ozone generated remains almost constant even when the temperature changes significantly. In other words, the user can generate ozone evenly in both summer and winter without adjusting the variable resistor 8.

Instead of the thermistor 12, a humidity sensor whose resistance value decreases and increases as the humidity increases and decreases can also be used. As mentioned above, humidity, like temperature, increases in the summer and decreases in the winter. Therefore, if such a humidity sensor is used, it will function similarly to a thermistor and automatically control the amount of ozone generated.

Furthermore, it is also possible to switch between the thermistor and the humidity sensor. It is also possible to use a sensor whose resistance value has a negative coefficient for both temperature and humidity.

[Effect of idea]

According to the high voltage generation circuit for an ozone generator of the present invention, the voltage applied to the discharge electrode from the secondary side of the high voltage transformer is automatically adjusted by focusing on at least one of the temperature and humidity of the air near the discharge electrode. Since the temperature and humidity are changed, the amount of ozone generated can be averaged even if the temperature and humidity near the discharge electrode change.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of an embodiment of the present invention, Fig. 2 is a block diagram showing the entire ozone generator incorporating an embodiment of the present invention, and Fig. 3 is an ozone generation amount and temperature according to the present invention and a conventional example. Characteristic diagram showing the relationship between
The figure is a block diagram of a conventional ozone generator, and FIG. 5 is a circuit diagram of a conventional high voltage generating circuit. 4A...High voltage generation circuit, 7...High voltage transformer, 7a...Primary winding, 10...DC power supply circuit,
11A... Phase control circuit, 11a ₀ ... RC integration circuit, 12... Thermistor, SCR... Thyristor,
TD...Diatsuku (product name).

Claims (1)

[Claims for Utility Model Registration] A main circuit in which a power supply, the primary winding of a high-voltage transformer, and a switching element are connected in series; an RC integration circuit connected to the power supply; When the charging voltage reaches a predetermined value, the charge in the capacitor is discharged, the charging and discharging operation is repeated, and the switching element is turned on by a trigger pulse obtained by the discharge, thereby turning on the main circuit. In a high voltage generation circuit for an ozone generator, which repeats instantaneous conduction to obtain an AC high voltage to be applied to the discharge electrode of the ozone generator on the secondary side of the high voltage transformer, as a resistor in the RC integration circuit. , a high voltage generator for an ozone generator, characterized in that a sensor is used that detects at least one of the temperature and humidity of the air near the discharge electrode, and whose resistance value decreases as the detected value increases. circuit.