JP2547471B2 - Ozone generation circuit - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ozone generation circuit that applies a high voltage to a creeping discharge body to generate ozone.

(B) Conventional technology In an ozone generator, a high voltage obtained by boosting an AC signal from a self-excited oscillator with a step-up transformer is applied to a creeping discharge body having a fine ceramic as a dielectric layer, and the creeping discharge body discharges air. There is one that is made to react with to obtain ozone. In this type of ozone generator, a piezoelectric element is attached to the discharge element for ozone generation, in order to prevent problems during discharge such as prevention of deposits (dirt) and improvement of nitrate mist, etc. Another power source is provided to drive the piezoelectric element (Japanese Patent Laid-Open No. 62-201638, 63-190702).
issue).

(C) The problem to be solved by the invention With the creeping discharge body provided with the above-mentioned piezoelectric element, when the resonance frequency of the piezoelectric element is driven at about 2 KHz to 8 KHz, it vibrates most efficiently, but because of the audible temperature range, There is a problem that it may be offensive to the ears and the use is restricted. Further, if the resonance point is shifted even a little, the vibration range becomes extremely small, so that there is a problem in that individual adjustment is required for product management. On the other hand, vibration at a resonance frequency (18 KHz or more) beyond the audible range requires a high voltage, and if this is realized by an independent drive circuit, there is a problem that the entire device becomes expensive.

The present invention has been made in view of the above problems, and can be driven at a frequency exceeding an audible frequency, and further, without requiring a special drive circuit that is so expensive,
An object is to provide an ozone generation circuit that can drive a piezoelectric element.

(D) Means and Actions for Solving the Problems The ozone generation circuit of the present invention applies the voltage boosted by the drive transformer to the creeping discharge body to generate ozone, and also deposits and dirt on the creeping discharge body. In a device additionally provided with a piezoelectric element for removing the above, the tap voltage is taken out from the winding of the drive transformer and applied to the piezoelectric element.

In this ozone generation circuit, the tap voltage is taken out from the winding of the drive transformer and applied to the piezoelectric element, so the voltage to the piezoelectric element can be set freely by changing the tap, and a special circuit is provided. It is possible to apply a voltage of a required frequency and level to the piezoelectric element without separately providing it.

(E) Examples Hereinafter, the present invention will be described in more detail with reference to Examples.

FIG. 1 is a circuit connection diagram of an ozone generation circuit showing an embodiment of the present invention. In the figure, reference numeral 1 is a creeping discharge body for ozone generation using a fine ceramic as a dielectric layer, and a piezoelectric element 2 is attached to prevent adhered substances (dirt). The secondary winding N _s of the step-up transformer 3 is connected to both electrodes of the creeping discharge body 1, and the primary winding A of the step-up transformer 3 is A.
One end of the DC power supply 4 is connected to the point, and the other end of the DC power supply 4 is connected to the point B of the step-up transformer 3 via the emitter and collector of the transistor 6. The oscillation source 5 is connected to the base of the transistor 6. Further, the primary winding of the step-up transformer 3 to the winding N _P1, further winding N _P2
Is further wound, and the tap C point and the tap A point are connected to the piezoelectric element 2.

In this ozone generation circuit, the DC voltage of the DC power supply 4 turns on / off the transistor 6 by the signal from the oscillation source 5.
Accordingly, the voltage V ₁ boosted by the step-up transformer 3 at a ratio of N _s / N _P1 is applied to the creeping discharge body 1 by self-excited oscillation including the transistor 3, and the creeping discharge body 1 is discharged. At that time, the air reacts to generate ozone. Also, with winding N _P1 ,
A voltage V ₂ due to N _P2 further wound around the winding N _P1 is applied to the piezoelectric element 2 to vibrate the piezoelectric element 2.

In this circuit, the voltage of the power supply 4 is now set to DC12V and the discharge voltage V
_{When 1} = 2800V _PP and the frequency of the oscillation source 5 is 19.5 KHz, the voltage V ₂ of the piezoelectric element ₂ is 50 V _PP (sine wave), and the desired vibration effect is obtained. In the conventional technology, when the piezoelectric element drive circuit is provided separately from the step-up transformer 3,
Compared to the fact that the vibration effect was extremely small, only controllable up to KHz and 20V _PP, it was a remarkable advance.

FIG. 2 is an overall circuit diagram of an ozone generator incorporating the embodiment circuit of FIG.

In FIG. 2, the circuit portion 30 is the circuit portion shown in FIG. Specifically, the circuit portion 31 is the circuit shown in FIG. In the circuit part 31, a resistor R ₄ and a capacitor
C ₃ , transistor 6, step-up transformer 3 and creeping discharge body 1
The transformer coupled self-excited oscillation circuit is configured to apply high voltage to the creeping discharge body 1. One end of the secondary winding N _s of the step-up transformer 3 is connected to GND (ground) via the resistor R _5.
It is connected. The resistor R ₅ constitutes the discharge current detection circuit 9. Step-up transformer N _s and one end of the capacitor C ₁ to the connection point of the resistor R ₅ is connected, the other end of the capacitor C ₁ is connected to the base of the transistor 7, the capacitor C ₁
A resistor R ₁ is connected between the other end of and. The capacitor C ₁ and the resistor R _{1 form} a filter 10. The transistor 7 is provided for amplifying the signal from the filter 10, the emitter is connected to GND, and the collector is connected to the + 12V power source via the resistor R ₃ .
A rectifying diode D is connected to the collector of the transistor 7, and a parallel circuit of a capacitor C ₂ and a resistor R ₂ is connected to the output side of the diode D to control the oscillation state of the self-excited oscillation circuit. It is connected to the base of the transistor 8. The resistor R ₄ is a variable resistor and is used for adjusting the oscillation intensity.

In the circuit portion 31, the waveform of the current flowing through the creeping discharge body 1 is as shown in FIG. The middle waveform a is the main component, which is the charging / discharging current flowing in the capacitor component between the discharge electrodes, and has a frequency of 20 KHz to 40 KHz. Waveform b is 1 μsec that is superimposed on the main component due to discharge in air
Pulsed noise (1MHz or more) or more. This component b is proportional to the discharge strength in air. Therefore, in the embodiment, the resistance R ₅ detects the current flowing in the creeping discharge body 1,
Further, only the pulse component b is derived by the filter 10, this is amplified by the transistor 7, further rectified by the diode D, and the DC voltage smoothed by the smoothing circuit 11 is fed back to the transistor 8. When the feedback voltage becomes large, When the self-sustained pulsation is weakened and conversely the feedback voltage becomes small, the self-sustained pulsation is strengthened, and as a result, a constant discharge amount is obtained by feedback control. The resistance
The feedback response speed is stabilized by the time constant of R ₂ and capacitor C ₂ .

In the circuit portion 32 of FIG. 2, P ₁ is a + power supply connection terminal,
The fan 22 is connected to the terminals P ₂ and P ₄ , and the terminal P ₃ is
A pulse signal corresponding to the rotation speed of the fan 22 is derived. This is the terminal P ₃ are integrated circuits configured constituted by capacitor C _5, R _7, the terminal P ₃ are connected to the set input S of the flip-flop 14 via the OR circuit 12, the AND circuit 13.
When the switching waveform at the terminal P ₃ exceeds the threshold level, the flip-flop 14 is set to detect the fan abnormality and sets the flip-flop 14. Similarly, a part of the current (20 KHz) of the creeping discharger 1 is taken out by the resistors R ₅ and R ₆ , and the flip-flop 1 is connected via the OR circuit 12 and AND 13.
It is added to the set input terminal S of 4. The resistors R ₆ and R ₅ are selected so that the threshold level voltage of the flip-flop 14 is obtained with a current that is about twice that in the normal state. The timer 16 is provided, the resistance rising voltage at power ON R _8, OR
Reset timer 16 via circuit 15 then AN in 2 seconds
Input logic "1" to D circuit 13 and output "10 minutes" to OR circuit 1
After 5 it resets itself. Flip flop 14
The output terminal Q of is connected to the ON / OFF switches 17 and 18. When the set output Q = "1", the ON / OFF switches 17 and 18 are OF
It is supposed to F.

Assuming that the fan 22 is rotating normally in the circuit portion 32 of this ozone generator, the waveform input to the terminal P ₃ is up to t _{1 in} FIG. The input of does not exceed the threshold level TH. Therefore, flip-flop 14 is not set. However, when the rotation speed of the fan drops to below 60 _rpm ,
As shown at time t _{2 in} FIG. 5, the threshold level TH
After that, the flip-flop 14 is set, and by the set output Q, the switches 17 and 18 are turned off, the discharge is stopped, and the power supply to the fan is cut off.
However, as described above, since one end of the AND circuit 13 does not become "1" for about 2 seconds after the operation starts, the flip-flop 14 is not set, and therefore the cutoff function does not work.

Even if the fan is operating normally, if an abnormally large current flows due to water drops, etc., the resistances R ₅ and R ₆
The voltage input to the OR circuit 12 becomes large, exceeds the threshold level, and the flip-flop 14 is set. With this set output, the switch 17 is turned off, the discharge is stopped, the switch 18 is also turned off, and the fan also stops operating.

The flip-flop 14 is reset by the 10-minute signal of the timer 16, and in the case of an instantaneous abnormality, it can be used again after 10 minutes.

(F) Effects of the Invention According to the present invention, since the power source for driving the piezoelectric element is derived from the voltage of the tap of the step-up transformer and used, a separate power source for driving the piezoelectric element is not required and the cost is low. Moreover, it is possible to obtain an ozone generation circuit that can apply a desired applied voltage according to each specification.

[Brief description of drawings]

FIG. 1 is a circuit connection diagram of an ozone generating circuit showing an embodiment of the present invention, FIG. 2 is a circuit connection diagram of an entire circuit of an ozone generating apparatus incorporating the ozone generating circuit of the embodiment, and FIG. FIG. 4 is a circuit connection diagram showing a partial circuit of the ozone generator, FIG. 4 is a waveform diagram for explaining the operation of the partial circuit of the ozone generator, and FIG. 5 is another circuit of the ozone generator. It is a waveform diagram for explaining the operation of the part. 1: Creeping discharge body, 2: Piezoelectric element, 3: Step-up transformer

Claims (1)

(57) [Claims] 1. A method for applying a voltage boosted by a drive transformer to a creeping discharge body to generate ozone, and at the same time, providing a piezoelectric element for removing deposits and dirt on the creeping discharge body. In the circuit, the tap voltage is taken out from the winding of the drive transformer and applied to the piezoelectric element.