JPH03285803A - Ozone generating circuit - Google Patents

Abstract

PURPOSE:To obtain an ozonizer with a simple circuit constitution and without being significantly affected by humidity by controlling the output pulse width of a pulse generator in accordance with a silent discharge current. CONSTITUTION:The output of a pulse generator 1 is transmitted to the base of a transistor 2 to drive a pulse transformer 3. A creeping discharge body 4 is connected as the load of the secondary winding 32 of the transformer 3. When the primary winding 31 of the transformer 3 is driven by the transistor 2, a high voltage is induced in the secondary winding 32 of the transformer 3 immediately after the transistor 2 is turned off. A damped vibration is then caused at a frequency determined by the inductance of the secondary winding 32, distributed capacity, capacity of the creeping discharge body 4, etc. When a creeping discharge is started by the creeping discharge body 4, the vibration is superimposed on a damped vibration current, and a pulse silent discharge current is observed. The ozone generating circuit is controlled so that the detected output of a silent discharge current is fixed, and the creeping discharge is relatively uniformized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ozone generation circuit that drives a creeping discharge body with a pulse transformer.

Conventional technology Ozone generation using a creeping discharge device is relatively stable in a low-temperature, low-humidity atmosphere, such as inside a refrigerator. Taking advantage of this, deodorization technology that combines low concentration ozone and an oxidation catalyst has been developed. (This is known. In this case, the creeping discharge body is driven by supplying pulse energy with a small duty factor at regular intervals, and even if the discharge atmosphere changes, the input energy to the creeping discharge body remains constant. It doesn't change.

Problems to be Solved by the Invention However, when trying to obtain a relatively low concentration of ozone (several ppm or less) at room temperature and humidity using such a creeping discharge device, the discharge may not start, or Another problem is that it takes a long time for the discharge to spread over the entire surface discharge body.

A first object of the present invention is to provide an ozone generator that has a simple circuit configuration and is less affected by the discharge atmosphere, particularly humidity.

A second object of the present invention is to provide an ozone generation circuit with high ozone generation efficiency.

Still another object of the present invention is to provide ozone generation that is less affected by fluctuations in power supply voltage and changes in ambient temperature.

Means for Solving the Problems In order to achieve the above object, the ozone generator of the present invention includes a pulse generator, a transistor and a pulse transformer driven by the output of the pulse generator, and a secondary transistor of the pulse transformer. The pulse generator consists of a creeping discharge body connected to the winding, a detection circuit for the silent discharge current generated when the creeping discharge body performs silent discharge, and a secondary winding current detection circuit of the pulse transformer. The output pulse generation timing of the pulse generator is synchronized with the current phase of the damped oscillation formed by the secondary winding and the creeping discharge body, and at the same time, the output pulse width of the pulse generator is controlled in accordance with the silent discharge current. By doing so, creeping discharge can be made uniform.

Operation The ozone generating circuit of the present invention detects the silent discharge current component and controls the output pulse width of the pulse generator in accordance with this detected value. Therefore, if the humidity of the discharge atmosphere is high (and silent discharge is unlikely to occur), the output pulse width is increased and the energy supplied to the pulse transformer is increased until the silent discharge current component can be detected. , when the discharge starts and the silent discharge current increases, the output pulse width is returned to a small value to ensure a constant ozone concentration.In addition, the ozone generation efficiency depends on the secondary winding of the pulse transformer and the creeping discharge body. The ozone generation circuit of the present invention is provided with a secondary winding current detection circuit, although it is greatly influenced by which phase of the free oscillation current waveform formed by the next drive pulse is supplied. , pulse energy is always supplied at a phase in which ozone generation occurs with high efficiency.

Example Hereinafter, the present invention will be described in detail based on examples.

FIG. 1 is a diagram showing the configuration of an embodiment of the ozone generation circuit of the present invention. The output of the pulse generator 1 is applied to the base of a transistor 2 to drive a pulse transformer 3. The creeping discharge body 4 acts as a load on the secondary winding 32 of the pulse transformer 3.
is connected. When the primary winding 31 of the pulse transformer 3 is driven by a pulse by the transistor 2, the secondary winding 32 of the pulse transformer 3 has the transistor 2 turned off.
Immediately after that, a high voltage is induced, and after that, the secondary winding 3
Damped oscillation is performed at a frequency determined by the inductance of 2, the distributed capacitance, the capacity of the surface discharge body 4, etc. When the creeping discharge body 4 starts creeping discharge, a pulsed silent discharge current is observed superimposed on the damped oscillating current. Generally, the vibration frequency of damped vibration is 10 to 100 KHz, whereas the pulse width of silent discharge current is 10 to 100 ns, and there is a significant difference in the frequency spectra of the two.

5 is a silent discharge current detection circuit that separates the silent discharge current waveform from the damped oscillation waveform. In the ozone generation circuit shown in FIG. 1, when the relative humidity of the discharge atmosphere increases, creeping discharge occurs and the output of the silent discharge current detection circuit becomes smaller. As a result, the output pulse width of the pulse generator 1 controlled by the output of the silent discharge current detection circuit increases, the energy supplied to the pulse transformer 3 increases, and the high voltage applied to the creeping discharge body 4 increases. The amplitude increases, the creeping discharge becomes stronger, and the silent discharge current increases. Conversely, when the discharge atmosphere is in a low temperature and dry state, creeping discharge is likely to occur, the detection output of the silent discharge current increases, and the pulse width of the pulse generator 1 is controlled to be small.

As described above, it is understood that the ozone generation circuit shown in FIG. 1 is controlled so that the detected output of the silent discharge current component is constant, and therefore the creeping discharge is relatively constant.

FIG. 2 is a diagram showing the configuration of another embodiment of the ozone generation circuit of the present invention. In the figure, 1, 2, 3, 4, 31 and 32 are the same elements and functions as in the embodiment of FIG. 1, and their explanation will be omitted. 6 is a current detection circuit for the secondary winding 32 of the pulse transformer 3. When the transistor 2 is turned on by the output pulse of the pulse generator 1, current flows through the primary winding 31 of the pulse transformer 3, and this energy is transferred to the pulse transformer 3.
is accumulated in When the transistor 2 turns OFF Fm, the energy stored in the transformer 3 during the ON period is released to a free vibration system mainly formed by the secondary winding 32 and the creeping discharge body 4, and damped vibration starts. As the damped vibration progresses, the direction and magnitude of the magnetic flux within the magnetic body of the pulse transformer 3 changes, and this change then causes the primary winding 3 to change.
An output pulse is supplied from the pulse generator 1 to the transistor 2 at a timing facilitated by the energy provided by the pulse generator 1. As a result, the energy stored in the transformer 3 due to the switching of the transistor 2 is efficiently supplied to the creeping discharge body 4.

FIG. 3 is a diagram showing the configuration of another embodiment of the ozone generation circuit of the present invention. In FIG. 3, the elements indicated by 1 to 6 are the same as those of the embodiment shown in FIGS. 1 and 2, and their explanation will be omitted. In the embodiment shown in FIG. 3, the outputs of the silent discharge current detection circuit 5 and the secondary winding current detection circuit 6 inserted into the secondary winding current path of the pulse transformer 3 are used to As explained in FIG. 2 and FIG. 2, the generation timing of the pulse given to the transistor 2 is synchronized with the phase of the damped vibration formed by the secondary winding and the creeping discharge body, and the pulse The width depends on the magnitude of the silent discharge current.

FIG. 4 is a diagram showing the configuration of one embodiment of the silent discharge current detection circuit 5. In FIG. In the figure, 7 is a current detection resistor inserted into the secondary winding current path of the pulse transformer 3. 8 is a high-pass filter that separates the silent discharge current component from the signal component of the detection resistor 7, and the output of this filter is rectified and integrated by the integrating circuit 9, and the pulse of the pulse generator 1 is used as the silent discharge current detection signal. Control width. Other than this, a half-wave rectifier circuit or a peak hold circuit may be used as the integrating circuit 9.

FIG. 5 is a diagram showing the configuration of another embodiment of the silent discharge current detection circuit 5. In FIG. The magnitude of the silent discharge current is not necessarily proportional to the ozone concentration because it is affected by the temperature of the discharge atmosphere. This is thought to be because, in a high-temperature atmosphere, part of the ozone produced by the dielectric breakdown of the air is returned to oxygen by the high-temperature air, whereas the silent discharge current corresponds to the dielectric breakdown of the air. Therefore, in the embodiment of FIG. 5, the output of the integrating circuit 9 is voltage-divided using the temperature sensing element 10 and supplied to the pulse generator J1. Correction is performed using the temperature sensing element 10 so that the ozone concentration is high at high temperatures and low at low temperatures.

Also, high pass filter 8. If the output of the integrating circuit 9 depends on the power supply voltage, the influence of the power supply voltage can be removed by replacing it with the temperature sensing element 10 or by using a voltage non-linear element at the same time as the temperature sensing element 10.

FIG. 6 is a diagram showing the configuration of one embodiment of the secondary winding current detection circuit 6. The zero point of the secondary winding current can be determined by the zero cross detector 11 from the voltage across the detection resistor 7 inserted into the path of the secondary winding current. This zero phase is shifted by a phase shifter 12 and divided by a frequency divider 11413 if necessary. As a result, the output of the divided period 13 becomes information indicating the generation timing of the output pulse of the pulse generator 1.

FIG. 7 is a diagram showing the configuration of another embodiment of the secondary winding current detection circuit 6. The secondary winding current is directed to a zero-crossing detector indicated at 10 and flows through the base-emitter junction of the transistor and a diode inserted between the base and emitter. By changing the magnitude of the collector resistance of the transistor, the gate input waveform of the ozone generation control gate 13 changes, so that the output of the gate 13 is generated in a phase away from the zero-crossing phase of the secondary winding current.

Therefore, in this case, the zero-cross detector ]O includes the function of a phase shifter. Reference numeral 12 denotes a frequency divider using a monostable oscillator with a CMO8' gate, and performs frequency division by invalidating the output signal of the gate 13 only during the hold period of the monostable operation of the oscillator.

FIG. 8 is a diagram showing the configuration of one embodiment of the pulse generator 1. The output of the rectangular wave oscillator 20 is converted to ri by a differentiating circuit 21.
The sing edge is taken out and compared with a reference voltage by a comparator 24. Also, the resistor 23 in the differentiating circuit 21
Since the collector and emitter of the second transistor 25 are connected in parallel to
At the timing of N, the above-mentioned square wave device rising
The amplitude of the edge suddenly becomes small (the comparator 24
The output becomes -LOW. On the other hand, 2 of pulse transformer 3
A silent discharge current detection circuit 5 detects the current flowing in the next winding.
Switch element 3 outputs an output corresponding to the magnitude of the silent discharge current.
0 and the base input of the second transistor 25 via the second integration circuit 33, the larger the silent discharge current (that is, the higher the ozone concentration), the more likely the base input of the transistor 2 is turned off. pulse transformer 3
On the other hand, when the detection output of the silent discharge current is small (that is, when the discharge is insufficient), the second transistor 25 does not turn on in a short time, and the comparator The output pulse width of 24 becomes large, and as a result, a large amount of power is supplied to the creeping discharge body 4.

Effects of the Invention As is clear from the above explanation, the ozone generation circuit of the present invention controls the energy supplied to the creeping discharge body in response to the detection output of the silent discharge current, so it can be used even in a humid atmosphere. can also easily start a discharge. In addition, drive pulses are applied at the most efficient phase within the period of damped oscillation formed by the secondary winding of the pulse transformer and the creeping discharge body to efficiently supply energy to the creeping discharge body. . Furthermore, by using a temperature-sensitive element or a voltage non-linear element in the silent discharge current detection circuit, it is possible to reduce the temperature dependence of the amount of oxidation generated and the dependence on the power supply voltage. It is extremely effective as an ozone generation circuit used in ozone deodorizers.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an ozone generation circuit according to one embodiment of the present invention, FIG. 2 is a diagram showing the configuration of an ozone generation circuit according to another embodiment of the present invention, and FIG. 3 is a diagram showing the configuration of an ozone generation circuit according to another embodiment of the present invention. FIG. 4 is a diagram showing an example of the silent discharge current detection circuit, FIG. 5 is a diagram showing another example of the silent discharge current detection circuit, and FIG. FIG. 7 is a diagram showing another embodiment of the secondary winding current detection circuit; FIG. 8 is a diagram showing an embodiment of the pulse generator. . 1...Pulse generator, 2...Transistor, 3...Pulse transformer, 4...
Creeping discharge body, 5...Silent discharge current detection circuit, 6
... Secondary winding current detection circuit, 7 ... Detection resistor, 8 ... High pass filter, 9 ...
...Integrator circuit, 10...Temperature sensing element or electrical appliance, 21...Differentiating circuit, 22...Capacitor, 23...Resistor, 24... ...Comparator, second transistor for 25, 30...
Switch element, 31...Primary winding, 32...
...Secondary winding, 33...Second integration circuit.

Claims (7)

[Claims] (1) A pulse generator, a transistor and a pulse transformer driven by the output of the pulse generator, a creeping discharge body connected to a secondary winding of the pulse transformer, and the creeping discharge body silently discharging. 1. An ozone generating circuit comprising: a detection circuit for detecting a silent discharge current generated at the time of the ozone generating circuit; and controlling an output pulse width of the pulse generator in accordance with the silent discharge current. (2) a pulse generator, a transistor and a pulse transformer driven by the output of the pulse generator, a creeping discharge body connected to the secondary winding of the pulse transformer, and a secondary winding current of the pulse transformer; and a detection circuit, and the output pulse generation timing of the pulse generator is synchronized with the current phase of damped oscillation formed by the secondary winding of the pulse transformer and the creeping discharge body. Ozone generation circuit. (3) A pulse generator, a transistor and a pulse transformer driven by the output of the pulse generator, a creeping discharge body connected to a secondary winding of the pulse transformer, and the creeping discharge body silently discharging. and a secondary winding current detection circuit of the pulse transformer. What is claimed is: 1. An ozone generating circuit that is synchronized with a current phase of a damped oscillation formed by a discharge body, and simultaneously controls an output pulse width of the pulse generator in response to the silent discharge current. (4) The silent discharge current detection circuit includes at least a resistor inserted into the path of the secondary winding current of the pulse transformer, and a high-pass filter for separating the silent discharge current component from the terminal voltage of the resistor. 4. The ozone generating circuit according to claim 1, further comprising: an integrator circuit that integrates the output of the high-pass filter. (5) The ozone generation circuit according to claim 4, wherein the output circuit of the integrating circuit includes a temperature sensing element, a voltage nonlinear element, or a temperature sensing element and a voltage nonlinear element simultaneously. (6) The secondary winding current detection circuit includes at least a zero cross detector inserted into a path of the secondary winding current of a pulse transformer, and a phase shifter that changes the phase of the output of the zero cross detector; 4. The ozone generating circuit according to claim 2, further comprising a frequency divider that divides the output of the phase shifter. (7) The pulse generator includes a rectangular generator, a differentiating circuit composed of a capacitor and a resistor that differentiates the output of the rectangular generator, and a comparator that discriminates the output of the differentiating circuit using a predetermined threshold. , a second transistor whose collector and emitter are connected to both ends of the resistor of the differentiating circuit, and an output corresponding to the silent discharge current component is transmitted to the second transistor via a switch element and a second integrating circuit. 4. The ozone generating circuit according to claim 1, wherein the ozone generating circuit is supplied to the base of a transistor.