JP4830169B2 - Electrostatic application power supply - Google Patents

Description

  The present invention relates to an electrostatic application power supply device used in an electrostatic application spray device for applying an electrostatic charge to sprayed agricultural chemicals or paints to reliably adhere these agricultural chemicals or paints to an adherend.

  2. Description of the Related Art Conventionally, a static electricity imparting type sprayer in which an electrode such as a high potential ring is disposed in front of a spray nozzle is provided. In this electrostatic application type sprayer, electric charges from the electrodes are applied to a spray liquid such as a chemical liquid sprayed from the spray nozzle and released into free space. For this reason, the adhesiveness to the agricultural crops, such as the chemical liquid atomized by the injection, becomes favorable, and the effects of pest control and sterilization are improved (for example, refer to Patent Document 1).

  By the way, since such a conventional electrostatic application type sprayer is generally used outdoors, a battery that is convenient to carry is used as a power supply for the electrostatic application, and the DC voltage of this battery is boosted to a high voltage. A method of applying continuously to the annular electrode or the like as an electrostatic application electrode in the vicinity of the spray nozzle is employed.

  Also, a first display element such as a light emitting diode is provided in order to notify the operator that the power supply voltage is being supplied from the battery by lighting, while a DC high voltage is applied to the electrostatic application electrode. In order to notify this by lighting, a second display element such as a light emitting diode is provided.

  Therefore, it is possible to notify the operator that the power supply voltage has been cut off or lowered, or that the DC high voltage of the electrostatic application electrode has been lowered, by turning off or turning on (dark light) close to turning off.

  FIG. 2 is a circuit diagram showing such a conventional electrostatic power supply device. This will be described. A battery 11 such as a dry battery or a secondary battery is connected in series with an issue diode 13 and a resistor 14 which are first display elements via a power switch 12.

  A step-up transformer 15 and a FET 16 (drain electrode, source electrode) as a switching element are connected in series to the battery 11 via a power switch 12. The gate of the FET 16 is connected to a pulse output terminal of an oscillation circuit 17 connected in series with the battery 11.

  Further, an LED control circuit 18 as a display control circuit is connected to the battery 11, and a control input terminal of the LED control circuit 18 is an FET 16 via a light emitting diode 19 which is a second display element and a time constant circuit 20. Connected to the gate.

  An electrostatic application electrode 22 is connected to the secondary winding of the step-up transformer 15 via a rectifier diode 21 as a rectifier.

  In such a conventional electrostatic application power supply device, when the power switch 12 is turned on, the voltage generated by the battery 11 is applied between the drain electrode and the source electrode of the FET 16 via the primary winding of the step-up transformer 15.

  On the other hand, the oscillation circuit 17 generates a switching pulse having a predetermined frequency, and the FET 16 is switched in response to the switching pulse.

  For this reason, the voltage applied from the battery 11 to the primary side winding of the step-up transformer 15 is interrupted by the FET 16, and a high voltage pulse is induced in the secondary side winding of the step-up transformer 15. Moreover, this high voltage pulse is rectified by the rectifier diode 21, becomes a DC high voltage of, for example, 15 to 20 kilovolts, and is applied to the electrostatic application electrode 22 arranged in front of the spray nozzle (not shown).

  Therefore, the spray particles of the chemical solution such as agricultural chemicals ejected from the spray nozzle are given an electric charge from the static electricity applying electrode 22, and the adhesion of the chemical solution to the leaves of the cultivated plant is good due to the given electric charge. Become. For this reason, the extermination effect or disinfection effect of the pest attached to this leaf etc. is heightened.

  On the other hand, when the power switch 12 is turned on, the battery 11 supplies a power supply voltage to the step-up transformer 15, the oscillation circuit 17, the LED control circuit 18, and the like, and this power supply state is the state of the light emitting diode 13 that is the first display element. Displayed by lighting.

  At this time, the light emitting diode 19 as the second display element blinks under the control of the LED control circuit 18. For this reason, it is displayed that a DC high voltage is applied to the electrostatic application electrode 22. On the other hand, the switching pulse output from the oscillation circuit 17 changes its duty when the electrostatic application electrode 22 is short-circuited to the ground, and the light emitting diode 19 is extinguished under the influence, and a high voltage is applied to the electrostatic application electrode 22. Display that it is not.

  Further, in the electrostatic spraying operation, the storage capacity of the battery 11 is gradually consumed, and finally the generated voltage is greatly reduced due to the drooping characteristic of the battery 11.

For this reason, the light emitting diode 13 for displaying the supply of the power supply voltage and the light emitting diode 19 for performing the electrostatic application display on the electrostatic application electrode are darkened. Thereby, the operator can recognize that the electrical storage capacity and electrostatic spraying capability of the battery 11 have decreased.
JP 2001-300362 A

  However, in the conventional electrostatic application power supply apparatus, when the light-emitting diodes 13 and 19 are turned off or are turned on close to extinguishing, the operator can change this state to the electrostatic application electrode. It may be misunderstood that the supply of high voltage to is stopped. In this case, there is a problem of electric shock if the hand or the like is touched carelessly.

  The present invention has been made paying attention to such conventional problems, when the voltage level of the electrostatic application electrode is reduced during the electrostatic spraying operation, and the electrostatic application effect can not be obtained, The operator turns off the light-emitting diode for power supply voltage display and / or the light-emitting diode for electrostatic application display, and cuts off the high voltage supply to the electrostatic application electrode, thereby turning off the light-emitting diode after each light-emitting diode is turned off. An object of the present invention is to provide a static electricity applying power supply device that can avoid an electric shock even if it touches the static electricity applying electrode.

In order to achieve the above object, an electrostatic application power supply device according to the present invention includes a battery, an oscillation circuit that operates using the battery as a power supply and outputs a pulse voltage, and a voltage generated by the battery. a switching element intermittently by the pulse voltage to be output is connected to the battery via the switching element, and a step-up transformer to induce a pulse voltage of a high voltage on the secondary side for boosting the primary voltage by the intermittent spray Provided in front of the nozzle injection port, connected to the secondary side of the step-up transformer, for applying an electrostatic charge to spray particles injected from the injection port , and supply of power supply voltage from the battery And a second display element that displays the switching operation of the switching element, and rectifies the high-voltage pulse voltage. A voltage reference value setting means for setting the power supply voltage when the first display element and the second display element are in a lighting state close to extinction as a reference value. And a power shut-off means for shutting off the supply of the power supply voltage from the battery to the step-up transformer when the power supply voltage falls below the set reference value.

  With this configuration, it is possible to cut off the high voltage supply to the electrostatic application electrode substantially in parallel with the turning-off of the light emitting diode for power supply voltage display and the light emitting diode for electrostatic application display. A high voltage is not applied to the application electrode, and even if an operator touches the electrostatic application electrode, there is no electric shock at all.

  In the electrostatic application power supply apparatus of the present invention, the voltage reference value setting means sets, as a reference value, a power supply voltage when the first display element and the second display element are in a lighting state close to extinction. When the power supply voltage is lower than the set reference value, the power supply means shuts off the supply of the power supply voltage from the battery. When the light emitting diode is turned off, the high voltage supply to the electrostatic application electrode is interrupted, and even if the operator touches the electrostatic application electrode, an electric shock can be avoided.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a circuit diagram illustrating a static electricity supply apparatus according to an embodiment of the present invention. In the figure, a battery 11 such as a dry battery or a secondary battery is connected in series with a series circuit of resistors 23 and 24 and a Zener diode 25 as voltage reference value setting means via a power switch 12.

  The negative input terminal of the operational amplifier 27 is connected to the connection point of the resistors 23 and 24 through the resistor 26, and the cathode of the Zener diode 25 is connected to the positive input terminal of the operational amplifier 27 via the resistor 28. Has been.

  The output terminal of the operational amplifier 27 is connected via the power switch 12 to the gate of an FET 29 serving as a power shut-off means placed in the middle of the power line L connected to the battery 11. The FET 29 has a source electrode and a drain electrode connected in the middle of the power supply line to turn on and off the power supply voltage supplied to the power supply line.

  In the battery 11, a series circuit of a primary side winding of the light emitting diode 13, the LED control circuit 18, the oscillation circuit 17, and the step-up transformer 15 and the FET 16 as a first display element is connected via the power switch 12 and the FET 29. These are connected in series as in the circuit diagram shown in FIG. In addition, an electrostatic application electrode 22 is connected to the secondary winding of the step-up transformer 15 via a rectifier diode 21.

  A light-emitting diode 19 as a second display element is connected between the LED control circuit 18 and the gate of the FET 16 via a time constant circuit 20. The light-emitting diode 19 is controlled under the control of the LED control circuit 18. Flashes. On the other hand, the switching pulse output from the oscillation circuit 17 changes its duty when the electrostatic application electrode 22 is short-circuited to the ground, and the light emitting diode 19 is extinguished under the influence, and a high voltage is applied to the electrostatic application electrode 22. Display that it is not.

  The resistors 23 and 24 function to detect a divided voltage value of the voltage generated by the battery 11, and the Zener diode 25 sets a power supply voltage when the light emitting diode 13 is in a lighting state close to extinction as a reference value. To function.

  As a result, the operational amplifier 27 detects the divided value of the actual power supply voltage with respect to the reference value. When the divided voltage value of the power supply voltage falls below the reference value, the gate voltage of the FET 29 is changed to suppress the flow of electrons between the source electrode and the drain electrode, and the light emitting diodes 13, 19 and LED from the battery 11 are suppressed. The supply of power supply voltage to the control circuit 18, the oscillation circuit 17, the step-up transformer 15 and the like can be cut off.

  Next, the operation of the electrostatic application power supply device having the above-described configuration will be described with reference to the drawings.

  When spraying agricultural chemicals using the electrostatic application spraying device, first, the chemical solution is pumped from the chemical solution tank to the spray nozzle by a pump (not shown). For this reason, a high-pressure chemical solution is ejected from the spray nozzle in an atomized state.

  On the other hand, when the power switch 12 is turned on in parallel with the injection of the chemical solution from the injection nozzle, the power supply voltage generated by the battery 11 is divided by the resistors 23 and 24 and the negative of the operational amplifier 27 is connected via the resistor 26. It is input to the side input terminal.

  In parallel with this, the power supply voltage is input to the positive input terminal of the operational amplifier 27 via the resistor 28. The voltage input to the positive input terminal is set to the reference value by the Zener diode 25.

  When the power is turned on, the storage capacity of the battery 11 is sufficiently large and the power supply voltage is high. Therefore, the operational amplifier 27 determines that the power supply voltage exceeds the reference value and triggers the gate of the FET 29. For this reason, the power supply voltage is supplied to the power supply line L through the drain electrode and the source electrode of the FET 29.

  For this reason, a current flows through the resistor 13 through the resistor 14, and the LED 13 is lit. The oscillation circuit 17 oscillates and outputs a switching pulse (voltage pulse) of 11 kHz, for example. Further, a power supply voltage is applied to the FET 16 as a switching element via the primary winding of the step-up transformer 15.

  The FET 16 receives the voltage pulse at the gate electrode, and interrupts the voltage applied between the drain electrode and the source electrode. Due to this intermittent operation, the voltage applied to the primary winding of the step-up transformer 15 is also intermittent, so that a high voltage pulse of the same frequency boosted to the secondary winding of the step-up transformer 15 is induced.

  The high voltage pulse is rectified to a DC high voltage through the rectifier diode 21 and then supplied to the electrostatic application electrode 22. For this reason, the chemical liquid ejected from the ejection nozzle is given an electric charge by the electrostatic application electrode 22 arranged in front of the ejection nozzle.

  In this way, the sprayed chemical solution to which the electric charge is applied has improved adhesion to a cultivated plant having a ground potential, for example, a leaf of an agricultural crop, and can perform extermination and sterilization of a pest attached to the leaf.

  On the other hand, the voltage pulse of the oscillation circuit 17 is also applied to the cathode of the light emitting diode 19 which is the second display element via the time constant circuit 20 and is lit according to the control conditions determined by the LED control circuit 18. That is, the light emitting diode 19 is turned on when a high DC voltage of a predetermined level or higher is applied to the electrostatic application electrode 22 and electrostatic spraying is normally performed.

  By the way, the battery 11 such as the dry battery or the secondary battery consumes the stored charge with time of use, and the generated voltage gradually decreases. For this reason, the voltage induced on the secondary side of the step-up transformer 15 also decreases, and at the same time, the electrostatic energy supplied to the spray chemical liquid injected from the injection nozzle decreases or becomes unstable. Thereby, the adhesion amount of the chemical | medical solution with respect to agricultural products will become uneven or inadequate.

  Further, as the power supply voltage of the battery 11 decreases, the light emitting diodes 13 and 19 become darker as the applied voltage gradually decreases. However, even in this state, the electrostatic application electrode 22 still maintains a high voltage (for example, 3.8 kilovolts below the normal 15 to 20 kilovolts).

  Therefore, according to the present invention, the output of the operational amplifier 27 opens the drain electrode and the source electrode of the FET 29 at the timing when the light emitting diodes 13 and 19 are turned off or almost turned on.

  By the opening between the drain electrode and the source electrode of the FET 29, power supply from the battery 11 to the light emitting diode 13, the LED control circuit 18, the oscillation circuit 17, and the step-up transformer 15 is cut off all at once.

  Therefore, the operator can determine whether the high voltage supply to the electrostatic application electrode 22 is stopped by turning off both the light emitting diodes 13 and 19, and the operator may touch the electrostatic application electrode 22 with his / her hand. However, there is no electric shock.

  As a result, when the light-emitting diodes 13 and 19 become dark and the lighting state cannot be confirmed with the brightness of the surroundings as before, the situation where an electric shock is caused by accidentally touching the electrostatic application electrode 22, It can be avoided in advance.

  Moreover, the replacement of the battery 11 is urged by turning off the light-emitting diodes 13 and 19 accompanied by the simultaneous interruption of the power supply.

  As described above, in the present embodiment, the voltage reference value setting unit 25 uses the power supply voltage when the first display element 13 and the second display element 19 are in a lighting state close to extinction as a reference value. When the power supply voltage is lower than the set reference value, the power supply cutoff means 29 is configured to cut off the supply of the power supply voltage from the battery 11. Almost simultaneously with the extinction of the light emitting diode 13 and the light emitting diode 19 for the electrostatic application display, the high voltage supply to the electrostatic application electrode 22 can be cut off. Therefore, a high voltage is applied to the electrostatic application electrode 22 thereafter. In other words, even if an operator touches the electrostatic application electrode 22 with his / her hand, there is no electric shock.

  The electrostatic application power supply device according to the present invention cuts off the high voltage supply to the electrostatic application electrode substantially in parallel with the light-emitting diode for power supply voltage supply display and the light-emitting diode for electrostatic application display off. Therefore, after that, no high voltage is applied to the electrostatic application electrode, and even if an operator touches the electrostatic application electrode, there is no effect of electric shock. It is useful for an electrostatic application power supply device used in an electrostatic application spraying device for reliably attaching these agricultural chemicals and paints to an adherend by applying static electricity to the above.

It is a circuit diagram which shows the static electricity provision power supply device by embodiment of this invention. It is a circuit diagram which shows the conventional electrostatic provision power supply device.

Explanation of symbols

11 Battery 12 Power switch 13 Light emitting diode (first display element)
15 Step-up transformer 16 FET (switching element)
17 Oscillating circuit 18 LED control circuit 19 Light emitting diode (second display element)
20 Time constant circuit 21 Diode for rectification 22 Electrostatic application electrode 23, 24, 26, 28 Resistance 27 Operational amplifier 29 FET

Claims (1)

A battery, an oscillation circuit that operates using the battery as a power source, and outputs a pulse voltage; a voltage generated by the battery; a switching element that is intermittently generated by the pulse voltage output by the oscillation circuit; and the switching element via the switching element A step-up transformer that is connected to a battery and boosts the primary side voltage by the intermittent and induces a high-voltage pulse voltage on the secondary side; and is provided in front of an injection port of the spray nozzle, on the secondary side of the step-up transformer An electrostatic application electrode that is connected and applies an electric charge to the spray particles injected from the injection port; and a first display element that displays supply of a power supply voltage from the battery;
A second display element that displays a switching operation of the switching element, wherein the high-voltage pulse voltage is rectified and applied to an electrostatic application electrode. Voltage reference value setting means for setting, as a reference value, a power supply voltage when the display element and the second display element are in a lighting state close to extinction, and when the power supply voltage falls below the set reference value, from the battery An electrostatic application power supply device comprising: a power supply cutoff means for cutting off supply of power supply voltage to the step-up transformer .

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