JP4354979B2 - Static eliminator - Google Patents

Description

  The present invention relates to a static eliminator that applies a high-frequency AC voltage from a high-voltage transformer to a discharge electrode and discharges it to and from a ground electrode to generate positive and negative ions, and particularly flows from the ground electrode to the ground by discharge. The present invention relates to a static eliminator that monitors ground current and issues an alarm or the like.

  As described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-319358), the present applicant connects a capacitor element between an earth electrode (ground electrode) and the ground, and the ground current due to the discharge is There is provided a static eliminator configured to flow to the ground through a capacitor element, feed back the ground current to the high frequency power supply side to achieve a static neutralization balance, and display that a high voltage is generated.

On the other hand, in Patent Document 2 (Japanese Patent Laid-Open No. 7-143660), a current flowing between one end of the secondary side of the step-up transformer and the ground is detected, and an insulation breakdown or abnormal discharge is warned when the current exceeds a certain value. A safety device for a static eliminator is disclosed.
JP 2004-319358 A Japanese Patent Laid-Open No. 7-143660

  An object of the present invention is to provide a static eliminator that can be stably performed with little influence of external noise when alarming a decrease in static eliminator performance or a discharge stop, unlike those of Patent Documents 1 and 2. It is in.

The present invention relates to a rectifier circuit that rectifies a high-frequency AC ground current flowing from a ground electrode to a ground in a static eliminator that applies a high-frequency alternating current high voltage from a high-voltage transformer to a discharge electrode and discharges the ground electrode. A comparator that compares the half-wave voltage after rectification with a reference voltage, and a photocoupler that outputs an alarm signal by being turned on and off by the output of the comparator are provided.
A light emitting element that is turned on / off by an output of the comparator can be provided.

  According to the present invention, the ground current of the high-frequency alternating current flowing from the ground electrode to the ground is rectified, the rectified half-wave voltage and the reference voltage are compared by the comparator, and the photocoupler is turned on / off by the output of the comparator. Since the alarm signal is output, that is, the ground current is detected at a high frequency and compared with the threshold value, it is possible to stably alarm the deterioration of the static elimination performance or the stoppage of discharge with little influence of external noise.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, which comprises an electrode part A, a high-frequency and high-voltage power supply part B, and an alarm control part C.
The electrode section A showing the schematic cross-sectional structure is provided with a cylindrical ground electrode 3 on the inner peripheral surface of the nozzle 1 with respect to the needle-like discharge electrode 2 installed in the center of the nozzle 1 and this ground electrode. 3 is provided with an insulating material 4 made of resin, and a high-frequency AC high voltage is applied to the discharge electrode 2 from the high-frequency high-voltage power source B, and the insulating material 4 is interposed between the discharge electrode 2 and the ground electrode 3. By generating corona discharge with an electrostatic capacity interposed, positive and negative ions are ejected from the nozzle 1 together with air.

  The high-frequency high-voltage power supply unit B is connected to the external DC power source 6a of the connector 5 and grounded to the ground terminal 6b, so that, for example, a + 24V DC power supply voltage is supplied. When it is turned on, it is applied to the high-frequency self-excited oscillation circuit 9 via the regulator 8 and oscillates, so that a high-frequency AC high voltage is generated on the secondary side of the high-voltage transformer 10. The high frequency AC high voltage is applied to the discharge electrode 2 via the capacitor 11.

  An oscillation on / off signal is input to the regulator 8 from the signal input terminal 12 of the connector 5. The oscillation on / off signal is, for example, a signal from a sensor that detects the presence or absence of air supply to the nozzle 1. When the air supply to the nozzle 1 is stopped, the oscillation on / off signal is supplied to the high-frequency self-excited oscillation circuit 9. The power supply is cut off by the regulator 8, and the high-frequency self-excited oscillation circuit 9 is automatically turned off.

  A neutralization balance circuit 13 is connected to one end of the secondary side of the high-voltage transformer 10, and a current generated on the secondary side during discharge is detected by the neutralization balance circuit 13 and fed back to the high-frequency self-excited oscillation circuit 9. By automatically adjusting the positive and negative components of the excitation oscillation, a positive and negative charge removal balance can be achieved.

  The alarm control unit C connects a capacitor 14 between the ground electrode 3 and the ground, and rectifies a high-frequency AC ground current flowing to the ground through the capacitor 14 by a rectifier circuit 16 using a diode 15 to generate a positive component ( Or a negative component) half-wave voltage, which is compared with a reference voltage by the comparator 17. The output of the comparator 17 is input directly to one transistor 18 of the two transistors 18 and 19 and inverted by the inverter 20 to the other transistor 19. The light emitting elements 21 and 22 having different emission colors are connected to the transistors 18 and 19, respectively, and the light emitting element 23a of the photocoupler 23 is connected to one transistor 18. In this example, the light emitting element 21 is green and the light emitting element 22 is red.

  When the half-wave voltage rectified by the rectifier circuit 16 exceeds the reference voltage, the output of the comparator 17 is “H”, one transistor 18 is turned on, the green light emitting element 21 is lit, and the electrode It displays that the discharge in part A is normal. At this time, the other transistor 19 is off, the red light emitting element 22 is extinguished, the light emitting element 23a of the photocoupler 23 is off, and no alarm signal is generated from the light receiving element 23b.

  On the other hand, when the half-wave voltage rectified by the rectifier circuit 16 is less than the reference voltage, the output of the comparator 17 is “L”, the other transistor 19 is turned on, and the red light emitting element 22 is turned on, It displays that the discharge at the electrode part A is abnormal. At this time, one of the transistors 18 is off, the green light emitting element 21 is turned off, and the light emitting element 23a of the photocoupler 23 is turned on to generate an alarm signal from the light receiving element 23b. This alarm signal is output from the signal output terminal 24 of the connector 5 to the outside.

In the circuit diagram of one Example of this invention, a power supply part shows an outline sectional structure.

Explanation of symbols

A electrode part B high frequency high voltage power supply part C alarm control part 1 nozzle 2 discharge electrode 3 ground electrode 4 insulating material 5 connector 6a power supply terminal 6b ground terminal 7 switch 8 regulator 9 high frequency self-excited oscillation circuit 10 high voltage transformer 11 capacitor 12 signal input terminal 13 Static elimination balance circuit 14 Capacitor 15 Diode 16 Rectifier circuit 17 Comparator 18/19 Transistor 20 Inverter 21/22 Light emitting element 23 Photocoupler 23a Light emitting element 23b Light receiving element 24 Signal output terminal

Claims (2)

  In a static eliminator that applies a high-frequency AC high voltage from a high-voltage transformer to a discharge electrode and discharges it between the ground electrode, a rectifier circuit that rectifies a high-frequency AC ground current flowing from the ground electrode to the ground, A static eliminator comprising: a comparator that compares a half-wave voltage with a reference voltage; and a photocoupler that outputs an alarm signal by being turned on and off by the output of the comparator.   2. The static eliminator according to claim 1, further comprising a light emitting element that is turned on / off by an output of the comparator.

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