Power supply unit and static eliminator

Patent metadata

Field	Value
Publication number	US-10148193-B2
Application number	US-201715810200-A
Country	US
Kind code	B2
Filing date	Nov 13, 2017
Priority date	May 26, 2015
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

A power supply unit includes a transformer including a primary winding that receives an alternating-current voltage and a secondary winding including a first end electrically connected to ground, a positive-side rectification circuit including a diode electrically connected to a second end of the secondary winding, an anode of which is electrically connected to the second end, and a cathode of which is electrically connected to a positive-side output terminal, a negative-side rectification circuit including a diode electrically connected to the second end of the secondary winding, a cathode of which is electrically connected to the second end, and an anode of which is electrically connected to a negative-side output terminal, and a capacitor provided on a path from a node between the second end of the secondary winding and the positive-side rectification circuit and the negative-side rectification circuit to the ground through the secondary winding.

First claim

What is claimed is:

1. A power supply unit comprising:
a transformer including a primary winding that receives an alternating-current voltage and a secondary winding including a first end that is electrically connected to ground;
a first rectification circuit including a first diode that is electrically connected to a second end of the secondary winding, an anode of which is electrically connected to the second end, and a cathode of which is electrically connected to a positive-side output terminal;
a second rectification circuit including a second diode that is electrically connected to the second end of the secondary winding, a cathode of which is electrically connected to the second end, and an anode of which is electrically connected to a negative-side output terminal; and
a capacitor connected in series on a path extending from a node between the second end of the secondary winding and the first rectification circuit and the second rectification circuit to the ground through the secondary winding.

2. The power supply unit according to claim 1 , wherein the capacitor is provided between the secondary winding and the ground.

3. The power supply unit according to claim 1 , wherein the capacitor is provided between the node and the secondary winding.

4. The power supply unit according to claim 1 , further comprising:
a first resistive voltage divider circuit electrically connected in parallel to the capacitor.

5. The power supply unit according to claim 1 , wherein
the first rectification circuit includes a first smoothing capacitor electrically connected between the cathode of the first diode and the ground; and
the second rectification circuit includes a second smoothing capacitor electrically connected between the anode of the second diode and the ground.

6. The power supply unit according to claim 5 , further comprising:
a second resistive voltage divider circuit electrically connected in parallel to the first smoothing capacitor; and
a third resistive voltage divider circuit electrically connected in parallel to the second smoothing capacitor.

7. The power supply unit according to claim 1 , wherein
the transformer includes a tertiary winding; and
the power supply unit includes a detection circuit that detects voltage occurring at the tertiary winding.

8. The power supply unit according to claim 1 , wherein
the first rectification circuit includes a plurality of first rectification circuits and the second rectification circuit includes a plurality of second rectification circuits;
the positive-side output terminal includes a plurality of positive-side output terminals and the negative-side output terminal includes a plurality of negative-side output terminals;
the transformer includes a plurality of secondary windings; and
the second end of each of the plurality of secondary windings is electrically connected to the positive-side output terminal and the negative-side output terminal via the first rectification circuit and the second rectification circuit.

9. A static eliminator comprising:
the power supply unit according to claim 1 ;
a positive ion generator electrically connected to the positive-side output terminal; and
a negative ion generator electrically connected to the negative-side output terminal.

10. The static eliminator according to claim 9 , wherein each of the positive ion generator and the negative ion generator is a needle discharge electrode.

11. The static eliminator according to claim 9 , wherein the capacitor sets absolute values of currents applied to the positive ion generator and the negative ion generator to be equal or substantially equal.

12. The static eliminator according to claim 9 , wherein an amount of ions generated in the positive ion generator is equal or substantially equal to an amount of ions generated in the negative ion generator.

13. A load apparatus comprising:
the power supply unit according to claim 1 ;
at least one first resistive load connected to the positive-side output terminal; and
at least one second resistive load electrically connected to the negative-side output terminal.

14. The power supply unit according to claim 1 , wherein the transformer is included in a plurality of transformers with secondary windings that are connected in series.

15. The power supply unit according to claim 14 , wherein a capacitor is provided between each adjacent pair of the secondary windings of the plurality of capacitors.

16. The power supply unit according to claim 1 , wherein each of the first rectification circuit and the second rectification circuit is a Cockcroft circuit.

17. A power supply unit comprising:
a first positive and negative output circuit; and
a second positive and negative output circuit; wherein
each of the first positive and negative output circuit and the second positive and negative output circuit includes:
a positive-side output terminal and a negative-side output terminal;
a transformer including a primary winding that receives an alternating-current voltage and a secondary winding including a first end that is electrically connected to ground;
a first rectification circuit including a first diode which is electrically connected to a second end of the secondary winding, an anode of which is electrically connected to the second end, and a cathode of which is electrically connected to the positive-side output terminal;
a second rectification circuit including a second diode which is electrically connected to the second end of the secondary winding, a cathode of which is electrically connected to the second end, and an anode of which is electrically connected to the negative-side output terminal; and
a capacitor provided on a path from a node between the second end of the secondary winding and the first rectification circuit and the second rectification circuit to the ground through the secondary winding;

the positive-side output terminal of the first positive and negative output circuit is electrically connected to the negative-side output terminal of the second positive and negative output circuit via a first resistor and a second resistor;
the negative-side output terminal of the first positive and negative output circuit is electrically connected to the positive-side output terminal of the second positive and negative output circuit via a third resistor and a fourth resistor;
a node between the first resistor and the second resistor is electrically connected to a first positive and negative output terminal; and
a node between the third resistor and the fourth resistor is electrically connected to a second positive and negative output terminal.

18. A static eliminator comprising:
the power supply unit according to claim 17 ; and
ion generators electrically connected to the first positive and negative output terminal and the second positive and negative output terminal.

19. The power supply unit according to claim 17 , wherein each of the first positive and negative output circuit and the second positive and negative output circuit is operated with a cycle of about 0 seconds to about 0.2 seconds.

Assignees

• Murata Manufacturing Co

Inventors

• Kurokawa Takashi

Classifications

• H01T23/00

  Apparatus for generating ions to be introduced into non-enclosed gases, e.g. into the atmosphere · CPC title

• H02M7/062 Primary

  Avoiding or suppressing excessive transient voltages or currents · CPC title

• H05F3/04

  by means of spark gaps or other discharge devices (devices providing for corona discharge per se H01T19/00) · CPC title

• H05F3/06 Primary

  by means of ionising radiation · CPC title