JP2853028B2 - High voltage power supply cutoff circuit for static eliminator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high voltage power supply for a static eliminator in which a voltage from a commercial power supply is boosted by a high voltage transformer and applied to the static eliminator. To a breaking circuit.

[0002]

2. Description of the Related Art A conventional shut-off circuit of this type is disclosed in Japanese Utility Model Laid-Open No. 56-112899. In this conventional example, a weak spark (discharge noise) is detected by an impedance connected to a secondary-side ground terminal of a high-voltage transformer, the detected weak spark is rectified by a rectifier circuit, integrated by a capacitor, and further fixed. After applying a constant voltage with a voltage element, input it to the gate of the semiconductor control rectifier,
The relay is turned on / off by this semiconductor control rectifier to connect / disconnect the primary side of the high voltage transformer.

[0003]

However, according to this conventional example, the detected weak spark is rectified by a rectifier circuit, integrated, and further converted to a constant voltage by a constant voltage element and input to the gate of the semiconductor control rectifier. Therefore, there is a problem that a considerable time delay occurs from the occurrence of the discharge to the interruption of the primary side of the high voltage transformer due to the operation time required during the operation.

An object of the present invention is to provide a shut-off circuit for a high-voltage power supply for a static eliminator, which can shorten the time from the occurrence of discharge to the shut-down of the primary side of a high-voltage transformer.

[0005]

According to the present invention, a discharge pulse (discharge noise) is generated in a high voltage power supply for a static eliminator in which a voltage from a commercial power supply is boosted by a high voltage transformer 4 and applied to the static eliminator.
A pulse transformer 9 connected to the secondary side of a high-voltage transformer, a differentiating circuit 16 for differentiating a discharge pulse detected by the pulse transformer, and a switching transistor for directly inputting the differentiated pulse to a gate. 17 and a relay 18 which is turned on / off by the switching transistor 17 to connect / disconnect between the commercial power supply and the primary side of the high voltage transformer.

That is, according to the present invention, since a pulse generated by a discharge is boosted and detected by a pulse transformer and differentiated and directly input to the switching transistor before the discharge pulse completely rises, no time delay occurs.

The differentiating circuit, the switching transistor, and the relay are preferably mounted on the same printed circuit board together with a rectifying circuit for rectifying an AC voltage from a commercial power supply so that the DC voltage rectified by the rectifying circuit is supplied.

[0008]

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

FIG. 1 mainly shows a circuit configuration of a high voltage power supply for a static eliminator, and FIG. 2 shows a configuration of a cutoff circuit connected thereto. 1 is connected to a 100 V or 200 V commercial AC power supply (having a frequency of 50 Hz or 60 Hz), and when the power switch 1 is turned on, the high voltage power supply for the static eliminator is 100 V or 200 V.
The AC voltage of V is supplied to the noise filter 2 to remove noise.

The output terminal on the high voltage side of the two high and low output terminals of the noise filter 2 is connected to a high voltage transformer 4 via a voltage switch 3 for switching between 100 V and 200 V.
Are connected to the 100V input tap and 200V input tap on the primary side, and the output terminal on the low voltage side is connected to the cutoff circuit 5 according to the present invention.

The secondary side of the high voltage transformer 4 has three coils 6
Each coil is provided with a tap for 50 Hz and a tap for 60 Hz. The first coil 6a of the three coils is connected to a high-voltage output terminal 7 for connection to a static eliminator (not shown). The 50 Hz tap and the 60 Hz tap of the first coil 6a are frequency switched. Is connected to one input tap of the pulse transformer 9 via the switch 8a. The 50 Hz tap and the 60 Hz tap of the second coil 6 b are connected to the other input tap of the pulse transformer 9 via the frequency switch 8 b. 50H of the third coil 6c
The tap for z and the tap for 60 Hz are connected to the output indicator 10 via the frequency switch 8c. The frequency switching switches 8a, 8b, 8c are interlocking switches, and switch according to whether the commercial AC power supply is at 50 Hz or 60 Hz.

The pulse transformer 9 detects when a discharge pulse is generated on the secondary side of the high-voltage transformer 4. The detected discharge pulse is boosted and output from the secondary side of the pulse transformer 9. You.

Next, the configuration of the cutoff circuit 5 of FIG. 2 will be described. The entire shutoff circuit 5 shown in FIG. 2 is mounted on a single printed circuit board 11, and is connected to the high voltage power supply for the static eliminator shown in FIG. 1 by connection terminals provided on the printed circuit board 11. The connection terminals include an AC power supply common connection terminal AC-COM and an AC power supply 100 V connection terminal AC-1.
00, an AC power supply 200V connection terminal AC-200, high-voltage transformer primary side connection terminals S1 and S2, pulse transformer connection terminals P1 and P2, and abnormal lamp connection terminals A1 and A2.

Looking at the connection between these connection terminals and the outside of the cutoff circuit 5, the AC power supply common connection terminal AC-COM is connected to the low-voltage output terminal of the noise filter 2 and the AC power supply 100.
The V connection terminal AC-100 is connected to the voltage switch 10
0V side terminal, AC power supply 200V connection terminal AC-200
Are connected to the 200 V side terminals of the voltage switch 3 respectively. High voltage transformer primary side connection terminals S1, S2
Is connected between the low-voltage output terminal of the noise filter 2 and the low-voltage input tap on the primary side of the high-voltage transformer 4. The pulse transformer connection terminals P1 and P2 are connected to the secondary side of the pulse transformer 9. Lamp connection terminal A1
The abnormality notification lamp 12 is connected to A2.

In the shutoff circuit 5, that is, on the printed circuit board 11, an AC power supply common connection terminal AC-COM, an AC power supply 100V connection terminal AC-100, an AC power supply 200V
The rectifier circuit 13 is connected to the connection terminal AC-200, and the cutoff circuit 5 is driven by a DC voltage obtained by rectifying an AC voltage.

P1 of the pulse transformer connection terminals P1 and P2 is connected to an output terminal of a rectifier circuit 13, and P2 is connected to a differentiator 16 including a capacitor 14 and a variable resistor 15. The output terminal of the differentiating circuit 16 is connected to the gate of a triac 17, which is a switching transistor. One electrode of the triac 17 is a rectifier circuit 1
3 and the other electrode is connected to the coil 19 of the relay 18. When the triac 17 is turned on, a direct current flows from the rectifier circuit 13 to open the relay contact 20 of the coil 19. This relay contact 20
The high-voltage transformer is connected between the primary connection terminals S1 and S2 and is normally closed.
And the primary side of the high-voltage transformer 4 is brought into conduction.
When it opens, it shuts off between them.

In FIG. 1, reference numeral 21 denotes a static elimination notification lamp connected to the primary side of the high voltage transformer 4. A thyristor may be used as a switching transistor instead of a triac.

According to the configuration described above, in a normal state, the relay contact 20 is closed, so that an AC voltage of 100 V or 200 V from the commercial AC power supply is applied to the primary side of the high-voltage transformer 4 via the noise filter 2. The high voltage is supplied to the static eliminator connected to the secondary side high voltage output terminal 7 and supplied. In this case, the charge removal notification lamp 21 is turned on.

When a discharge pulse (discharge noise) is generated on the secondary side of the high voltage transformer 4, the discharge pulse is detected by the pulse transformer 9, and the detected discharge pulse is boosted from the secondary side of the pulse transformer 9. Is output. This discharge pulse is differentiated by the differentiating circuit 16 and the triac 17
Is directly input as a trigger pulse to the gate. Since the trigger pulse is directly input to the gate of the triac 17 before the discharge pulse completely rises, no time delay occurs.

When the triac 17 is turned on, the relay 18 is turned on and the relay contact 20 is opened, so that the connection between the noise filter 2 and the primary side of the high-voltage transformer 4 is cut off, and the high voltage is applied to the static eliminator. Stop. In this case, the abnormality notification lamp 12 is turned on.

[0021]

As described above, according to the present invention,
Since the pulse generated by the discharge is boosted and detected by the pulse transformer, differentiated and directly input to the switching transistor before the discharge pulse completely rises, the relay is turned on by this switching transistor and the primary side of the high voltage transformer is cut off. There is no time delay from the generation of the discharge pulse to the interruption, unlike the related art, and the application of the high voltage to the static eliminator can be immediately stopped at the moment when the discharge occurs.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram mainly of a high voltage power supply for a static eliminator.

FIG. 2 is an electric circuit diagram showing an example of a shut-off circuit of the present invention connected to the high-voltage power supply for the static eliminator of FIG. 1;

[Explanation of symbols]

 Reference Signs List 4 high voltage transformer 5 cutoff circuit 9 pulse transformer 11 printed circuit board 13 rectifier circuit 16 differentiator circuit 17 triac 18 relay

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02H 3/08-3/52 H05F 1/00-3/06 H02H 7/04

Claims (2)

(57) [Claims] 1. A high-voltage power supply for a static eliminator, which boosts a voltage from a commercial power supply with a high-voltage transformer and applies the boosted voltage to a static eliminator, comprising: a pulse transformer connected to a secondary side of the high-voltage transformer for detecting a discharge pulse; A differentiating circuit for differentiating a discharge pulse detected by the pulse transformer, a switching transistor for directly inputting the differentiated pulse to a gate, and an ON / OFF switch by the switching transistor.
A high voltage power supply cutoff circuit for a static eliminator, comprising: a relay that is turned off to connect and disconnect between the commercial power supply and a primary side of the high voltage transformer. 2. A differentiating circuit, a switching transistor, and a relay are mounted on the same printed circuit board together with a rectifier circuit for rectifying an AC voltage from a commercial power supply, and supplied with a DC voltage rectified by the rectifier circuit. Claim 1
The high voltage power supply cutoff circuit for a static eliminator according to the above description.