JPS59122374A - Rush current suppressing circuit - Google Patents

Abstract

PURPOSE:To prevent the decrease of a power source voltage due to a protective resistor by shortening part of the connecting pin of a connector and shortcircuiting the protective resistor after stabilizing a power source. CONSTITUTION:Power supply is performed through a connector 11. The DC of a rectifier 3 is supplied to a load 9 through connecting pin terminals 12-1, 13-1, and a protective resistor 5 while charging a capacitor 6. When the connector 11-2 is inserted deeply into the connector 11-1, the terminal 12-2 is connected to the terminal 13-2. A protective resistor 5 is shortcircuited by a shortcircuiting piece 14, the DC of the rectifier 3 charged the capacitor directly through the terminals 12-2, 13-2, and this charging voltage is applied to the load 9.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to an inrush current suppression circuit when a panel of an electronic device having a power supply device of a capacitor input type rectifier circuit is inserted.

(b) Prior art and problems Conventionally, in order to suppress the inrush current when the power is turned on for electronic equipment that has a capacitor input type rectifying and smoothing circuit (hereinafter referred to as a capacitor input type circuit) power supply, a protective resistor is inserted in the main line. When the supply current reaches a steady state, the protective resistor is short-circuited.

However, depending on the state of use of the electronic device, it may be necessary to remove or insert the panel while the electronic device is in operation. In this case, when the panel is inserted, the inrush current not only damages the power supply side, but also the inrush current flows through the panel, which may damage circuit components or damage the panel. For this reason, the panel must also be equipped with an inrush current suppression circuit. For this reason, there is a need for an inrush current suppression circuit that can supply a steady voltage to the panel by short-circuiting the protective resistor after the panel is inserted.

FIG. 1 shows a conventional inrush current suppression circuit for a power supply circuit of an electronic device.

In FIG. 1, when a switch 1 is turned on, an AC power supply 2 is rectified into DC by a rectifier 3, and the DC is passed through a fuse 4. A capacitor 6 is charged via a resistor 5. In this case, a large inrush current flows through the capacitor 6 to charge the capacitor 6, which becomes the main line current, and a protective resistor 5 is inserted to prevent damage to the rectifier 3 or a drop in the input supply voltage. When the charge of the capacitor 6 reaches a predetermined value, a detector 7 detects a predetermined voltage, shorts the protective resistor 5 at a contact 8, and supplies a predetermined voltage to a load 9, which is a panel of an electronic device.

The above method uses the entire panel of an electronic device as one load to suppress inrush current, and since there is no sampling circuit for each individual panel, if a panel is inserted while it is moving, the inrush current will cause rectification as described above. It may damage circuits, etc.

(c) Purpose of the Invention In order to solve the above-mentioned problems, the present invention includes an inrush current suppression circuit in each panel of an electronic device or each device to prevent a drop in power supply voltage due to a protective resistor after the power is turned on. The purpose is to provide an inrush current suppression circuit.

(d) Structure of the Invention In order to achieve the above-mentioned object, the present invention provides, when inserting a panel into an electronic device, an intrusion connection pin is provided at the time of insertion of the panel, and the short-circuit connection pin is made shorter than other connection pins. (b) The short-circuit connecting pin is connected after the circuit of the panel is connected to the electronic device via the connector, and the acquisition resistor and the capacitor form a series connection when the panel is inserted. The protective resistor is then short-circuited using the short-circuit connecting pin, and the charging voltage of the capacitor is supplied to the panel.

(e) Examples of the invention Hereinafter, the present invention will be explained based on the drawings.

FIG. 2 shows an embodiment of the present invention, the outline of which is as follows. As explained earlier with reference to Fig. 1, in the conventional example, inrush current was suppressed for each panel of an electronic device or for the device all at once.
In this embodiment, since an inrush current suppression circuit is provided for each panel, no trouble will occur due to inrush current even if each panel is removed or inserted at any time. To achieve this, a part of the connecting pin terminal of the panel connector is shortened, and a protective resistor shorting piece is connected to this connecting piece, so that when the connector is connected, the connection of this terminal is delayed from the other pin terminals. The protection resistor is short-circuited later than other circuits. This allows stable power to be supplied to the load.

In FIG. 2, 2, 3, 5, 6.9 indicate the same members having the same functions as those in FIG. In the figure, an AC power supply 2 is rectified into DC by a rectifier 3, and the DC component is supplied to each panel, for example, 10-1.

This power supply is performed via connector 1. in this case,
Connector 1 consists of connector 1-1 on the power supply side and connector 1-2 on the panel side. First, connect the power supply side connector 1
Short-circuit connecting pin terminals 12-1 and 12-2 of 1-1, and connect connecting pin terminals 13-2 of connector 11-2 on the panel side to 13-1.13-3 to 13-n. If you keep the connection pins short so that the connection time is delayed, then when you insert connector 11-2 into connector 11-1 and connect it, first connect the connection pin terminals 12-1 and 13-1.
1 and 12-3 and 13-3. ...12-n and 13-n
are connected. In this state, the direct current (2o) of the rectifier circuit 3 passes through the connection pin terminals 12-1, 13-1 and the protective resistor 5, charges the capacitor 6, and supplies the load 9 with a current (2o). By the above charging, the inrush current to the load 9 due to the connection between the connection bins 12-1 and 13-1 is suppressed. -2 is connected, the protective resistor 5 is short-circuited by the shorting piece 14, and 1° is connected to the connecting pin terminal 12-2.
．． The capacitor 6 is directly charged via the capacitor 13-2, and this charging pressure is applied to the load 9.

Here, in the connection of the connectors 11-1 and 11-2, the connection with the connection pin terminal 12-1.13-1 is made, and then the connection of the connection pin terminal 12-2.13-2 is made.
During this time, the connection time difference between the two is the protective resistor 5 and the capacitor 6.
Generally, connecting the connectors 11-1 and 11-2 manually is slower, so the inrush current can be suppressed by the time difference between the manual operations.

Although the embodiments of the present invention have been described above with respect to a power source for a rectifier circuit, they can also be applied to a case where a battery or the like is used.

(f) As described in detail of the invention, in the conventional example, a protective resistor is connected in series with the power supply to suppress inrush current, which has the disadvantage that the power supply's voltage decreases due to the protective resistor. In this case, some of the connecting pins of the connector are shortened and the protective resistor is short-circuited after the power supply stabilizes to prevent the power supply voltage from dropping.

[Brief explanation of drawings]

FIG. 1 shows a conventional rush current suppression circuit, and FIG. 2 shows an embodiment of the present invention. In the figure, 1 is a switch, 2 is an AC power supply, 3 is a rectifier circuit, 4
is fuse, 5 protective resistor, 6 is capacitor, 7 is detection circuit, 8 is switch, 9 is load, 10-1 is panel, 1
1 is a connector, 11-1 is a connector, 11-2 is a connector on the insertion side, 12-1 to 12-n, 13-1
, 13-3 to 13-11 are connection bin terminals, 13-2 is a connection bin terminal whose pin is shorter than other pin terminals, and 14 is a shorting piece for a protective resistor.

Claims (1)

[Claims] When inserting a panel into an electronic device, the inrush current at the time of inserting the panel is suppressed by connecting a protective resistor in series with the capacitor of the power supply rectifier circuit. The short-circuit connecting pin of the side connector is set so that the short-circuit connecting pin is shorter than the other connecting pins, and the short-circuit connecting pin is connected after the circuit of the panel is connected to the electronic device through the connector. When the panel is inserted, the protective resistor and the capacitor form a series connection, and then the protective resistor is short-circuited with the short-circuit connection bin, and the charging voltage of the capacitor is supplied to the panel. Features an inrush current suppression circuit.