JP2005094573A - Power supply line filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain a power loss in a main line provided to a power supply line filter on stand-by. <P>SOLUTION: The main line (1) of the power supply line filter connected between a pair of input terminals (3 and 4) connected to an AC power supply and a main load (8) is equipped with a switch (9) which controls an electric power supplied to the main load (8), a first filter circuit (6) connected between the input terminals (3 and 4) and the input of the switch (9), and a second filter circuit (7) connected between the output of the switch (9) and the main load (8). A first discharge circuit (5a) and a second discharge circuit (5b) are connected to the first filter circuit (6) and the second filter circuit (7) respectively, and an auxiliary line (2) connected to an auxiliary load (20) is connected between the first filter circuit (6) and the input of the switch (9) of the main line (1). When the input terminals (3 and 4) are disconnected from a commercial power supply, electrical charge accumulated in capacitors (13, 15, 17. and 31) is discharged through the first and second discharge circuit (5a and 5b), whereby an unexpected accident caused by an excessive voltage between the input terminals (3 and 4) is prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention includes a main line connected to the main load and a sub line connected between the main line and the sub load, and removes noise from the power source and consumes power during standby when the main line is shut off. It is related with the power line filter which can reduce.

  As shown in FIG. 3, the conventional power line filter includes a pair of input terminals (3,4) connected to an AC power source such as a commercial power source, an input terminal (3,4), and a main load (8). A main line (1) connected in between, and a sub line (2) connected between the main line (1) and the sub load (20) are provided. The main line (1) includes a discharge circuit (5) having discharge means such as a discharge resistor (12) or a constant current circuit connected between a pair of input terminals (3, 4), a discharge circuit (5), and a main circuit. The filter circuit (6) connected between the load (8), the input terminal (3,4) and the discharge circuit (5) and connected from the main line (1) to the main load (8). And a switch (9) for controlling the supplied power. The filter circuit (6) includes a capacitor (13) connected between a pair of main lines (1), and a reactor (14) constituting a choke coil between the pair of main lines (1) on the output side of the capacitor (13). ), A capacitor (15) connected to the output side of the reactor (14), a reactor (18) constituting the choke coil, and a capacitor (19) connected to the output side of the reactor (18). Yes. The main load (8) includes a rectifier circuit (21) connected to the filter circuit (6) and a driven circuit (10) connected to the output side of the rectifier circuit (21).

  In the example shown in FIG. 3, the sub-line (2) is connected to a discharge resistor (26) constituting a discharge circuit (23) connected between the input terminals (3, 4) and the discharge circuit (23). A filter circuit (24) and a subload (20) connected to the output side of the filter circuit (24) are provided. The filter circuit (24) includes a capacitor (27) connected between a pair of input terminals (3,4), and a reactor constituting a choke coil between a pair of sub-lines (2) on the output side of the capacitor (27). (28) and a capacitor (29) connected to the output side of the reactor (28). The subload (20) includes a rectifier circuit (22) connected to the filter circuit (24) and a driven circuit (25) connected to the output side of the rectifier circuit (22).

  Each of the rectifier circuits (21, 22) is constituted by a bridge circuit or the like having at least one rectifier that performs full-wave rectification or half-wave rectification, and driven circuits for the main load (8) and the subload (20). For (10, 25), a switching power source, a heater, a lamp, or the like or a power source or an inverter thereof is used. The switch (9) is mainly a relay, but a semiconductor switching element such as a triac, FET (field effect transistor) or transistor can also be used.

  In the power line filter shown in FIG. 3, when the switch (9) having an on / off function is turned on, power is supplied from the discharge circuit (5) and the filter circuit (6) to the main load (8), and the switch (9) Power is supplied to the sub load (20) of the sub line (2) through the discharge circuit (23) and the filter circuit (24) regardless of whether the power is on or off. A switch (9) is installed on the main line (1) on the input side of the filter circuit (6), and when the switch (9) is off, the main line (1) is separated from the input terminals (3,4) and the main load The power supply to (8) is stopped. As a result, the current flowing through the discharge circuit (5) and the filter circuit (6) can be cut off during standby of the main line (1), and power consumption during standby by the discharge circuit (5) can be reduced. Generally, a capacitor (13,15,19) in the filter circuit (6) is used because a capacitor (13,15,19) with a large capacity is used in the filter circuit (6) in the main line (1) where a large load current flows. It is necessary to pass a large amount of current through the discharge circuit (5) that discharges the electric charge. In general, the auxiliary load (20) connected to the auxiliary line (2) is often an auxiliary power source, and the filter circuit (24) through which a small load current flows may be a small capacitor (27, 29). There are many cases. Therefore, a small amount of current may be passed through the discharge circuit (20) that discharges the charges of the capacitors (27, 29) of the filter circuit (24) of the sub line (2). Discharge so that excessive voltage is not continuously output between the input terminals (3, 4) when the pair of input terminals (3, 4) connected to an AC power source such as a commercial power supply is disconnected from the AC power supply The charges accumulated in the filter circuit (6) and the filter circuit (24) are discharged through the circuit (5) and the discharge circuit (23).

  In another conventional power line filter shown in FIG. 4, a discharge circuit (5) and a filter circuit (6) are connected to a main line (1) connected to a pair of input terminals (3,4), and a filter circuit ( Connect the switch (9), rectifier circuit (21) and main load (8) to the output side of 6). Further, the sub line (2) is connected between the filter circuit (6) and the switch (9), and power is supplied to the sub load (20) through the rectifier circuit (22) of the sub line (2). In FIG. 4, the same parts as those in FIG. In the power line filter shown in FIG. 4, when the switch (9) is turned on, power is supplied to the main load (8) through the discharge circuit (5) and the filter circuit (6), and the switch (9) Regardless of the on / off operation of 9), power is supplied to the sub load (20) through the discharge circuit (5) and the first filter circuit (6).

  In the conventional power line filter shown in FIG. 3, the discharge circuit (5) capable of flowing a large discharge current during standby is disconnected by the switch (9). 23) and the filter circuit (24) need to be newly provided in the sub-line (2), so that there is a disadvantage that the circuit configuration becomes complicated.

  On the other hand, in the power supply line filter shown in FIG. 4, when the switch (9) is provided on the output side of the filter circuit (6), the switch is passed through the discharge circuit (5) and the filter circuit (6) when the main line (1) is on standby. There is a drawback that current flows and power loss increases due to the current passing through the discharge resistor (12). Since the stored energy is discharged within a certain time so that no voltage remains between the input terminals (3, 4) after the AC power applied to the pair of input terminals (3, 4) is cut off, the capacity of the discharging capacitor is large. As the discharge completion time is shortened, the resistance value of the discharge resistor (12) needs to be reduced, and the loss in the steady state increases due to the current flowing through the discharge resistor (12).

  Then, an object of this invention is to provide the power supply line filter which can suppress the power loss at the time of standby | standby which interrupts | blocks a main line. It is another object of the present invention to provide a power line filter that can reduce power loss during standby and reduce the component configuration.

  A power line filter according to the present invention includes a main line (1) connected between a pair of input terminals (3,4) connected to an AC power source and a main load (8), a main line (1), and a sub-line. And a sub line (2) connected between the load (20). The main line (1) is a switch (9) for controlling power supplied to the main load (8) through the main line (1) between the pair of input terminals (3,4) to the main load (8). And a first filter circuit (6) connected between the pair of input terminals (3, 4) and the input of the switch (9) and between the output of the switch (9) and the main load (8) And a second filter circuit (7) connected to. A first discharge circuit (5a) and a second discharge circuit (5b) are connected to the first filter circuit (6) and the second filter circuit (7), respectively, and the first filter circuit (6) and the switch are connected. Connect the sub line (2) connected to the sub load (20) until the input of (9).

  By increasing the resistance of the first filter circuit (6), particularly the first discharge circuit (5a) that discharges the energy stored in the capacitors (13, 15) with a predetermined time constant, Loss can be reduced. Further, the circuit configuration can be simplified by connecting the main line (1) to the sub-line (2) having no filter circuit between the output of the first filter circuit (6) and the switch (9). . Further, when the input terminal (3, 4) is disconnected from the commercial power source or the like, the first filter circuit (6) and the second filter circuit are passed through the first discharge circuit (5a) and the second discharge circuit (5b). Since the energy stored in (7) can be released, it is possible to prevent unexpected accidents due to the continuous output of an excessive voltage between the input terminals (3, 4).

Hereinafter, an embodiment of a power line filter according to the present invention will be described with reference to FIGS. 1 and 2, the same parts as those in FIGS. 3 and 4 are denoted by the same reference numerals, and the description thereof is omitted.
In the first embodiment according to the present invention shown in FIG. 1, a first discharge circuit (5a) having a discharge resistor (12) connected between a pair of input terminals (3,4) connected to an AC power source. A first filter circuit (6) connected to the pair of input terminals (3,4), a switch (9), a second discharge circuit (5b), and a second filter circuit (7) Are sequentially connected to the main line (1), the second filter circuit (7) is connected to the main load (8), the first filter circuit (6) of the main line (1) and the switch (9) During this period, the sub line (2) connected to the sub load (20) is connected. In the second filter circuit (7), a capacitor (17), a reactor (30) constituting a choke coil, and a capacitor (31) are sequentially connected between the switch (9) and the main load (8). The In the embodiment of the present invention, the total capacity of the capacitors (13, 15) included in the first filter circuit (6) connected between the pair of input terminals (3,4) and the switch (9) The first discharge time constant by the first discharge circuit (5a) and the capacitors (17, 17) included in the second filter circuit (7) connected between the switch (9) and the main load (8). The total capacity of 31) and the second discharge time constant by the second discharge circuit (5b) are substantially equal, and are within a predetermined discharge time constant regardless of whether the switch (9) is open or closed. Alternatively, the total capacity and the first discharge of the capacitors (13, 15) included in the first filter circuit (6) connected between the switch (9) and the pair of input terminals (3, 4). Total of the first discharge time constant by the circuit (5a) and the capacitor (17, 31) included in the second filter circuit (7) connected between the switch (9) and the main load (8) The second discharge time constant by the capacity and the second discharge circuit (5b) may be smaller than the first discharge time constant. Further, the first discharge circuit (5a) connected to the first filter circuit (6) is placed at an arbitrary position on the main line (1) between the input terminals (3, 4) and the switch (9). It has either a single discharge circuit connected or a plurality of discharge circuits connected in a distributed manner. The second discharge circuit (5b) connected to the second filter circuit (7) is connected to an arbitrary position on the main line (1) between the output of the switch (9) and the main load (8). A single discharge circuit or a plurality of discharge circuits connected in a distributed manner.

  When the switch (9) that waits for the main load (8) connected to the main line (1) is turned off, the second discharge circuit (5b) is disconnected and the second connected to the output side of the switch (9) Loss due to the discharge circuit (5b) can be eliminated. Further, there is only the first filter circuit (6) for the sub-line (2), and the first filter circuit (6), particularly the first discharge circuit for discharging the energy stored in the capacitor with a predetermined time constant ( By increasing the resistance value of the discharge resistor (12) provided in 5a), it is possible to reduce power loss during standby. Further, the sub-line (2) having no filter circuit is divided from the main line (1) on the input side of the switch (9), and the sub-line (2) is divided into the output of the first filter circuit (6) and the switch (9 ), The circuit configuration can be simplified. In addition, the second filter circuit (7) on the output side from the switch (9) through the second discharge circuit (5b) connected to the output side of the switch (9) that shuts off and waits for the main line (1), In particular, when the input terminals (3, 4) are disconnected from the commercial power supply, etc., regardless of the on / off state of the switch (9) by discharging the charge accumulated in the capacitors (17, 31) with a predetermined time constant, the input terminals Unexpected accidents due to excessive output of a continuous voltage during (3,4) can be prevented.

  FIG. 2 shows a second embodiment of the present invention in which a second filter circuit (7) having only a capacitor (17) is connected between the second discharge circuit (5b) and the main load (8). . Since the capacitor (17) can be separated by the switch (9), the first discharge circuit (5a) can use the discharge resistor (12) having a large resistance value, and energy loss can be reduced. Further, when the switch (9) is turned off, the second discharge circuit (5b) is disconnected, and the loss caused by the second discharge circuit (5b) connected to the output side of the switch (9) can be eliminated. Further, since the sub line (2) without the filter circuit can be branched from the main line (1) on the input side of the switch (9), the circuit configuration can be simplified.

  In the embodiment of the present invention, changes are possible. For example, in the embodiment shown in FIG. 1, the first filter circuit (6) has one reactor and two capacitors, but any number of filter circuits may be used. The second filter circuit (7) is configured in the same manner as the first filter circuit (6). However, in the second filter circuit (7) as shown in FIG. 2, the reactor (18) is omitted and the capacitor is omitted. (15) One or a number of stages of filters may be used. Further, the rectifier circuit (21) may be omitted depending on the load of the main circuit (1).

  The present invention is particularly effective for a power supply line filter including a filter circuit including a reactor and a capacitor.

1 is a circuit diagram of a power line filter showing a first embodiment of the present invention. Circuit diagram of a power line filter showing a second embodiment of the present invention Circuit diagram showing a conventional power line filter Circuit diagram showing another conventional power line filter

Explanation of symbols

  (1) ... Main line, (2) ... Sub line, (3,4) ... Input terminal, (5) ... Discharge circuit, (5a) ... First discharge circuit, (5b) ... Second discharge circuit, (6) ・ ・ First filter circuit, (7) ・ ・ Second filter circuit, (8) ・ ・ Main load, (9) ・ ・ Switch, (12,16) ・ ・Discharge resistor, (13,15,17,31) ・ Capacitor, (14,18) ・ Reactor, (20) ・ ・ Sub load, (21,22) ・ ・ Rectifier circuit,

Claims (6)

A main line connected between a pair of input terminals connected to an AC power source and the main load, and a sub line connected between the main line and the sub load;
The main line includes a switch that controls power supplied to the main load through the main line between the pair of input terminals and the main load, and a pair of input terminals to the input of the switch. A first filter circuit connected to the switch, and a second filter circuit connected between the output of the switch and the main load,
Connecting a first discharge circuit and a second discharge circuit to the first filter circuit and the second filter circuit, respectively;
The power line filter, wherein the sub line connected to the sub load is connected between the first filter circuit and the input of the switch.   The power line filter according to claim 1, wherein each of the first filter circuit and the second filter circuit includes a capacitor.   A total capacitance of capacitors included in the first filter circuit connected between the pair of input terminals and the switch, a first discharge time constant by the first discharge circuit, the switch and the main The total capacitance of the capacitors included in the second filter circuit connected to the load and the second discharge time constant by the second discharge circuit are substantially equal, and at a predetermined discharge time regardless of whether the switch is opened or closed. The power line filter according to claim 1 or 2, wherein the power line filter is within a constant.   A first discharge time constant by a first discharge circuit and a total capacity of capacitors included in the first filter circuit connected between the switch and the pair of input terminals; the switch and the main load; The second discharge time constant by the total capacity of the capacitors included in the second filter circuit connected between the second discharge circuit and the second discharge circuit is smaller than the first discharge time constant. The power line filter described.   The first discharge circuit connected to the first filter circuit is connected to a single discharge circuit connected at an arbitrary position on the main line between the input terminal and the switch or connected in a distributed manner. The power supply line filter according to claim 1, comprising any one of a plurality of discharge circuits.   The second discharge circuit connected to the second filter circuit is a single discharge circuit connected to any position of the main line between the output of the switch and the main load or connected in a distributed manner The power supply line filter according to claim 1, comprising any one of a plurality of discharge circuits.

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