JP3145307B2 - Multi-output type power supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a fail-safe technique of a multi-output type power supply.

[0002]

2. Description of the Related Art In general, when a multi-output type power supply is operated, a fail-safe technique is used so that a stable power can be supplied to a load even when a failure (failure) such as an abnormal decrease in output and an output cutoff occurs. A redundant parallel operation in which a plurality of the same power supply devices are connected in parallel and operated is performed, thereby ensuring high reliability as the power supply device.

As a general multi-output type power supply device operated in parallel in a redundant manner, there is a power supply device as shown in a circuit diagram of FIG. 5, and this power supply device includes a power supply circuit 10 and a And an output circuit group 20 to which power is supplied. The circuit group 20 includes, for example, three output circuits 21 to 23 having substantially the same configuration.
Outputs different output voltages V1 to V3 from the respective main body channels Ch1 to Ch3 based on the power supplied from the power supply circuit 10. The number of output circuits of the output circuit group 20 is not limited to the above example, and may be 2 or 4 or more depending on the application.

The power supply circuit 10 removes noise of an AC voltage AC supplied from a commercial power supply by a noise filter NF, and then sets a thyristor TH and a resistor R for preventing an inrush current.
The rectification is performed by the rectification bridge circuit DB via the reference numeral 10. The obtained rectified voltage is smoothed by the smoothing capacitors C10 and C11, passed through a PFC circuit (Power Factor Corrector) for power factor improvement, and supplied to the output circuit group 20 as electric power via the noise removing capacitor C12.

Each output circuit 21 constituting the output circuit group 20
Reference numerals 23 to 23 denote well-known DC-CD converters.
1 to V3 are monitored, and the pulse width modulation circuits PWM1 to PWM3 control the driving pulse outputs of the switching transistors Q1 to Q3 to control the current flowing to the primary sides of the main transformers T1 to T3. Then, a voltage is excited from the secondary sides of the main transformers T1 to T3, and this is applied to each diode D21.
a to D23a, D21b to D23b, reactance RE
Output voltages V1 to V3 maintained at desired constant values can be obtained by passing through rectifying and smoothing circuits including capacitors 1 to 3 and capacitors C21 to C23, respectively.

A plurality of multi-output type power supply devices 1 having the above-described configuration, usually one more, are prepared, and the channels having the same output voltage V1 to V3 are connected in parallel between these two devices to perform the redundant operation. It does. Then, even if one of the devices fails and causes a failure such as an output drop, the output voltage is supplied from the other device.

[0007]

However, in the above-described multi-output type power supply device, the configuration in which two devices having the same configuration are prepared is literally to ensure high reliability. In spite of being redundant and originally designed not to cause a failure, double the configuration required for power supply design as a countermeasure against the failure, for example, occupying twice the volume, weight and cost. This is wasteful and departs from the technical requirements of small size, light weight and low cost.

The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a high reliability such that the power supply to the load can be maintained even if the output fails in the power supply body. Another object of the present invention is to provide a multi-output type power supply device that can be reduced in size, weight, and cost while securing the power.

[0009]

To achieve the above object, according to the present invention, there is provided a multi-output type power supply device comprising a power supply body for outputting a plurality of output voltages through a plurality of body channels. common to only set the auxiliary power supply circuit having one auxiliary channel which is connected in parallel with each body channel, by detecting the output voltage the each body channel, of any of the output voltage of the power supply body Upon detecting a drop, the auxiliary power supply circuit, a of outputting a setting voltage of the output voltage via the auxiliary channel
Between the main body channel and the auxiliary channel.
Has a set of relays for each of the main channels.
And one of the relays in each set is
The output voltage of the body channel connected between terminals
The other of the relays is turned on
The set voltage of the lowered output voltage is
Output through a channel and after said one of said relays
The step side and the high pressure side of each main body channel
The output is connected via a diode
The high side of the voltage is connected to the high side of the auxiliary channel.
It becomes.

[0010]

Further, the output voltage of the one auxiliary channel is equal to or higher than the maximum set voltage of the output voltage of the main body channel, and the set voltage is output from the auxiliary channel via a step-down circuit. Preferably.

Further, it is preferable that a reference voltage variable circuit is provided in the auxiliary power supply circuit, and the reference voltage for determining the output voltage of the auxiliary power supply circuit is made variable by the reference voltage variable circuit. Furthermore, the auxiliary channel
When the set voltage is not output to the main channel
Means that the auxiliary channel is a relay
It is preferable to be insulated through the.

In the present invention having the above-described configuration, when the output voltage of any one of the power supply main bodies decreases, the set voltage of the output voltage is output through the one auxiliary channel instead. Therefore, a fail-safe operation can be performed with respect to an abnormal voltage drop of the power supply main body, and the voltage supply to the load can be highly reliable.

Further, since the auxiliary power supply has one auxiliary channel, the configuration of the auxiliary power supply can be much smaller than that of the power supply main body having a plurality of channels. Therefore, it is not necessary to perform a plurality of identical power supply units in parallel in a redundant manner, which has been conventionally performed for fail-safe operation of the power supply unit, and the operation can be performed by itself. For this reason,
The number of parts, occupied volume, weight, and cost can be significantly reduced.

Further, when the voltage output from the one auxiliary channel is equal to or higher than the maximum set voltage of the output voltage of the main body channel and the voltage is output from the auxiliary channel via a step-down circuit, With this step-down circuit, the voltage output from the auxiliary channel can be adjusted appropriately to the reduced set value of the output voltage of the main channel. Accordingly, a single reference voltage and a feedback circuit using an error amplifier and the like connected to the reference voltage alone adjust the above-mentioned voltage of the auxiliary channel by one. Outputs can be covered by channels.

Further, when a reference voltage variable circuit is provided in the auxiliary power supply circuit and the reference voltage for determining the output voltage of the auxiliary power supply circuit is made variable by the reference voltage variable circuit, the voltage output from the auxiliary channel Can be appropriately adjusted to the set value of the output voltage of the main body channel, which is reduced. Accordingly, a single reference voltage and a feedback circuit using an error amplifier and the like connected to the reference voltage alone adjust the above-mentioned voltage of the auxiliary channel by one. Outputs can be covered by channels.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The first embodiment of the present invention will be described with reference to FIG. 1. The multi-output type power supply of the present embodiment is the same as the multi-output type power supply 1 of FIG. ) Is connected to an auxiliary power supply circuit 30 having one auxiliary channel Ch4.

The power supply main body 1 has a main body channel of, for example, 3
A channel is used, and its configuration and operation have been described in the section of the prior art, and thus are omitted to avoid duplication.
The configuration of the auxiliary power supply circuit 30 will be described. This circuit 30 is a well-known DC-D having a function of rectifying and smoothing alternating current.
It is a C converter. A rectifier bridge circuit DB is connected between the terminals of the noise filter NF connected to the commercial power supply AC via an inrush current preventing thyristor TH and a resistor R30, and a smoothing capacitor C is connected to a subsequent stage. Further, between the terminals of the smoothing capacitor C, the primary side of the main transformer T4 and the switching transistor Q
4 is connected in series.

The secondary side of the main transformer T4 is connected to each of the main transformers T1 to T1 in the output circuits 21 to 23 of the power supply body 1.
It has the same configuration as the secondary side of T3. A pair of rectifier diodes D30a and D30b are connected between the secondary side terminals, and a reactor RE4 as a choke coil and a smoother are provided between the terminals of the rectifier diode D30b. A series circuit with the capacitor C30 is connected. The voltage between the terminals of the capacitor C30 becomes the output voltage V4 of the auxiliary channel Ch4.

A pulse output terminal of a pulse width modulation circuit PWM4 is connected to the base of the switching transistor Q4. Each output terminal of the comparator COMP and the reference oscillator OSC is connected to this pulse width modulation circuit. The comparator COMP includes a reference oscillator OSC and an error amplifier AM.
P is connected to each output terminal, and the error amplifier AM
The high voltage side of the reference voltage Vref is connected to the positive terminal of P, and the high voltage side of each of the main body channels Ch1 to Ch3 of the power supply main body 1 is connected to the negative side of the relay RL1b to RL3b.
And so on. Further, resistors R and R 'connected in series are connected between the minus terminal of the error amplifier AMP and the low voltage side of the reference voltage Vref.

Each of the main body channels Ch1 to C of the power supply main body 1
The connection structure between h3 and the auxiliary channel Ch4 of the auxiliary power supply circuit 30 will be described.
3, the auxiliary channel Ch4 of the auxiliary power supply circuit 30 is commonly connected in parallel via a set of relays for each of the main body channels Ch1 to Ch3. These three sets of relays RL1, RL1a and RL1b, and RL
2, RL2a and RL2b, and RL3, RL3a and R
L3b is configured to open and close in conjunction with each set, and the corresponding relays RL1, RL2, RL3 are connected between the terminals of the main body channels Ch1 to Ch3. Then, corresponding diodes D1 ', D2', D3 'are connected to the high voltage sides of the main body channels Ch1 to Ch3 at the subsequent stage of each of the relays RL1, RL2, RL3. A series circuit of the corresponding relays RL1a to RL3a and diodes D1 to D3 is connected between the high voltage side of the auxiliary channel Ch4 of the auxiliary power supply circuit 30 and between the cathodes of the diodes D1 'to D3'.

The corresponding relays RL1b to RL1b are connected between the cathodes of the diodes D1 'to D3' connected to the high voltage sides of the main body channels Ch1 to Ch3 and the minus terminal of the error amplifier AMP of the auxiliary power supply circuit 30, respectively. A series circuit of RL3b and resistors R1 to R3 is connected, and the minus terminal is connected to a power supply V for driving the error amplifier AMP.
cc is connected via a resistor R4.

Next, the operation of the apparatus of this embodiment will be described. When the power supply main body 1 is operating normally, the relay R
L1 to RL3 maintain an ON state, and relays RL1a to RL3a, RL1b to RL3 linked to these relays
b maintains the off state as shown. Therefore, both the high voltage side of the auxiliary channel Ch4 of the auxiliary power supply circuit 30 and the minus terminal of the error amplifier AMP are opened,
The auxiliary power supply circuit 30 does not operate.

However, in the case where the output of the power supply main body 1 fails, for example, a case where the output voltage V1 has a dropping fault will be described as an example, the relay RL1 detects the drop of the output voltage V1 and turns off. In conjunction with relay RL1
Both a and RL1b are turned on. Then, the normal output voltage (set voltage) V1 from the auxiliary channel Ch4 of the auxiliary power supply circuit 30 via the relay RL1a and the diode D1.
Is output instead of the main body channel Ch1.

The output voltage V4 of the auxiliary power supply circuit 30
When the relays RL1a and RL1b are both turned on, an AC AC from a commercial power supply flows into the auxiliary power supply circuit 30, and after removing noise of the AC AC by the noise filter NF, a rush current preventing operation is performed. Thyristor T
The current is rectified by the rectifier bridge circuit DB via H and the resistor R30. The obtained rectified voltage is smoothed by the smoothing capacitor C and applied to a series circuit of the primary side of the main transformer T4 and the switching transistor Q4. The switching transistor Q4 performs a switching operation by the pulse output of the pulse width modulation circuit PWM4, and controls the current flowing to the primary side of the main transformer T4. Then, a voltage is excited from the secondary side of the main transformer T4, and this voltage is applied to each of the diodes D30a and D30b, the reactance RE4,
Through the rectifying / smoothing circuit including the capacitor C30 and the capacitor C30, a normal voltage (set voltage) corresponding to the failed output voltage V1 is output.

The operation of stably outputting this voltage will be described. The output voltage V4 from the auxiliary channel Ch4 output via the relay RL1a and the diode D1 will be described.
Is applied to the minus terminal of the error amplifier AMP via the on-state relay RL1b and the resistor R1. The applied output voltage V4 is compared with the reference voltage Vref by the error amplifier AMP, and the error output is amplified and input to one input terminal of the comparator COMP. The comparator COMP compares the input error output with the reference triangular wave from the reference oscillator OSC and outputs a pulse signal. Based on the pulse signal, the pulse width modulation circuit PWM4 drives the switching transistor Q4 on and off. As a result, the output of the auxiliary channel Ch4 maintains the set voltage corresponding to the output voltage V1 of the power supply body 1.

The operation described above is the same as that of the other main body channel C.
The same applies even if the output voltages V2 and V3 from h2 and Ch3 fail. The auxiliary power supply circuit 30 outputs each set voltage corresponding to each of the output voltages V1 to V3 by appropriately setting the voltage division ratio of the resistors R1 to R3 connected to the minus terminal of the error amplifier AMP.

The resistor R4 is connected to the relays RL1b to RL
When the power supply 3b is off, that is, when the normal power supply body 1 is operating normally, the output voltage V4 of the auxiliary channel Ch4 is set to a standby state at an arbitrary voltage. At this time, if the output voltage is set to the minimum value among the output voltages V1 to V3, the stress of the circuit element can be reduced when the connected load is switched.

In the above, the case where the number of the main body channels is three has been described as an example. However, when the number of the main body channels is two, any of the main body channels Ch1 to Ch3 may be omitted. For example, when eliminating the main body channel Ch2, the output circuit 22 of the power supply main body 1 is eliminated, and a set of relays RL2, RL2a, RL2b,
The diodes D2 'and D2 and the resistor R2 may be eliminated. The same applies when the main body channel Ch1 or Ch3 is eliminated.

When the number of channels is four or more, each output circuit 2 in the case of three channels described above is used.
Just like the connection structure between 1 to 23, an output circuit, a set of relays opened and closed in conjunction with each other, a resistor and a diode may be added. For example, increase 1 channel and 4
Assuming that the channel is a channel, the output circuit having the same configuration as the output circuit 22 of the power supply main body 1 and having the circuit constants changed so that the output voltage is different from the other output circuits is replaced with the output circuits 21 to 2 described above.
In the same manner as in the case 3, the capacitor C12 is connected. For the body channel by the added output circuit,
As in the case of the output circuits 21 to 23 described above, a relay and a diode are connected, and a series circuit of the relay and the diode is interposed between the cathode side of the diode and the high voltage side of the auxiliary channel. A series circuit of a relay and a resistor may be interposed between the negative terminal of the error amplifier AMP. In the case where the number of channels is five or more, similarly, an output circuit and a relay attached thereto may be sequentially added.

Next, a modification of the first embodiment of FIG. 1 will be described with reference to FIG. 2. This modification is based on a configuration example in which the main body channels Ch1 and Ch2 of the power supply main body 1 are insulated from each other. The present invention is applied to the case where the number of main body channels is two.

The configuration of the power supply body 1 is merely a two-output type configuration without the output circuit 23 of the first embodiment shown in FIG. 1, and the configuration and operation are omitted because they are the same as those described above. The configuration of the auxiliary power supply circuit 30 is also the same as that of FIG. 1, and the details of the configuration and operation are omitted because they are the same as those described above.

The difference between this modification and the first embodiment is that the main channels Ch1 and Ch2 and the auxiliary channels C
h4 is a connection structure. That is, the auxiliary channel Ch4
Is a set of relays RL1, RL that open and close in conjunction with each other
1a and a diode D1 connected to the main body channel Ch1 of the power supply main body 1, and a pair of relays RL2, RL2a and a diode D that open and close in conjunction with each other.
2 and is connected to the main body channel Ch2. Each of the relays RL1a and RL2a, which is one of the relays of each set, includes two relay contacts, and these two relay contacts are both opened and closed to perform the same opening and closing operation.

More specifically, the high voltage side of the output voltage V1 from the main body channel Ch1 via the diode D1 'is connected to the high voltage side of the auxiliary channel Ch4 via the diode D1 via one relay contact of the relay RL1a.
The low voltage side of the output voltage V1 from the main body channel Ch1 is
The low voltage side of the capacitor C4 connected to the primary side of the main transformer T4 of the auxiliary power supply circuit 30 is connected via the other relay contact of the relay RL1a. Also, the output voltage V through the diode D2 'from the main body channel Ch2.
2 is connected to the diode D2 of the auxiliary channel Ch4.
Is connected to the high voltage side via one relay contact of the relay RL2a, and the low voltage side of the output voltage V2 from the main body channel Ch2 is connected to the low voltage side of the auxiliary channel Ch4 via the other relay contact of the relay RL2a. It is connected. Also, the diode D from the main body channel Ch1
The high voltage side of the output voltage V1 that has passed through the auxiliary power supply circuit 3 via one of the relay contacts of the relay RL1a and the resistor R1.
0 is connected to the minus terminal of the amplifier AMP, and the high voltage side of the output voltage V2 from the main body channel Ch2 via the diode D2 'is connected to one of the relay contact of the relay RL2a and the resistor R2. Connected to the negative terminal of AMP.

In the configuration described above, the low voltage side of the main body channel Ch1 and the low voltage side of the main body channel Ch2 are not electrically connected, and are insulated by the main transformer T4 of the auxiliary power supply circuit 30. I have. Therefore, the main body channels Ch1 and Ch2 are insulated from each other.

Next, the operation of the device of this modification will be described. For example, when the output voltage V1 of the power supply main body 1 fails, the relay RL1 is turned off and the corresponding relay RL1a
Turns on. As a result, a normal output voltage (set voltage) V1 is output from the auxiliary channel Ch4 of the auxiliary power supply circuit 30 via one contact of the relay RL1 instead of the main body channel Ch1.

The operation described above is the same as that of the other main body channel C.
The same is true even if the output voltage V2 from h2 fails.
When the number of main body channels is three or more, each output circuit 21 in the case of two channels is used.
Just like the connection structure between 22, an output circuit, a set of relays that open and close in conjunction with each other, a resistor and a diode may be added.

In the above-described modified example, since the main body channels Ch1 and Ch2 are insulated from each other, insulation between the main body channels is ensured when a large current is output from the output circuit group 20 or the like. Suitable for required applications.

Next, a second embodiment of the present invention will be described with reference to FIG. 3. In the second embodiment, the first embodiment
One auxiliary channel Ch4 for the power supply body 1 in the form
However, in this example, unlike the above-described embodiment, the main body channel is set to three channels, and C of the three channels is connected.
h1 and Ch2 and the auxiliary channel Ch of the auxiliary power circuit 30
4, a known series regulator, that is, a step-down circuit 40 is interposed. Then, for the remaining main body channel Ch3, the auxiliary channel Ch4
Are connected via a relay RL and a relay RLa. Further, the output voltage V4 of the auxiliary channel Ch4 is the maximum set voltage among the main body channels Ch1 to Ch3. For example, in this embodiment, the output voltage V3 of the main body channel Ch3 is the maximum set voltage.

The configuration of the power supply body 1 of this embodiment is the same as that of the first power supply described above.
The configuration is the same as that of the first embodiment, and the configuration of the auxiliary power supply circuit 30 is different from that of the first embodiment only in the input side of the amplifier AMP. That is, the amplifier A
The negative terminal of MP is connected to the high voltage side of the auxiliary channel Ch3, and its positive terminal is connected to the high voltage side of the reference voltage Vref. Therefore, the configuration of the power supply body 1 and the auxiliary power supply circuit 30 is the same as that of the first embodiment except for the points described above, and the description is omitted to avoid duplication.

The configuration of the step-down circuit 40 will be described.
The capacitor C1 is connected between the terminals of the capacitor C1, and a series circuit of voltage dividing resistors R1 and R1 'is connected between the terminals of the capacitor C1. The connection point between the voltage dividing resistors R1 and R1 'is connected to the minus terminal of the first comparator COMP1, and the plus terminal of the first comparator COMP1 is connected to the high voltage side of the first reference voltage Vref1. ing. The low voltage side of the first reference voltage Vref1 is connected to the low voltage side of the auxiliary channel Ch4. The output terminal of the first comparator COMP1 is connected to the switching transistor Q1 via the resistor R1b.
Of the switching transistor Q
The base 1 and the collector 1 are connected via a resistor R1a. This collector is connected to the high voltage side of the auxiliary channel Ch4.

A capacitor C2 is connected between the terminals of the channel Ch2 of the power supply body 1, and a series circuit of the voltage dividing resistors R2 and R2 'is connected between the terminals of the capacitor C2. The connection point between the voltage dividing resistors R2 and R2 'is connected to the minus terminal of the second comparator COMP2, and the plus terminal of the second comparator COMP2 is connected to the high voltage side of the second reference voltage Vref2. ing. The low voltage side of the second reference voltage Vref2 is the auxiliary channel Ch.
4 is connected to the low pressure side. Second comparator COMP2
Is connected to the base of a switching transistor Q2 via a resistor R2b, and the base and collector of the switching transistor Q2 are connected via a resistor R2a. This collector is the auxiliary channel Ch4
Is connected to the high-pressure side.

Further, a relay RL is connected between the terminals of the channel Ch3 of the power supply body 1, and a diode D 'is connected to the high voltage side on the subsequent stage. A relay RLa and a diode D
Is connected to the relay RLa, and the high voltage side of the auxiliary channel Ch4 is connected to the relay RLa. The relay RLa opens and closes in conjunction with the relay RL.

The operation of the apparatus according to the second embodiment described above will be described. Should the output voltage V3 of the main body channel Ch3 fail, the relay RL is turned off and the relay RL is turned on, and the voltage of the auxiliary channel Ch4 is turned on. Is output as it is via the diode D as the output voltage V3.

Output voltage V1 from main body channel Ch1
Is constantly detected by the capacitor C1 and the resistances R1 and R1 ', and is detected by the comparator COMP1 and compared with the reference voltage Vref1. By this,
When the output voltage V1 output from the power supply main body 1 fails, the output of the comparator COMP1 is inverted to turn on the switching transistor Q1, and the output voltage from the auxiliary channel Ch4 is stepped down to the preset output voltage V1. Output. When the output voltage V2 output from the power supply main unit 1 fails, the same operation is performed for backup.

At this time, each switching transistor Q
1, the on level of Q2 is the main channel Ch1, Ch2
Are set slightly lower than the respective set voltages, and are normally turned off. That is, the tracking method is used according to the fluctuations of the output voltages V1 and V2.

The level at which the output voltage V4 from the auxiliary channel Ch4 drops to the output voltages V1 and V2 depends on the level of the capacitors C1 and C1 connected to the input sides of the first and second comparators.
C2, resistors R1, R1 ', R2, R2', and
It is determined by setting the circuit constant of the reference voltage of 2.

Although the channel outputting the maximum set voltage among the main channels is described as Ch3, it may be any one of the main channels Ch1 and Ch2.
In this case, the relays RL and RLa and the diodes D and D 'are connected to the channel outputting the maximum set voltage in the same manner as described above, and the step-down circuit 40 is described above for the remaining channels Ch1 and Ch2. Connect as before.

In the above, the case where the number of the main channels is three has been described as an example. However, when the number of the main channels is two, any of the main channels Ch1 and Ch2 may be omitted. For example, when eliminating the main body channel Ch2, the output circuit 22 of the power supply main body 1 may be eliminated, and a circuit portion of the step-down circuit 40 connected thereto for backing up the output voltage V2 from the main body channel Ch2 may be eliminated. That is, the transistor Q2, the second comparator COMP2, the capacitor C2, the second reference voltage Vre
f2 and resistors R2, R2 ', R2a,
What is necessary is just to make it the structure which eliminated R2b.

When the number of channels is four or more, each output circuit 2 in the case of three channels described above is used.
While adding an output circuit of the same configuration as between 1 and 23,
A transistor, a comparator, a capacitor, a reference voltage, and a resistor to be connected to the added output circuit may be added and connected in the same manner as in the case of FIG.

In the second embodiment described above, the voltage V4 output from the auxiliary channel Ch4 is applied to the main channel C4.
Since the output voltage is higher than the maximum set voltage of the output voltages V1 to V3 of h1 to h3 and is output from the auxiliary channel Ch4 via the step-down circuit 40, the voltage output from the auxiliary channel Ch4 is reduced by the step-down circuit 40. The set value of the output voltage of the main body channel can be appropriately adjusted. Therefore, a wide range of output voltages of the main body channels Ch1 to Ch3 cannot be covered only by adjusting the output voltage V4 of the auxiliary channel Ch4 only by a single reference voltage and a feedback circuit using an error amplifier or the like connected thereto. The range can be output by covering one auxiliary channel Ch4.

Next, a third embodiment of the present invention will be described with reference to FIG. 4. In this example, unlike the above-described embodiment, an auxiliary power supply circuit 30A having one auxiliary channel Ch4 is connected to the power supply main body 1. , The auxiliary power supply circuit 30
A is provided with a reference voltage variable circuit 50.

Between the terminals of each main body channel (three channels in this example) Ch1 to Ch3 of the power supply main body 1, the resistors R1 to R1 are connected.
R3 is connected. This power supply body 1 is the first power supply
The configuration is exactly the same as that of the embodiment, and its configuration and operation are omitted because they are the same as those described above. The auxiliary power supply circuit 30A will be described. A rectifier bridge circuit DB is connected between the terminals of a noise filter NF connected to the commercial power supply AC via a thyristor TH for preventing inrush current and a resistor R4a, and is smoothed in the subsequent stage. The capacitor C4a is connected. Also, the smoothing capacitor C
4a between the primary windings P and F of the main transformer T4.
A series circuit with a switching transistor Q4 made of ET is connected. A primary circuit of the main transformer T4 is connected to a parallel circuit of a resistor R4b and a capacitor C4b and a series circuit of a diode D4a. An auxiliary winding P 'is provided on the primary side of the main transformer T4. A diode D4a is connected to one terminal of the auxiliary winding P'. The cathode of the diode D4a and the other of the auxiliary winding P ' And a capacitor C4c is connected between the terminals. These diode D4a and capacitor C4c
Is connected to a power input terminal of the pulse width modulation circuit PWM4. A resistor R4 is connected between the power input terminal and the high voltage side of the capacitor C4a.
e is connected. The source and drain of the switching transistor Q4 are connected between the other terminal of the auxiliary winding P 'and one terminal of the primary winding of the main transformer T4. The gate of the switching transistor Q4 is connected to a pulse output terminal of the pulse width modulation circuit PWM4 via a resistor R4c, and a resistor R is connected between the gate and the source.
4d. The collector of a phototransistor PT forming a photocoupler together with a light emitting diode LED described later is connected to a voltage detection terminal of the pulse width modulation circuit PWM4.

A diode D4 for rectifying and smoothing and a capacitor C4 are connected between the secondary terminals of the main transformer T4, a resistor R4f is connected between the terminals of the capacitor C4, and an auxiliary channel is connected between the terminals of the resistor R4f. Ch
4 is output. This auxiliary channel Ch
4 are provided with switches SW1 to 3 and diodes D1 to
It is connected to the high pressure side of the main body channels Ch1 to Ch3 via D3. These switches SW1 to SW3 have, for example, the same configuration as the relays RL and RLa of the second embodiment shown in FIG. 3 described above. When each output voltage V1 to V3 fails and drops, the corresponding switches SW1 to 3 are turned on. Configuration. Between the terminals of the capacitor C4, a resistor R4g,
A series circuit of a light emitting diode LED and a shunt regulator IC that constitute a photocoupler together with the phototransistor PT described above is connected, and a resistor R4
h, R4i and R4j are connected in series. The reference terminal of the shunt regulator IC is a resistor R
The resistor R4j is connected to a connection point between the resistor 4h and the resistor R4i, and the resistor R4j is connected to the reference voltage variable circuit 50.

The reference voltage variable circuit 50 includes a transistor Q
1 and a transistor Q2.
Is connected to a connection point between the switch SW1 and the diode D1 via a resistor R1a, and the base and the emitter of the transistor Q1 are connected by a resistor R1b. The collector of the transistor Q1 is connected to a connection point between the resistors R4i and R4j of the auxiliary power supply circuit 30A. The base of the transistor Q2 is connected to a switch S via a resistor R2a.
The transistor Q2 is connected to a connection point of W2 and the diode D2, and the base and the emitter of the transistor Q2 are connected by a resistor R2b. The collector of the transistor Q2 is connected to a connection point between the resistors R4i and R4j of the auxiliary power supply circuit 30A via a resistor R2c.

Next, the operation of the device according to the third embodiment will be described. When the power supply main body 1 is operating normally,
The switches SW1 to SW3 are kept off. Therefore, the auxiliary channel Ch4 high voltage side of the auxiliary power supply circuit 30A is opened, and the auxiliary power supply circuit 30A does not operate. Also, since no voltage is applied to the bases of the transistors Q1 and Q2, the reference voltage variable circuit 50 does not operate while maintaining the off state.

However, in the case where a certain output of the power supply main body 1 fails, for example, a case where the output voltage V1 drops and a fault occurs, the switch SW1 is turned on. Then, the auxiliary channel Ch of the auxiliary power supply circuit 30A
4 outputs a normal output voltage V1 via the switch SW1 and the diode D1.

The output voltage V of the auxiliary power supply circuit 30A
Regarding the supply operation of No. 4, when the switch SW1 is turned on, AC AC from a commercial power supply flows into the auxiliary power supply circuit 30A, and after the noise of this AC AC is removed by the noise filter NF, the thyristor TH for preventing inrush current is supplied. And rectified by the rectifier bridge circuit DB via the resistor R4a. The obtained rectified voltage is smoothed by the smoothing capacitor C4a and applied to a series circuit of the primary winding of the main transformer T4 and the switching transistor Q4. This switching transistor Q4 performs a switching operation by the pulse output of the pulse width modulation circuit PWM4, and the main transformer T4
To control the current flowing to the primary side. Then, a voltage is excited from the secondary side of the main transformer T4, and this voltage is applied to each diode D4, capacitor C4, and resistors R4f to R4h.
, A normal voltage corresponding to the failed output voltage V1 is output.

The operation of stably outputting this voltage will be described. The voltage V4 output via the auxiliary channel Ch4 is applied between the cathode and the anode of the shunt regulator IC via the resistor R4g and the light emitting diode LED. The light emitting diode LED blinks based on the output voltage V4 and the reference voltage determined by the shunt regulator IC, the voltage dividing resistors R4i and R4j, and the reference voltage variable circuit 50, and the excitation voltage of the phototransistor PT corresponding to the blinking. Determines the pulse output of the pulse width modulation circuit PWM, so that the output voltage V4 becomes the normal output voltage V1.

Output voltage V4 from reference voltage variable circuit 50
When the operation of changing the reference voltage for determining the threshold voltage is described, the switch SW1 is turned on and the transistor Q1 is turned on. As a result, the voltage dividing resistor R4i and the transistor Q
The reference voltage for the normal output voltage V1 is determined by the threshold voltage of the shunt regulator IC according to the combined resistance of the series circuit with the ON resistance of No. 1, and the output voltage V4 of the auxiliary channel Ch4 is changed to the normal output voltage V1.
Becomes The same applies to a case where the output voltage V2 of the main body channel Ch2 fails, in which the switch SW2 is turned on and the transistor Q2 is turned on. Thus, the reference voltage for the normal output voltage V2 is determined by the threshold voltage of the shunt regulator IC in accordance with the combined resistance of the voltage dividing resistor R4i, the resistor R2c, the resistor R4j, and the on-resistance of the transistor Q1. The output voltage V4 of the channel Ch4 becomes the normal output voltage V2. This normal output voltage V2 is output via the switch SW2 and the diode D2.

In the above, the case where the number of the main channels is three has been described as an example. However, when the number of the main channels is two, any of the main channels Ch1 and Ch2 may be omitted. For example, when eliminating the main body channel Ch2, the output circuit 22 of the power supply main body 1 may be eliminated, and the switch SW2, the diode D2, and the resistor R2 attached thereto may be eliminated. The same applies when the body channel Ch1 is eliminated.

When the number of channels is four or more, each output circuit 2 in the case of three channels described above is used.
In exactly the same manner as the connection structure between 1 and 23, an output circuit, a resistor, a diode, and a switch connecting the increased number of body channels are added, and a transistor of the reference voltage variable circuit 50 and its peripheral resistance are added accordingly. I just need. For example, 1
If the number of channels is increased to 4 channels,
The output circuit 22 having the same configuration as that of the output circuit 22 and having the circuit constants changed so that the output voltage is different from that of the other output circuit 22 is replaced with the capacitor C12 of the power supply circuit 10 in the same manner as the output circuits 21 to 23 described above. Connect to A resistor, a diode, and a switch are connected to the body channel of the added output circuit in the same manner as in the case of the output circuits 21 to 23, and a reference voltage variable circuit is provided between the anode of the diode and the switch. The base of the transistor added to 50 is connected via a resistor. The base and the emitter of this transistor may be connected via a resistor, and the collector may be connected between the resistors R4i and R4j of the auxiliary power supply circuit 30A via the resistor.

Further, the above-described auxiliary power supply circuit 30A
Although the primary-side control method is such that the power supply of the pulse width modulation circuit PWM4 is obtained from the primary-side auxiliary winding P 'of the main transformer, the present invention is not limited to this, and the auxiliary power supply circuit 30 in FIGS. . Further, a circuit using a shunt regulator IC, a photocoupler, or the like, such as the auxiliary power supply circuit 30A of the third embodiment, can be applied to the first and second embodiments and the modifications of FIGS.

In the third embodiment described above, the auxiliary power supply circuit 30A is provided with a reference voltage variable circuit 50, and the reference voltage for determining the output voltage V4 of the auxiliary power supply circuit 30A is provided by the reference voltage variable circuit 50. Since the voltage is variable, the voltage V4 output from the auxiliary channel Ch4 can be appropriately adjusted to the set value of the output voltage of the reduced main body channel. Therefore, a single reference voltage and a feedback circuit using an error amplifier and the like connected to the reference voltage alone can adjust the output voltage of the auxiliary channel to a single auxiliary voltage. The output can be covered by the channel Ch4.

In the above-described first to third embodiments of the auxiliary power supply circuits 30, 30A, standard commercial products can be used, and there is no need to newly develop them.

Further, in the first to third embodiments, instead of using a mechanical relay to back up from the auxiliary channel Ch4 performed by each relay, a switching transistor is provided in the same manner as in the case of the step-down circuit 40 in FIG. It may be used. More specifically, the comparator compares the reference voltage with the output voltages V1 to V3, and drives the switching transistor on and off with the output to perform backup from the auxiliary channel Ch4. A faster response can be secured.

For each of the output voltages V1 to V3,
Not only voltages different from each other but also the same voltage can be backed up by the auxiliary power supply circuit 30 of the present invention.

[0068]

As described above, in the present invention,
The power supply to the load can be maintained without interruption when the output of the power supply unit fails, and high reliability of the power supply can be secured. Therefore, the power supply device of the present invention can be operated alone by eliminating the conventional parallel operation of the redundant system. For this reason, the fail-safe of the power supply main body can be secured, and the size, weight, and cost can be extremely reduced.

When the output voltage of the one auxiliary channel is equal to or higher than the maximum set voltage of the output voltage of the main body channel, and the output voltage is output from the auxiliary channel via a step-down circuit, The output voltage range of the main unit channel can be widened by one auxiliary channel, which cannot be covered only by adjusting the voltage of the auxiliary channel by only a feedback circuit using a single reference voltage and an error amplifier connected thereto. To cover and output.

Further, when the reference voltage variable circuit is provided to the auxiliary power supply circuit and the reference voltage for determining the output voltage of the auxiliary power supply circuit is made variable by the reference voltage variable circuit, a single reference voltage And a single auxiliary channel to cover a wide range of output voltage range of the main body channel which cannot be covered only by adjusting the output voltage of the auxiliary channel only by a feedback circuit using an error amplifier or the like connected thereto. it can.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a multi-output power supply device according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram of a multi-output type power supply device according to a modification of the device of FIG.

FIG. 3 is a circuit diagram of a multi-output power supply device according to a second embodiment of the present invention.

FIG. 4 is a circuit diagram of a multi-output power supply device according to a third embodiment of the present invention.

FIG. 5 is a circuit diagram in which conventional multi-output power supplies are connected in parallel.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Power supply body 10 Power supply circuit 20 Output circuit group 21-23 Output circuit 30 Auxiliary power supply circuit 40 Step-down circuit 50 Reference voltage variable circuit COMP1, 2 Comparator NF Noise filter T1-T3 Main transformer DB Rectifier bridge circuit PFC Power factor improvement Circuit CT Current transformer R Detection resistor AMP Error amplifier PWM1-4 Pulse width modulation circuit COMP Comparator TH Thyristor LED Light emitting diode R4d, R5d Voltage dividing resistor V1 to V3 Output voltage Ch1 to Ch3 Main channel V4 Output voltage Ch4 Auxiliary channel IC Shunt regulator Q1, Q2, Q4 Switching transistors RL1 to RL3, RL1 'to RL3', RL1 to RL3
Relays D1 to D3, D1 'to D3 Backflow prevention diodes Vref, Vref1, 2 Reference voltage

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H02J 1/00 H02J 1/10 H02M 3/28

Claims (4)

(57) [Claims] 1. A plurality of main body channels (Ch1 to Ch)
3) In a multi-output type power supply device provided with a power supply main body (1) that outputs a plurality of output voltages (V1 to V3) via the same, the respective main body channels (Ch1 to Ch3) are commonly connected in parallel. only set an auxiliary power supply circuit (30, 30A) having one auxiliary channel (Ch4), by detecting the output voltage for each respective body channel, one of the output voltage of the power supply body (1) (V1 ＶV3), the auxiliary power supply circuit (30, 30A) changes the set voltage of the output voltages (V1 to V3) to the auxiliary channel (Ch).
4) A of outputting through said between said auxiliary channel each body channel
A set of relays is provided for each of the main body channels,
One of the set of relays is connected between the terminals of each body channel.
Continue to detect a drop in the output voltage of the body channel
Then, the other of the relays is turned on and the output is lowered.
Output the set voltage of the input voltage via the auxiliary channel
And each of the relays on the rear side of the one of the relays.
A diode is connected to the high side of the body channel.
The high voltage side of the output voltage passing through this diode is
A multi-output type power supply device connected to a high voltage side of an auxiliary channel . 2. The voltage (V4) output from the one auxiliary channel (Ch4) is applied to the main body channels (Ch1 to Ch1).
Ch3) is equal to or higher than the maximum set voltage of the output voltages (V1 to V3) and outputs the set voltage from the auxiliary channel (Ch4) via a step-down circuit (40). The multi-output type power supply device according to claim 1, wherein 3. An auxiliary power supply circuit (30A) is provided with a reference voltage variable circuit (50).
The multi-output power supply device according to claim 1, wherein the reference voltage for determining the output voltage (V4) of the auxiliary power supply circuit (30A) is made variable by 0). 4. The multi-purpose device according to claim 1, wherein when the auxiliary channel does not output the set voltage to the main body channel, the auxiliary channel is insulated from the main body channel via a relay. Output type power supply.