JPH0631429Y2 - Output abnormality detection circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention detects an abnormal voltage at each output of a power supply circuit having a plurality of outputs and stops the power supply circuit by detecting the abnormal voltage. The present invention relates to a detection circuit.

[Conventional technology]

Conventionally, in a power supply circuit having a plurality of outputs such as a switching regulator, if an abnormal voltage occurs in any of the outputs due to, for example, a short circuit,
In order to detect this and stop the power supply circuit, an output abnormality detection circuit 1 as shown in FIG. 4 is provided.

That is, the output abnormality detection circuit 1 is a power supply circuit 2 having a plurality of, in the illustrated case, three outputs 2a, 2b and 2c, and an abnormal voltage detection circuit connected to each of the outputs 2a, 2b and 2c. 3, 4 and 5 and the outputs of the abnormal voltage detection circuits 3, 4 and 5 are collectively input to one common protection circuit 6 via the backflow prevention diodes, and the output of the protection circuit 6 is The voltage is supplied to a voltage control unit (not shown) of the power supply circuit 2.

According to the output abnormality detection circuit 1 configured as described above, normally, the normal voltage is output from the respective outputs 2a, 2b and 2c of the power supply circuit 2, and therefore the respective abnormal voltage detection circuits 3, 4 and 5 are provided. Does not operate, and no abnormality detection signal is output from its output, so the protection circuit 6 does not output a stop signal to the power supply circuit 2.

Here, for example, when an abnormal voltage occurs in the output 2a of the power supply circuit 2 due to a short circuit or the like, the abnormal voltage detection circuit 3 detects this abnormal voltage and outputs an abnormality detection signal, and this abnormality detection signal is transmitted via a diode. It is input to the protection circuit 6. As a result, the protection circuit 6 outputs a stop signal and the power supply circuit 2
When the stop signal is input from the protection circuit 6,
Cut off all its output.

[Problems to be solved by the invention]

However, in the output abnormality detection circuit 1 having such a configuration, an abnormal voltage is generated in any one of the outputs 2a, 2b, or 2c of the power supply circuit 2, so that the corresponding abnormal voltage detection circuit 3, 4 or 5 becomes abnormal. Since the protection circuit 6 stops the power supply circuit 2 by outputting a detection signal, when the power supply circuit 2 stops, any output 2
It is not possible to determine whether an abnormal voltage has occurred in a, 2b, 2c,
The abnormal voltage cannot be dealt with immediately, and it takes time to restart the power supply circuit 2.

Therefore, even if a display circuit including a light emitting element or the like is individually provided based on the output signals of the abnormal voltage detection circuits 3, 4, and 5, the power supply circuit 2 is activated by the operation of the protection circuit 6.
Is stopped, each abnormal voltage detection circuit 3, 4 or 5 detects an abnormal voltage at each output 2a, 2b, 2c of the power supply circuit 2, so that all display circuits perform light emission display and the like. , Any of the outputs 2a, 2b, 2
There is a problem that it cannot be determined whether an abnormal voltage has occurred in c.

In view of the above points, the present invention stops the power supply circuit and causes an abnormal voltage to occur in any of the outputs when the abnormal voltage occurs in any of the outputs of the power supply circuit having a plurality of outputs. It is an object of the present invention to provide an output abnormality detection circuit that displays whether or not.

[Means and Actions for Solving Problems]

According to the present invention, the above object is to provide a plurality of abnormal voltage detection circuits each connected to each output of a power supply circuit having a plurality of outputs, and to input an abnormal detection signal from any one of the abnormal voltage detection circuits. In the output abnormality detection circuit including a common protection circuit that outputs a stop signal to the power supply circuit, a display circuit including a light emitting element corresponding to each abnormal voltage detection circuit is provided. This is achieved by adopting a configuration in which only the output of the power supply circuit corresponding to this signal is lit and displayed based on the abnormality detection signal that is output first among the abnormality detection signals from the detection circuit. In addition, preferably, the output of each abnormal voltage detection circuit is connected to a clock input of a flip-flop, and the output of the flip-flop is provided in addition to a NAND gate provided corresponding to each output of the power supply circuit. Of the NAND gate, the output of the other NAND gate is supplied to the other input of the NAND gate, and the switching element turns on / off the power supply to the light emitting element according to the output of each NAND gate. Therefore, the flip-flop is raised by the abnormality detection signal output earliest and outputs an H level signal,
This inverts the output of the NAND gate to L level,
The light emitting element is turned on and the output of the NAND gate at the L level is given to the other input of the other NAND gate, so that the output of the other NAND gate becomes H.
This is achieved by configuring the level to be retained. Further, the above-mentioned object is that the display circuit has a light-emitting element connected to a constant voltage source, a thyristor connected to the light-emitting element, and a diode for backflow prevention branched on the anode side of the thyristor. Each output is connected to the gate of the thyristor, the anode side of each thyristor is connected to the gate side of another thyristor via the diode for backflow prevention, and the switching action of each thyristor turns on / off the power supply to the associated light emitting element. The thyristor is turned on by the abnormality detection signal output earliest, the light emitting element is turned on by the abnormality detection signal, and the anode side of the thyristor becomes L level. The gate of the other thyristor is held at the L level by being applied to the gate of It is achieved by the the As.

According to this invention, when an abnormal voltage occurs in any output of the power supply circuit, the abnormal voltage detection circuit corresponding to this output detects it and outputs an abnormality detection signal, which activates the protection circuit. And outputs the stop signal to the power supply circuit, and this abnormality detection signal is input to the display circuit, whereby only the light-emitting element related to the abnormality detection signal input earliest emits light to perform the emission display. Even if an abnormality detection signal is input to the other abnormal voltage detection circuit, the other light emitting elements do not emit light.Therefore, only the light emission display related to the output of the power supply circuit where the abnormal voltage occurs is displayed. Whether or not a voltage is generated can be easily confirmed, and a quick response can be taken to restart the power supply circuit in a short time.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings.

FIG. 1 shows an embodiment of an output abnormality detecting circuit according to the present invention. The output abnormality detecting circuit 10 is provided for a power supply circuit 11 having a plurality of outputs, in the illustrated case, three outputs 11a, 11b and 11c. , Their respective outputs 11a, 11b and 11c
And the abnormal voltage detection circuits 12, 13 and 14 connected to the respective terminals, and the outputs of the abnormal voltage detection circuits 12, 13 and 14 are collectively input to one common protection circuit 15 via backflow prevention diodes. This protection circuit 1
The output of 5 is input to a voltage control unit or the like (not shown) of the power supply circuit 11.

The above configuration has the conventional output abnormality detection circuit 1 shown in FIG.
However, in the output abnormality detecting circuit 10 according to the present invention, the abnormal voltage detecting circuits 12 and 13 are further provided.
16a, 16 connected to the outputs of 14 and 14, respectively
A display circuit 16 having b and 16c is provided.

The display circuit 16 includes the abnormal voltage detection circuits 12, 13,
14 corresponding to each output 11a, 1 of the power supply circuit 11.
1b and 11c corresponding to the light emitting elements 17a and 1a, respectively.
7b and 17c, and each light emitting element 17a, 17c
b and 17c are the abnormal voltage detection circuits 12, 13, 1
Based on the abnormality detection signal output first out of the abnormality detection signals from No. 4, the related light emitting elements 17a, 17b
Alternatively, even if only 17c is caused to emit light and then the abnormal voltage detection circuit 12, 13, 14 outputs an abnormal detection signal, the other light emitting element 17a, 17b or 17c does not emit light.

The output abnormality detection circuit 10 according to the present invention is configured as described above, and normally the outputs 11a, 11 of the power supply circuit 11 are provided.
Normal voltages are output from b and 11c, so that the abnormal voltage detection circuits 12, 13 and 14 do not operate,
Since the abnormality detection signal is not output from the output, the protection circuit 15 does not output the stop signal to the power supply circuit 11,
The power supply circuit 11 continues to operate as it is, and since no signal is input to the inputs 16a, 16b, 16c of the display circuit 16, the display circuit 16 does not operate, and therefore any of the light emitting elements 17a, 17b, 17c does not operate. Does not emit light.

Here, either output 11a, 11 of the power supply circuit 11
When an abnormal voltage occurs in b and 11c, the output 11a,
Abnormal voltage detection circuit 12 corresponding to 11b or 11c,
13 or 14 detects this and outputs an abnormality detection signal, whereby the protection circuit 15 operates and outputs a stop signal to the power supply circuit 11 to stop the power supply circuit 11, and at the same time, this abnormality detection signal is displayed. 16 inputs 16a, 1
The light emitting elements 17a, 17b which are input to 6b or 16c and are associated with the earliest input abnormality detection signal.
Alternatively, only one of 17c emits light to display the light emission, and thereafter, the other abnormal voltage detection circuits 12, 13,
Even if an abnormality detection signal is input to the display circuit 16 from 14, the other light emitting elements 17a, 17b and 17c do not emit light,
Outputs 11a and 11 of the power supply circuit 11 in which the abnormal voltage is generated
Only the light emission display for any one of b and 11c is performed, and any output 11a, 11b11c
It can be easily confirmed whether or not an abnormal voltage has occurred at.

FIG. 2 shows a specific configuration of the display circuit 16 shown in FIG. 1. In the display circuit 16, inputs 16a, 16b and 16c are connected to the CL input and a constant voltage source is connected to the D input. At the same time, the S input is grounded and the R input is connected to one reset terminal to three D-type flip-flops 21, 22 and 23, and to the Q outputs of the D-type flip-flops 21, 22, 23, respectively. Three NAND gates 24, 25 and 26 with one input connected
And the bases thereof are connected to the outputs of the NAND gates 24, 25 and 26 via resistors and the emitters thereof are connected to a constant voltage source via the resistors, and the collectors thereof are respectively connected to the light emitting elements 17a, 17b and 17c. It is composed of three transistors 27, 28 and 29 which are grounded. In addition, each NAND gate 24, 25, 2
The output of 6 is connected to the other input of another NAND gate.

According to the display circuit 16 configured as described above, a signal is not normally given to any input of the display circuit 16, so that the Q outputs of the D-type flip-flops 21, 22, 23 are all at the L level. , Nand Gate 24, 25, 26
The signal applied to one input of is at the L level, while the signals applied to the other inputs are at the H level,
The output is at H level, and each transistor 27, 2
An H-level signal is input to the bases of 8 and 29, and all the transistors 27, 28, and 29 are turned off, so that none of the light emitting elements 17a, 17b, and 17c emits light.

Here, for example, when the abnormal voltage detection circuit 12 detects an abnormal voltage, an abnormality detection signal is input to the input 16a of the main display circuit 16, whereby C of the D-type flip-flop 21 is input.
Since the rising signal is given to the L input, the signal from the Q output of the D-type flip-flop 21 is inverted from the L level to the H level, and the signals given to the three inputs of the NAND gate 24 are all brought to the H level. Therefore, the output of the NAND gate 24 is inverted to the L level, so that the L level signal is input to the base of the transistor 27, the transistor 27 is turned on, and the light emitting element 1
7a is turned on.

At that time, since the L-level signal of the NAND gate 24 is applied to the two input terminals of the other NAND gates 25 and 26, respectively, the other abnormal voltage detection circuit 13,
Even if 14 detects an abnormal voltage and a signal is given to the CL inputs of the D-type flip-flops 22 and 23 via the inputs 16b and 16c, and the Q outputs of the D-type flip-flops 22 and 23 are inverted to the H level. , Nand Gate 25,26
Output of the other light emitting element 17 is maintained at the H level.
b and 17c never light up.

Further, FIG. 3 shows a specific configuration example different from FIG. 2, and the display circuit 16 has inputs 16a, 16b and 16
c is connected to a gate via a resistor, the gate is grounded via a resistor, the cathode is grounded, and the anode is light-emitting elements 17a, 17 respectively.
It is composed of three thyristors 31, 32 and 33 connected to a constant voltage source via b and 17c. Further, the anode side of the thyristor 31 is connected to the gate sides of the other thyristors 32 and 33 via the backflow prevention diodes 41 and 42, and the anode side of the thyristor 32 has the backflow prevention diodes 43 and 44. Is connected to each gate side of the other thyristors 31 and 33, and the anode side of the thyristor 33 is connected to the backflow prevention diode 45,
Each gate side of the other thyristors 31 and 32 is connected via 46.

According to the display circuit 16 configured as described above, since no signal is normally given to its inputs 16a, 16b and 16c, no signal is input to the gates of the thyristors 31, 32 and 33, and therefore each thyristor is not. Although 31, 32, and 33 are off, the light emitting elements 17a, 17b, and 17c do not emit light, but when the abnormal voltage detection circuit 12 detects an abnormal voltage, for example, an abnormality detection signal is input to the input 16a of the display circuit 16. As a result, a signal is given to the gate of the thyristor 31, so that the thyristor 31 is turned on and the light emitting element 17a is turned on.

At that time, since the gates of the other thyristors 32 and 33 are connected to the anode side of the thyristor 31 via the diodes, respectively, the other abnormal voltage detection circuit 1 is subsequently provided.
Even if 3 and 14 detect an abnormal voltage and a signal is given to the gates of the thyristors 32 and 33 via the inputs 16b and 16c, the signals flow through the diodes to the anode side of the thyristor 31 and are further turned on. Since it escapes to the ground through the thyristor 31 of the other thyristor 32, 33
The gate of the other light emitting element 1 is held at the L level.
7b and 17c never light up.

[Effect of device]

As described above, according to the present invention, a plurality of abnormal voltage detection circuits each connected to each output of a power supply circuit having a plurality of outputs, and an abnormality detection signal from any one of the abnormal voltage detection circuits. In an output abnormality detection circuit including a common protection circuit that outputs a stop signal to the power supply circuit when input, a display circuit including a light emitting element corresponding to each abnormal voltage detection circuit is provided, Of the abnormality detection signals from the abnormal voltage detection circuit, based on the earliest output abnormality detection signal, only the output of the power supply circuit corresponding to the signal is lit up and displayed, preferably each abnormal voltage detection The output of the circuit is connected to the clock input of each flip-flop, and the output of the flip-flop is one of the NAND gates provided corresponding to each output of the power supply circuit. The output of the other NAND gate is given to the other input of the NAND gate, and the power supply to the light emitting element is turned on and off by the switching element according to the output of each NAND gate. The flip-flop is raised by the earliest output abnormality detection signal and outputs a signal of H level, whereby the output of the NAND gate is inverted to L level, the light emitting element is turned on, and the L level of the NAND gate is turned on. Is applied to the other input of the other NAND gate, the output of the other NAND gate is held at the H level, or the output of each abnormal voltage detection circuit is connected to the gate of the thyristor. , The anode of each thyristor is connected to a constant voltage source via a light emitting element, In addition, the anode side of each thyristor is connected to the gate side of another thyristor through a diode for preventing backflow, and the switching action of each thyristor is configured to turn on / off the power supply to the associated light emitting element, The earliest outputted abnormality detection signal turns on the thyristor, thereby turning on the light emitting element, and the anode side of the thyristor becomes L level,
By applying this to the gate of another thyristor, the gate of the other thyristor is configured to be held at the L level. Therefore, if an abnormal voltage occurs in any output of the power supply circuit, this output is handled. The abnormal voltage detection circuit detects this and outputs an abnormality detection signal, which activates the protection circuit and outputs a stop signal to the power supply circuit, and the abnormality detection signal is input to the display circuit. Only the light emitting element related to the abnormality detection signal input earlier emits light to display the light emission, and even if the abnormality detection signal is input from another abnormal voltage detection circuit thereafter, the other light emitting elements do not emit light. Only the light emission display regarding the output of the power supply circuit in which the abnormal voltage is generated is performed.

Therefore, it is possible to easily confirm in which output the abnormal voltage has occurred, and it is possible to quickly respond to this and restart the power supply circuit in a short time.

Thus, according to the present invention, in a power supply circuit having a plurality of outputs, when an abnormal voltage occurs in any output, the power supply circuit is stopped and at which output the abnormal voltage occurs. Therefore, it is possible to provide an extremely excellent output abnormality detection circuit that can be easily confirmed by the light emission display of the display circuit.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an output abnormality detecting circuit according to the present invention, FIG. 2 is a circuit diagram showing a concrete configuration of the output abnormality detecting circuit of FIG. 1, and FIG. FIG. 6 is a circuit diagram showing another configuration different from FIG. FIG. 4 is a block diagram showing an example of a conventional output abnormality detection circuit. 10 ... Output abnormality detection circuit; 11 ... Power supply circuit; 12,
13, 14 ... Abnormal voltage detection circuit; 15 ... Protection circuit;
16 ... Display circuit; 17a, 17b, 17c ... Light emitting element; 21, 22, 23 ... D flip-flop; 2
4, 25, 26 ... Nand gate; 27, 28, 29 ...
... transistors; 31, 32, 33 ... thyristors, 4
1, 42, 43, 44, 45, 46 ... Backflow prevention diode.

Claims (3)

[Scope of utility model registration request] 1. A plurality of abnormal voltage detection circuits respectively connected to respective outputs of a power supply circuit having a plurality of outputs, and the power supply circuit when an abnormality detection signal is inputted from any of the abnormal voltage detection circuits. In the output abnormality detection circuit that includes a common protection circuit that outputs a stop signal to, a display circuit including a light emitting element corresponding to each abnormal voltage detection circuit is provided, and an abnormality from the abnormal voltage detection circuit is provided. An output abnormality detection circuit, characterized in that, based on the abnormality detection signal that is output earliest among the detection signals, only the output of the power supply circuit corresponding to the abnormality detection signal is lit and displayed. 2. The display circuit comprises a flip-flop in which an output of each of the abnormal voltage detection circuits is connected to a clock input, a NAND gate in which each output of the flip-flop is connected to one input, and an output of the NAND gate. 2. A switching element for turning on / off power supply to a light emitting element according to claim 1, wherein an output of the NAND gate is connected to another input different from the one input of the other NAND gate. Output abnormality detection circuit described in the item. 3. The display circuit includes a light emitting element connected to a constant voltage source, a thyristor connected to the light emitting element, and a backflow preventing diode branched on the anode side of the thyristor. The output of the abnormality detection circuit is connected to the gate of each thyristor, and the anode side of the thyristor is connected to the gate side of another thyristor via a diode for preventing backflow. The output abnormality detection circuit according to item 1.