JPH01278255A - Power source - Google Patents

Abstract

PURPOSE:To exclude judgement of an erroneous trouble by detecting the momentary power interruption malfunction of an input AC power source, and delaying an input power source ON signal for a predetermined period of time by a delay circuit. CONSTITUTION:An input AC power source 11 is rectified by a rectifying diode stack 14 through a noise filter 12 and a circuit breaker 13. It is then smoothed by a large capacity capacitor 16, stabilized by a DC/DC converter 17 and output. In this case, an auxiliary contact switch 21 is connected to the breaker 13, opened when the power source 11 is turned ON and closed at the time of power interruption. An insufficient input voltage detector 27, an abnormal detection inhibitor 38, a delay circuit 52, and an input momentary power interruption display circuit 54 are provided. Thus, the detector 27 outputs of the momentary power interruption malfunction signal of the power source 11, the switch 21 outputs an input power source ON signal by the closure upon energization of the power source, it is delayed by the circuit 52, and output. The detection signal is output and displayed by the malfunction signal and the delayed energization signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power supply device, and more particularly to a power supply device having a function of detecting and displaying a momentary power outage abnormality in a human power source.

[Conventional technology]

FIG. 2 shows a conventional power supply device of this type.

In the figure, a human AC power supply 11 passes through a noise filter 12 and a circuit breaker 13 and is rectified by a rectifier diode stack 14 . And large capacity aluminum electrolytic capacitor 16
The voltage is smoothed by the DC-DC converter 17, and outputted to the output terminal 18 as a stabilized DC voltage.

[Problem to be solved by the invention]

However, in such a conventional power supply device, there is a problem in that if the human power supply is momentarily cut off for a predetermined period of time or more, the output of the capacitor 16 decreases, making it impossible to supply a stable DC voltage to the load of the device. Also in this case,
An output undervoltage detection circuit of the power supply device (not shown) is activated, lights up a power failure indicator lamp (not shown), and the operation of the power supply device is stopped. Therefore, when a maintenance person sees the power supply abnormality indicator lamp lit, he or she determines that the power supply device is abnormal.

The power supply device was then returned to the factory and investigated by the inspection department, but the cause was determined to be unknown, and as a result, non-reproducible products could not be easily shipped, resulting in the problem of unreproduced products accumulating at the factory.

Therefore, an object of the present invention is to prohibit the detection of an insufficient charge state of the capacitor immediately after the input power is turned on, and to detect and display a momentary interruption of the input power for a certain period of time while the power is turned on. An object of the present invention is to provide a power supply device having a function of identifying failures and instantaneous power outages.

[Means to solve the problem]

The power supply device of the present invention includes a circuit breaker that turns on and cuts off a human-powered AC power supply, a rectifier circuit that rectifies the human-powered AC voltage, a smoothing circuit that smoothes this rectified voltage, and a circuit breaker that turns on and cuts off a human-powered AC power source. A device consisting of a DC-DC converter that converts into a stabilized DC voltage, detects a drop in the voltage across the smoothing circuit caused by a momentary interruption of the human-powered AC power supply, and generates a momentary interruption abnormality signal indicating an abnormal momentary interruption. an input undervoltage detection circuit that outputs an input undervoltage; an auxiliary contact switch means that is connected to the circuit breaker and is opened when the manual AC power is turned on and closed when the manual AC power is shut off; A delay circuit that delays a manual power-on signal indicating opening of the auxiliary contact switch means for a certain period of time when the power is turned on, and outputs the delayed input power-on signal, and a delay circuit that is connected to the input undervoltage detection circuit. , an abnormality detection prohibition circuit that receives the instantaneous power failure abnormality signal from the human power shortage voltage detection circuit and the delayed input power supply turn-on signal from the delay circuit, and outputs the instantaneous power failure abnormality detection signal; A human power instantaneous power interruption display circuit connected to the circuit and reset by the closing of the auxiliary contact switch means when the input AC power is turned on, and that receives and displays a momentary power interruption abnormality signal from the human power insufficient voltage detection circuit. are doing.

Therefore, when the power supply device according to the present invention is used, the undervoltage detection circuit connected to both ends of the smoothing circuit outputs a momentary power failure abnormality signal indicating a momentary power failure abnormality in the input AC power supply, and the auxiliary contact connected to the circuit breaker The switch means outputs an input power-on signal by closing the circuit when the input AC power is turned on, and the delay circuit delays this and outputs the delayed input power-on signal. Then, the abnormality detection prohibition circuit receives the instantaneous power interruption abnormality signal and the delayed input AC power supply turn-on signal, and outputs the instantaneous interruption abnormality detection signal. Further, the human power instantaneous power failure display circuit receives the instantaneous power failure abnormality signal and displays the instantaneous power failure abnormality of the power supply device. Therefore, even if the output of the power supply device decreases due to a momentary power outage or the like, it can be prevented from being erroneously determined to be a failure.

〔Example〕

The present invention will be explained in detail with reference to Examples below.

FIG. 1 shows the power supply device of this embodiment. Second
The same parts as in the conventional example shown in the figure are given the same reference numerals, and the explanation thereof will be omitted as appropriate.

In the figure, an auxiliary contact switch 21 is connected to the circuit breaker 13. The auxiliary contact switch 21 is configured to open when the input AC power source 1l is turned on, and close when the input AC power source 1l is turned off.

First, when the circuit breaker 13 is turned on, the human-powered AC voltage 22 from the human-powered AC power source 11 is rectified by the rectifier circuit 14 and smoothed by the large-capacity aluminum electrolytic capacitor that is the smoothing circuit 16 to become a smoothed voltage 24. . And furthermore, DC-DC
It is converted into a stabilized DC voltage 25 by the converter 17 and output from the output terminal 18 .

Here, if a momentary interruption occurs in the input AC power supply 11 for some reason, the voltage across the large capacity aluminum electrolytic capacitor 16 decreases. If this instantaneous interruption continues for more than a specified time, the voltage across the large-capacity aluminum electrolytic capacitor 16 becomes less than the specified value. Therefore, the DC-DC converter 17 cannot maintain the stabilized DC output voltage, and the stabilized DC voltage 25
decreases. Then, the protection circuit inside the DC-DC converter 17 is activated, stopping the operation of the DC-DC converter 17 and stopping the output supply.

As explained above, in the conventional system, when the power failure indicator lamp lights up and the device operation stops, it is determined that a failure has occurred, but in the present invention, as will be explained next, the input AC This can be determined to be a momentary power outage.

That is, the voltage drop across the large capacity aluminum electrolytic capacitor 16 is detected by the input undervoltage detection circuit 27 connected thereto. This undervoltage detection circuit 27 is composed of first and second transistors 30 and 31 forming a differential pair. These first and second transistors 30.3
The emitter of No. 1 is directly connected to the positive electrode of a large capacity aluminum electrolytic capacitor 16 through a resistor 32 . The base of the second transistor 31 is connected to the positive electrode of the large capacity aluminum electrolytic capacitor 16 through a variable resistor 34 . Furthermore, the second
The collector of the transistor 31 is connected to a photocoupler 36, and the output of the photocoupler 36 is connected to an abnormality detection prohibition circuit 38 at the next stage. Input undervoltage detection circuit 2
7, under normal conditions, the first transistor 30 is conductive and the second transistor 31 is non-conductive. As described above,
The voltage across the large capacity aluminum electrolytic capacitor 16 decreases,
When the voltage falls below the value set by the variable resistor 34, the base-collector voltage of the second transistor 31 decreases.
The second transistor 31 becomes conductive. Therefore, the photocoupler 36 also becomes conductive and sends a momentary interruption abnormality signal 40 at the "L" level to the abnormality detection prohibition circuit 38.

The abnormality detection prohibition circuit 38 configures a noise filter 45 with resistors 42, 43 and a capacitor 44, and removes unnecessary noise. Further, a one-man powered NAND gate 46 is provided, and when the input to this gate is at the "L" level, an output of "H" level is provided. Furthermore, a two-man powered NAND gate 49 is provided at the subsequent stage of this one-man powered NAND gate 47. Abnormality detection is prohibited. The "L" level instantaneous interruption abnormal signal 40 input to the circuit 38 is
The one-man powered NAND gate 46 sets it to "H" level, and the signal is input to one of the two-man powered NAND gates 49. The other human power of this two-man power NAND gate 49 is connected to a delay circuit 52, which will be described next. The output of this two-man power NAND gate 49 is connected to a set terminal 57 of a flip-flop IC 56 of an input interruption display circuit 54, which will be described later.

Furthermore, this abnormality detection prohibition circuit 38 includes a reset terminal 58 of the flip 70 and the tube rc 56 of the input instantaneous interruption display circuit 54.
A single-power NAND gate 64 is provided in which the output is connected to the auxiliary contact switch 21 of the circuit breaker 13 through a filter of resistors 60 and 61 and a capacitor 62. This operates to reset the input interruption indicator circuit 54.

Now, the delay circuit 52 delays the power-on signal 65 indicating the opening of the auxiliary contact switch 21 when the circuit breaker 13 is turned on, and delays the power-on signal 65 that indicates the opening of the auxiliary contact switch 21 when the circuit breaker 13 is turned on.
It operates so as not to detect the insufficient state of charging voltage in step 6.

That is, when the power-on signal 65 is sent to this delay circuit 52 at "H" level, the voltage of the capacitor 69 determined by the time constant of the resistor 67, 68 and the capacitor 69 becomes the reference voltage value determined by the resistor 71, 72. If it exceeds
The output of the comparator 74 becomes "H" level, thereby canceling the prohibition of abnormality detection. In this way, instantaneous power outage detection becomes possible while the power is turned on.

The abnormality detection prohibition circuit 3802 and the manual NAND gate 49 are
When an abnormality is detected after receiving the "H" level abnormality detection prohibition release signal 76 from the delay circuit 52 at the other terminal, that is, when receiving the instantaneous interruption abnormality signal 40 at one terminal as described above, A momentary power failure abnormality detection signal 7 is sent to the set terminal 57 of the flip-flop IC 56 of the human power momentary power failure display circuit 54.
Sends 7. This flip-flop IC 56 operates when the power is cut off, that is, when the auxiliary contact switch 21
When the circuit is closed, the "L" level power-on signal 65 is received at the reset terminal 58 through the one-handed AND gate 64 of the abnormality detection prohibition circuit 38, so that the instantaneous interruption abnormality detection signal 77 is not received. However, when the power is turned on and the auxiliary contact switch 21 is closed, the power-on signal 65 goes to "H" level and is manually input to the reset terminal 58, so the instantaneous interruption abnormality detection signal 77 cannot be received. You will be able to do this. Then, when the "L" level instantaneous interruption abnormality detection signal 77 is input to the set terminal 57, the output terminal 7
9 becomes “L” level, and the next stage solo A that receives this
The output 81 of the ND gate 80 goes to the "L" level, the light emitting diode 82 lights up, and a momentary interruption abnormality is displayed.

Incidentally, a battery 83 is used as a power source for the abnormality detection prohibition circuit 38, the input instantaneous power failure display circuit 54, and the delay circuit 52, but this is so that the device can operate reliably and display an abnormality even in the event of an input power failure. This is to do so.

〔Effect of the invention〕

As described above, in the power supply device of the present invention, the human power shortage voltage detection circuit detects a momentary power failure abnormality in the input AC power supply and outputs a momentary power failure abnormality signal, and the auxiliary contact switch outputs an input power supply turn-on signal. After the delay circuit delays the power-on signal for a certain period of time and eliminates the influence of the initial charging shortage of the smoothing circuit, it outputs the delayed input power-on signal. By outputting the instantaneous power failure abnormality detection signal and having the human-powered instantaneous power failure display circuit that receives the signal display the instantaneous power failure abnormality, it is possible to eliminate the possibility that the power supply device is erroneously determined to be malfunctioning. Therefore, in the subsequent restoration work, it is possible to eliminate unnecessary labor such as replacing the power supply device by mistake, increasing the number of man-hours for factory repairs, and disposing of inventory of undeliverable items.

[Brief explanation of the drawing]

FIG. 1 is a partial block circuit diagram showing an embodiment of a power supply device according to the present invention, and FIG. 2 is a block diagram showing a conventional power supply device. 11... Input AC power supply, 13... Breaker, 14... Rectifier circuit, 16... Smoothing circuit, 17... DC- DC converter, 21...
...Auxiliary contact switch, 27...Input undervoltage detection circuit, 38...
... Abnormality detection prohibition circuit, 52 ... Delay circuit, 54 ... Human power interruption display circuit.

Claims (1)

[Scope of Claims] A circuit breaker that turns on and cuts off input AC power, a rectifier circuit that rectifies input AC voltage, a smoothing circuit that smoothes this rectified voltage, and a circuit breaker that stabilizes this smoothed voltage. In a power supply device configured with a DC-DC converter that converts a DC voltage into a DC voltage, the power supply device is connected to both ends of the smoothing circuit, detects a drop in voltage across the smoothing circuit, and generates a momentary interruption abnormality signal indicating a momentary interruption abnormality. It is connected to the input undervoltage detection circuit to output and the circuit breaker, and is opened when the input AC power is turned on;
Auxiliary contact switch means that is closed when the input AC power is turned off; and an input AC power-on signal that is connected to the auxiliary contact switch means and indicates that the auxiliary contact switch means is opened when the input power is turned on, and is delayed by a certain period of time. a delay circuit that outputs an input AC power-on signal; and a delay circuit that is connected to the input undervoltage detection circuit,
an abnormality detection prohibition circuit that receives a momentary power failure abnormality signal from the input undervoltage detection circuit and a delayed input AC power supply turn-on signal from the delay circuit, and outputs a momentary power failure abnormality detection signal; an input instantaneous interruption display circuit that is connected to the circuit, is reset by closing of the auxiliary contact switch means when the input AC power is turned on, and receives and displays an instantaneous interruption abnormality signal from the input undervoltage detection circuit. A power supply device characterized by: