KR19980029195A - Power monitor - Google Patents

Abstract

The present invention relates to a power monitoring device that monitors whether the power supplied to the system maintains a normal level voltage and displays whether the power supply is normal. A supervisory power input unit for applying, a supervisory power supply unit for determining whether the power supply is normal according to the configuration of the bypass element by receiving the output of the supervisory power supply unit, and the normality of the power determined by the supervisory unit It is characterized in that it comprises an alarm display unit for indicating whether or not to maintain a constant voltage unchanged even in the slight fluctuations of the power supplied to the system, and in the case of a power failure to prevent the main clock of the system to continue abnormal data processing Let's go.

Description

Power monitor

The present invention relates to a power supply monitoring apparatus, and more particularly, to a power supply monitoring apparatus configured to monitor whether a power supplied to a system maintains a normal level voltage and to indicate whether the power supply is normal.

In general, a widely used technique for power monitoring has mainly been made by making a comparison circuit using a relay element and a simple OP-AMP.

This circuit configuration has the problem of ignoring small variations in the input power to be monitored and monitoring only two extreme cases, such as 'high' (eg + 5V) or 'low' (eg ground level).

In addition, devices such as relays have a poor durability, so there is a problem that is very unsuitable to apply to a circuit.

Accordingly, the present invention has been made in view of the above-described circumstances, and an object thereof is to provide a power supply monitoring device that compares and monitors a power supply voltage by using an output voltage according to a voltage change of a photocoupler, and indicates whether the power supply is normal. have.

1 is a schematic structural block diagram of a power monitoring apparatus according to the present invention;

FIG. 2 is a detailed configuration diagram of the power monitoring device of FIG. 1. FIG.

3 is a signal waveform diagram for explaining the operation of FIG.

* Explanation of symbols for main parts of the drawings

11: monitoring power input unit 12: power monitoring unit

13: alarm display unit 101: rectifier

102: photo coupler 201: judgment unit

301: light emitting diodes C1, C2, C3: capacitor

Power monitoring apparatus according to the present invention for achieving the above object is a monitoring power input unit for applying a power to be monitored without an external input from the outside, by-pass (by-pass) elements receiving the output of the monitoring power input unit; According to the configuration of the power supply monitoring unit for determining whether it is a normal power, and the alarm display unit for displaying whether or not the power is determined normal in the power monitoring unit.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

1 is a schematic block diagram of a power monitoring apparatus according to the present invention, wherein reference numeral 11 is a monitoring power input unit for applying power to be monitored without a separate input from the outside, and 12 is the monitoring power input unit 11. A power monitoring unit for determining whether the power is normal according to the configuration with the bypass element by receiving the output of the power, 13 is an alarm display unit for displaying whether or not the power determined by the power monitoring unit 12 is normal to be.

FIG. 2 is a detailed configuration diagram of the power monitoring device of FIG. 1.

Reference numeral 101 is a rectifier for rectifying a current between the first system power supply voltage (+ 15V) and the second system power supply (-15V), 102 is connected in parallel to the rectifier 101, the first side to the anode side The photo coupler receives the system power (+ 15V), the cathode side is connected to the second system power (-15V), and the collector side receives the power (+ 5V) to be monitored and outputs it to the emitter side.

The rectifier 101 receives a first system power (+ 15V) to the anode side, and a first diode D1 having a cathode side grounded, a second diode D2 having a anode side grounded, and an anode side having the second side. And a third diode D3 connected to the cathode side of the diode D2 and receiving a second system power supply -15V to the cathode side.

Reference numeral C1 denotes a first capacitor to which one side is grounded and a supervisory power supply (+ 5v) is applied to the other side, C2 denotes a capacitor to which one side is grounded, C3 denotes a second capacitor to which one side is grounded, and reference numeral 201 denotes the photo coupler 102. ), The SENSE terminal is connected to the other side of the first capacitor C1, the REF terminal is connected to the other side of the capacitor C2, and the CT terminal is connected to the second capacitor C3. The determination unit 301 connected to the other side of the control unit 301 is a light emitting diode which is turned on according to a signal output from the / RESET terminal of the determination unit 201.

Now, the operation of the power monitoring apparatus according to the present invention configured as described above will be described in detail with reference to FIG.

First, the monitoring power input unit 11 receives the input side of the photo coupler 102 as a closed circuit, and the anode side receives the first system power supply (+ 15V) and the cathode side receives the second system power supply (-15V). By setting the level to the ground level, a potential difference (i.e., 0.4V on the anode side and -0.8V on the cathode side) is generated between the anode side and the cathode side to allow current to flow.

If either one of the first or second system power supply (+ 15V / -15V) is not supplied, current flows continuously due to the ground applied in the middle of the photo coupler 102.

As described above, a power source (+ 5V) that requires monitoring is continuously output to the emitter of the photo coupler 102 while the current is continuously flowing.

Accordingly, the determination unit 201 receives + 5V, which is the output of the photo coupler 102, to the / RESIN terminal as shown in FIG. 3 (a), and + 5V to the SENSE terminal as shown in FIG. 3 (b). In order to reduce the effect of the fast conversion from 'low' to 'high' and 'high' to 'low' according to the voltage fluctuation of the input supervisory power input, it is generally used in FIG. As in (c), fix it so that + 2.5V is maintained at REF terminal.

And, the original / RESET output is to be generated after CT value from the threshold voltage of SENSE. The input voltage was 3V.

At this time, if the monitoring power is normal according to the input condition of the / RESIN and SENSE terminals and the condition of the peripheral circuit, 'high' (+ 5V) is sent from the / RESET terminal of the determination unit 201 to the alarm display unit 13. do.

When the alarm display unit 13 receives + 5V, such as the monitoring power supply (+ 5V) supplied to the collector side of the photo coupler 102, the alarm display unit 13 operates the light emitting diode 301 indicating the steady state display.

The output signal of the / RESET terminal of the determination unit 201 may be a normal power supply. However, when the monitoring power supply is in a bad state as shown in (a) of FIG. The / RESET signal, which is generated after t _pd (typically 1.5μsec), stops the entire system operation, such as the clock.

Therefore, according to the present invention configured and operated as described above, a constant voltage is maintained without change even in the slightest fluctuation of the power supplied to the system, and in case of a power failure, the main clock of the system is prevented from continuing abnormal data processing. do.

Claims (5)

A monitoring power input unit for applying power to be monitored without an external input from the outside, a power monitoring unit determining whether the power is normal according to the configuration with the bypass elements by receiving the output of the monitoring power input unit; And an alarm display unit for displaying whether the power determined by the power monitoring unit is normal. The method of claim 1, wherein the monitoring power input unit is connected to a rectifier for rectifying a current between a first system power supply voltage and a second system power supply, and the rectifying unit in parallel, and receives the first system power supply to an anode side. The cathode side is connected to the second system power source, and the collector side comprises a photo coupler for receiving the power to be monitored and output to the emitter side. The output terminal of claim 1, wherein the power monitoring unit has a first capacitor grounded at one side and a supervisory power applied to the other side, a capacitor at one side grounded, a second capacitor grounded at one side, and an output of the monitoring power input unit. And a judgment unit connected to the other side of the first capacitor, the REF terminal connected to the other side of the capacitor, and the CT terminal connected to the other side of the second capacitor. Device. The power monitoring device of claim 3, wherein the alarm display unit comprises a light emitting diode configured to be turned on according to a signal output from the / RESET terminal of the determination unit. The cathode of claim 2, wherein the rectifier receives a first system power to the anode side, the first diode having the cathode side grounded, the second diode having the anode side grounded, and the anode side connected with the cathode side of the second diode. And a third diode configured to receive a second system power source to the cathode side.