JPH05316060A - Voltage monitor circuit for communication equipment - Google Patents

Abstract

PURPOSE:To attain preventive and scheduled equipment maintenance against a fault of equipment by visually indicating a voltage fluctuation even when a monitored voltage exceeds a normal voltage range but does not reach a level for occurrence of warning. CONSTITUTION:A voltage of reference power supplies 2, 3 in a voltage monitor circuit 20 is set to an upper limit and a lower limit in a 1st voltage range for warning setting and when an input voltage at an input terminal (monitored voltage) does not exceed the 1st voltage range, a green light emitting diode D2 is lighted and when exceeding, the diode goes off. Moreover, a voltage of reference power supplies 6, 7 in a voltage monitor circuit 21 is set to an upper limit and a lower limit in a 2nd voltage range for normal setting and when an input voltage at an input terminal (monitored voltage) does not exceed the 2nd voltage range, a red light emitting diode D2 goes off and when exceeding, the diode is lighted. When the monitored voltage exceeds the 2nd voltage range but does not exceed the 1st voltage range, the green light emitting diode D1 and the red light emitting diode D2 are both lighted in orange.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device voltage monitoring circuit for a wireless or wired system.

[0002]

2. Description of the Related Art FIG. 2 is a circuit diagram showing a configuration example of a conventional voltage monitoring circuit for communication equipment. This circuit has an input terminal 10
Input voltage (monitored voltage) exceeds the preset voltage range (for example, 5V ± 20%) (upper limit value 5V + 20%)
If higher, or if) be lower than the lower limit 5V-20%, considered as the voltage value is abnormal, and turns on the red light-emitting diode D _3.

That is, the comparator circuit IC ₅ outputs (open collector) when the monitored voltage is lower than the voltage of the reference power source 11 (which is set to the upper limit voltage of the set voltage range and is set to 6 V in this circuit). Output) is open,
It is a circuit that operates so that the output is grounded when the monitored voltage is higher than the voltage of the reference power supply 11. Also, comparison circuit IC
₆ indicates that the output (open collector output) is opened when the monitored voltage is higher than the voltage of the reference power supply 12 (the lower limit voltage of the setting voltage range, which is set to 4 V in this circuit), It is a circuit that operates so that the output is grounded when the monitored voltage is lower than the voltage of the reference power supply 12.

Since the output terminals of the above-mentioned comparison circuits IC ₅ and IC ₆ are wired or connected, the comparison circuit IC
When the output of ₅ or IC ₆ is grounded, point A is also grounded. At this time, a current flows from the positive power source input terminal 13 to the point A via the current limiting resistor R ₁₉ and the light emitting diode D ₃ to light the light emitting diode D ₃ . When both outputs of the comparison circuits IC ₅ and IC ₆ are open, the point A is also open and the light emitting diode D ₃ is turned off.

Therefore, the lighting state of the red light emitting diode D _{3 with} respect to the monitored voltage is classified as shown in Table 1.

[0006]

[Table 1]

[0007]

In the above-mentioned conventional voltage monitoring circuit for communication equipment, the monitored voltage is within the set voltage range of 5V.
Unless it deviates from ± 20%, the red light emitting diode D ₃ does not light up. However, normally, even if the monitored voltage is within the set voltage range, the voltage range for normal operation (for example, 5 V ± 10
%) Often want to monitor whether or not. In such a case, the conventional circuit has a drawback in that it cannot detect whether the monitored voltage is within the normal voltage range, preventing the device failure and preventing the planned maintenance of the device.

[0008]

A voltage monitoring circuit for communication equipment according to the present invention is a first voltage monitoring circuit for monitoring whether or not a monitored voltage is within a first voltage range set for alarming. A second voltage monitoring circuit for monitoring whether or not the monitored voltage is within a second voltage range set so as to be included in the first voltage monitoring range; and the first and second voltage monitoring circuits. And a multicolor light emitting diode circuit that emits multicolor light in response to the lighting control electric signal in response to the monitoring result of the voltage monitoring circuit.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a circuit diagram showing an embodiment of the present invention. In the circuit of this embodiment, when the input voltage (monitored voltage) of the input terminal 1 is within the normal voltage range (for example, 5V ± 10%), the multicolor light emitting diode circuit 23 is lit in green and normal If it exceeds the current voltage range but is within the alarm setting voltage range (for example, 5V ± 20%), the multicolor light emitting diode circuit 23 is lit in orange. Further, when the monitored voltage exceeds the alarm set voltage range (5V ± 20%), the multicolor light emitting diode circuit 23 is turned on in red.

The operation will be described below.

The voltage monitoring circuit 20 is the same circuit as the voltage monitoring circuit 24 of FIG. 2 and operates in the same manner. Therefore,
The potential at point B corresponding to the monitored voltage is the same as the potential at point A in FIG. 2, which can be classified as shown in Table 2.

[0013]

[Table 2]

The voltage monitoring circuit 21 is the same circuit as the voltage monitoring circuit 24 of FIG. 2, but the voltage of the reference power source 6 (which is set to the condition voltage within the normal voltage range, and is 5.5 V in this embodiment). Set to the lower limit voltage of the normal voltage range, which is set to 4.
5V) is different from the case of FIG. That is, the voltage monitoring circuit 21 operates in the same manner as the voltage monitoring circuit 24 of FIG. 2, and only the monitored voltage range is different. Therefore, the potential at the point C corresponding to the monitored voltage can be classified as shown in Table 3.

[0015]

[Table 3]

The drive circuit 22 controls to turn on or off the red light emitting diode D ₁ and the green light emitting diode D ₂ of the multicolor light emitting diode circuit 23 according to the potentials at the points B and C. That is, in the transistor TR ₁ of the drive circuit 22, the base potential becomes a forward bias voltage due to the pull-up resistor R ₉ when the point B is open, so that the collector-emitter becomes conductive. At this time, the voltage of the positive power supply input terminal 4 causes the current limiting resistor R ₁₁ ,
A current flows to the ground point between the collector and the emitter of the transistor TR ₁ and via the green light emitting diode D _2, and the green light emitting diode D ₂ is lit by this current. or,
When the point B is ground-faulted, the base potential becomes a reverse bias voltage and the transistor TR _{1 has} a collector-emitter open state. Therefore, the green light emitting diode D ₂
Turns off.

The transistor TR ₂ of the drive circuit 22 is C
When the point is ground-faulted, the base potential becomes a forward bias voltage, so that the collector and emitter become conductive. At this time, the voltage of the positive power supply input terminal 4 causes the current limiting resistor R
₁₀ , a current flows between the collector and the emitter of the transistor TR ₂ and the ground via the red light emitting diode D _1, and the red light emitting diode D ₁ is lit by this current. When the point C is open, the base potential becomes a reverse bias voltage, and the collector-emitter of the transistor TR ₂ is open. Therefore, the red light emitting diode D ₁ is turned off.

In the multicolor light emitting diode circuit 23, when the red light emitting diode D ₁ and the green light emitting diode D ₂ are simultaneously lit, the lighting colors of the two are combined and lit in orange. That is, the multicolor light emitting diode circuit 23 lights up in any one of green, orange, and red colors depending on the combination of the lighting states of the red light emitting diode D ₁ and the green light emitting diode D ₂ . Therefore, the lighting color of the multicolor light emitting diode circuit 23 corresponding to the monitored voltage can be classified as shown in Table 4.

[0019]

[Table 4]

[0020]

As described above, according to the present invention, the multicolor light emitting diode is turned on even when the monitored voltage value exceeds the normal voltage range, but the monitored voltage value does not exceed the alarm set voltage range. It is possible to check the voltage fluctuations of the device automatically and more precisely than before, and prevent device failures and perform planned maintenance of the device.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram of a conventional circuit.

[Explanation of symbols]

 1,10 (monitored voltage) input terminal 2,3,6,7,11,12 reference power supply 4,5,8,9,13,14 positive power supply input terminal 20,21 voltage monitoring circuit 22 drive circuit 23 multicolor Light emitting diode

Claims (1)

[Claims] 1. A first voltage monitoring circuit for monitoring whether a monitored voltage is within a first voltage range set for an alarm, and the monitored voltage is within the first voltage monitoring range. A second voltage monitoring circuit for monitoring whether or not the voltage is within a second voltage range set to be included in the first voltage monitoring circuit, and for controlling lighting in response to the monitoring results of the first and second voltage monitoring circuits. A voltage monitoring circuit for a communication device, comprising: a drive circuit that emits an electric signal; and a multicolor light emitting diode circuit that lights in multiple colors according to the lighting control electric signal.