JPH0424839B2 - - Google Patents

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention is a device for detecting circuit abnormalities in neon tubes, neon transformers, etc. of neon tube lighting circuits equipped with a switching circuit for controlling blinking of neon tubes. Regarding.

``Prior Art'' In general, neon tube lighting circuits are designed to detect circuit abnormalities in neon tubes, neon transformers, etc., as seen in, for example, Japanese Utility Model Publications No. 39-5555 and Publication No. 16074-1980, etc. Each neon transformer is equipped with one set of load abnormality detection devices, such as overcurrent detection devices or undervoltage detection devices, to detect abnormalities in the load circuit.

``Problems to be Solved by the Invention'' Recent neon tube lighting circuits are becoming larger in size as information technology progresses. As a result, neon tube lighting circuits have become more complex, and the need for a load circuit abnormality detection device has increased. Against this background, as in the past, one neon transformer was
Equipped with a set of load circuit abnormality detection devices,
The cost of materials and construction increases as the scale of the neon tube lighting circuit increases, making it extremely uneconomical. In addition, in order to be able to easily identify abnormalities in neon tube lighting circuits that are becoming larger, it is necessary to install the display section all at once on a distribution board, etc., away from the neon tower, which requires a large amount of wiring. Moreover, wiring work has also increased and become more complicated, and the wiring has had disadvantages such as taking up a large amount of space.

The present invention provides means for solving the above problems.

"Means for solving the problem" A means for individually opening and closing the circuits connected to the power supply of the neon transformer, a means for detecting the input voltage in the power supply unit, and a circuit connected to the power supply of the neon transformer. Means for detecting the input current flowing from the power supply to each neon transformer by individually opening and closing the power supply unit, a storage means for pre-memorizing the range of input current values corresponding to each neon transformer, and the input current. A neon tube consisting of a neon transformer that reads out a value range, corrects the input current value range in response to the detected input voltage fluctuation, and compares it with the detected input current value, and that is outside the corrected range. A means for determining that the lighting circuit is abnormal is provided.

Embodiment FIG. 1 is a circuit configuration diagram of an embodiment of the present invention, which includes five neon tube lighting circuits. 10 ₁ ~
10 ₅ is a neon tube, the electrodes of which are connected to the secondary output terminals of neon transformers 9 ₁ to 9 ₅ , respectively. The primary input terminals of neon transformers 9 ₁ to 9 ₅ are all connected to power supply 1 . Reference numeral 2 denotes a current detection transformer that detects current from the output section of the power source 1 and converts it into an electrical signal. The input interface 3 is a circuit that A/D converts the electrical signal from the current detection transformer 2 and converts it into a digital signal. The digital signal is sent to the control circuit 4. The control circuit 4 includes a microcomputer 5 and a memory circuit 6, and the memory circuit 6 stores an upper limit value _B1U to _B5U of the primary input current of the neon transformer when a normal neon tube is lit. and lower limit values B _1D to B _5D are stored. A digital signal output from the control circuit 4 is sent to an output interface 7 and converted into an electrical signal, one of which is sent to an external output display circuit 12 and the other to a switching circuit 8. Inside the switching circuit 8, as shown in Fig. 2, there is a solid state relay (hereinafter referred to as SSR).
The load contact terminals 11 ₁ to _{11 5} are connected to the neon transformer 9
₁ to 9 ₅ are connected in series to one side of the primary input power supply lines. The electrical signal line from the output interface 7 is connected to the signal input terminal of the SSR, and the signal opens and closes the load contacts to connect the neon transformers 9 ₁ to 9.
9 Controls the NO/OFF of the primary input power to ₅ .

Now, the operation will be explained next. Control circuit 4
A flowchart for executing the control is shown in FIG. In the figure, P ₁ to _{P 16} indicate each step of the flowchart.

_P2 sets circuit number n to 0. At P ₃ , add 1 to n and set n to 1. At _P4 , a digital signal for lighting the neon tube ₁₀₁ is output from the control circuit 4 to the output interface 7. The digital signal input to the output interface 7 is converted into an electrical signal and output to the switching circuit 8.
In the switching circuit 8, the load contact terminal of only the SSR ₁₁₁ is turned ON by the electric signal from the output interface 7, and only the neon transformer ₉₁ is connected to the power supply, and only the neon tube ₁₀₁ is lit.
The input current at that time is detected by the current detection circuit 2, converted to a digital signal by the input interface 3,
At _P5 , the control circuit 4 reads the input current value _A1 when only the neon tube ₁₀₁ is lit. At _P6 , the microcomputer 5 reads the appropriate current upper limit value _B1U from the memory circuit 6, and at _P7 compares it with the measured input current value _A1 . When the input current value A ₁ is larger than the appropriate current upper limit value B _1U , it is determined that the circuit is abnormal in P ₈ and the abnormal circuit number n=1 is sent to the storage circuit 6 and stored. Otherwise, the microcomputer 5 reads the appropriate current lower limit value _B1D from the memory circuit 6 at _P9 , and compares it with the input current value _A1 at _P10 . When the input current value A ₁ is smaller than the appropriate current lower limit value B _1D , it is determined that the circuit is abnormal in P ₁₁ , and the abnormal circuit number n =
1 is sent to the memory circuit and stored. At other times, it is determined at _P12 that the circuit for lighting the neon tube ₁₀₁ is normal. Next, in P ₁₅ , since n is smaller than 5, which is the number of neon tube lighting circuits in this example,
Returning to _P3 , the steps _P3 to _P15 described above are repeated four times in this embodiment. Then, at P ₁₆ , memory circuit 6
The microcomputer 5 reads out the abnormal circuit number within and outputs it to the output interface 7. The signal is output to the external output display circuit 12, and the abnormal circuit number is displayed. After that, the program moves to the next control program for blinking, etc.

In step _P5 , the voltage detection circuit 13 detects the input voltage at that time, the input interface 3 converts it into a digital signal, and the control circuit 4 also reads the input voltage value. If the voltage value fluctuates, the appropriate current value range is corrected in response to the increase or decrease. That is, for example, when the input voltage increases, the appropriate current upper and lower limits (B _oU and step _P7 for circuit number n)
Both B _oD at P ₁₀ ) are slid to a larger value by the increase in input voltage, and conversely, the upper and lower limits of the appropriate current are slid to a smaller value in response to a drop in input voltage.

In the above embodiment, the current detection transformer 2 of FIG.
Instead, it is also possible to use an electrical current detection sensor such as a Hall element. Moreover, it is also possible to use a contact relay instead of the SSR in the switching circuit of 8. As an example of the external output display circuit 12, it is also possible to include a 7-segment LED display element and display abnormal circuit numbers in order. As another example, it is also possible to provide individual LED lamps corresponding to neon tube lighting circuits, and to display a circuit determined to be abnormal by lighting the LED lamp corresponding to the abnormal circuit number.

Furthermore, in addition to the input current and input voltage, the phase difference between the two may also be detected, and the presence or absence of an abnormality may be determined from the input power. In other words, due to an abnormality such as a short circuit in the neon tube lighting circuit or a no-load condition, the power factor changes more significantly than changes in the input current. It is larger than in the case of current, making detection easier. Therefore, if the determination is made based on the input power, more accurate abnormality detection becomes possible. In this case too,
As in the case described above, it is advantageous to correct the determination criteria with respect to fluctuations in the power supply voltage.

"Effects of the Invention" The present invention has the following effects due to the above-described configuration.

Regardless of the size of the neon tube lighting circuit, it is an abnormality detection device for one set of load circuits, and it is possible to skillfully use the switching circuit that each lighting circuit is equipped with, without installing a new switching device for each lighting circuit for abnormality detection. By using this method, it becomes possible to detect abnormalities in the entire neon tube lighting circuit with high precision. Therefore, as the scale of the neon tube lighting circuit increases, the economic effect increases in terms of material costs, installation work costs, etc. of the load circuit abnormality detection device. Also,
Since only one set of wiring is required for detecting an abnormality in the neon tube lighting circuit, the system can be made more compact, the amount of wiring can be significantly reduced, and the wiring work can also be significantly shortened.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIG. 2 is a circuit diagram of an embodiment of a switching circuit. FIG. 3 is a flowchart of execution of control by the control circuit 4. (Explanation of symbols of main parts), 1: Power supply, 2: Current detection circuit, 3: Input interface, 4: Control circuit, 5: Microcomputer (CPU), 6:
Memory circuit, 7: Output interface, 8: Switching circuit, 9 ₁ to 9 ₅ : Neon transformer, 10 ₁
~ ₁₀₅ : Neon tube, ₁₁₁ ~ ₁₁₅ : Solid state relay (SSR), 12: External output display circuit,
13: Voltage detection circuit.

Claims (1)

[Claims] 1. In a neon tube lighting circuit consisting of a plurality of neon transformers, a switching circuit is provided between the primary winding of the neon transformer and the power supply and controls the input of power to each neon transformer intermittently. , a current detection means for detecting, on the power supply side, the input current of the neon transformers to which power is sequentially applied one by one by the switching circuit; a voltage detection means for detecting the input voltage on the power supply side; Correspondingly, means for pre-memorizing a range of input current values, and means for reading out the range of input current values and correcting the range of input current values in response to fluctuations in the input voltage detected by the voltage detection means; an abnormality detecting device for a neon tube lighting circuit, comprising abnormality determining means for comparing the detected input current value with the neon tube lighting circuit comprising a neon transformer that is outside the corrected range as abnormal.