JPS6237897A - Abnormality detector for neon tube lighting circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for detecting circuit abnormalities in neon tubes, neon transformers, etc. of neon tube lighting circuits.

(Prior Art) In general, neon tube lighting circuits are used to detect circuit abnormalities in neon tubes, neon transformers, etc.
As seen in Publication No. 55 and Publication No. 16074 of 1983, each neon transformer is equipped with one set of load abnormality detection devices, such as an overcurrent detection device or an undervoltage detection device, Anomalies in the load circuit were detected.

(Problems to be Solved by the Invention) Recent neon tube lighting circuits tend to become larger in size as information technology progresses. As a result, neon tube lighting circuits have become more complex, and the need for load circuit abnormality detection devices has increased. Against this background, it is difficult to equip each neon transformer with one set of load circuit abnormality detection devices as in the past, as the cost of materials and construction increases as the scale of neon tube lighting circuits expands. This would be 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, and a means for individually opening and closing the circuits connected to the power supply of the neon transformer to connect each neon transformer from the power supply. means for detecting the input current flowing into the transformer at the power supply handle; a storage means for pre-memorizing the range of input current values corresponding to each neon transformer; A means is provided for comparing the input current value and determining that a neon tube lighting circuit comprising a neon transformer outside the range is abnormal.

(Embodiment) FIG. 1 is a circuit configuration diagram of an embodiment of the present invention consisting of five neon tube lighting circuits. 10. -10 are neon tubes, the electrodes of which are connected to neon transformers 91-9. are connected to the secondary output terminals of each. Neon transformer9. ~95
All primary input terminals of are connected to power supply 1. Reference numeral 2 denotes a current detection transformer that detects current from the output section of the power supply 1 and converts it into an electric 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 B+a''Bst+ of the primary input current of an appropriate neon transformer when a normal neon tube is lit. Lower limit value B+n-
Bsn is memorized. A digital signal output from the control circuit 4 is sent to the output interface 7 and converted into an electrical signal, one of which is sent to the external output display circuit 12,
The other one is sent to the switching circuit 8. Inside the switching circuit 8, as shown in FIG. 2, solid state relays (hereinafter referred to as SSR) 111 to 115 are installed.
load contact terminals are connected in series to one side of the primary input power supply lines of the neon transformers 91-95. The electrical signal line of 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 9I to 9. oN, oF of the next input power supply to
Controls F.

Now, the operation will be explained next. A flowchart for executing control of the control circuit 4 is shown in FIG.

Note that P and PI6 in the figure indicate each step of the flowchart.

The circuit number n is set to O in P2. At P3, add 1 to n to set n to 1. Neon tube 10 from control circuit 4 at P4.
A digital signal for lighting is output to the output interface 7. The digital signal input to the output interface 7 is converted into an electrical signal and sent to the switching circuit 8.
is output to.

In the switching circuit 8, the load contact terminal of only 5SR11+ is turned ON by the electrical signal from the output interface 7, and the neon transformer 9. only connected to power,
Neon tube 10. only lights up. The input current at that time is detected by the current detection circuit 2, converted into a digital signal by the input interface 3, and the control circuit 4 reads the input current value A when only the neon tube 10I is lit at P. P
At step 6, the microcomputer 5 reads the appropriate current upper limit value B111 from the memory circuit 6, and at step P7 compares it with the measured input current value AI. When the input current value AI is larger than the appropriate current upper limit value BID, it is determined that the circuit is abnormal in P8, and the abnormal circuit number n=l is sent to the storage circuit 6 and stored.

At other times, the microcomputer 5 reads the appropriate current lower limit value BID from the memory circuit 6 at P, and then returns to P. A comparison is made with the input current value A1. When the input current value A is smaller than the appropriate current lower limit value B1D, it is determined that the circuit is abnormal at P, and the abnormal circuit number n=1 is sent to the storage circuit and stored.

At other times, neon tubes 10. A circuit that lights up is judged to be normal. Next, since n in pus is smaller than 5, which is the number of neon tube lighting circuits in this example,
Returning to P3, the steps P3 to pus described above are repeated four times in this embodiment. Thereafter, the microcomputer 5 reads out the abnormal circuit number in the memory circuit 6 using the PI 6 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 the embodiment described above, it is also possible to use an electrical current detection sensor such as a Hall element in place of the current detection transformer 2 shown in FIG. Also, S in the switching circuit of 8
It is also possible to use a contact relay instead of the SR. 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. In addition, as another example, it is equipped with individual LED lamps compatible with neon tube lighting circuits,
It is also possible to display a circuit determined to be abnormal by lighting an LED lamp corresponding to the abnormal circuit number. Furthermore, in addition to detecting the input current, the input voltage is also detected, and a more accurate abnormality detection device can be constructed by correcting the increase or decrease in the input current due to fluctuations in the power supply voltage against the abnormality judgment criteria. can. For example, in response to an increase in power supply voltage, both the upper and lower limits of appropriate current in the above embodiment are slid to larger values by the increase in power supply voltage, and conversely, in response to a decrease in power supply voltage, the appropriate upper and lower limits of current are decreased. It may be made to slide to a value.

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, also
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.

Irrespective of the scale of the neon tube lighting circuit, it becomes possible to detect an abnormality in the entire neon tube lighting circuit with the -set load circuit abnormality detection device. Therefore, the larger the scale of the neon tube lighting circuit, the greater the economic effect will be in terms of material costs, installation work costs, etc. for the load circuit abnormality detection device. Since only one set of wiring is required for the system, the system can be made smaller, 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 configuration diagram of an embodiment of the present invention, and FIG. 2 is a circuit diagram of an embodiment of the present invention.
FIG. 2 is a circuit diagram of an embodiment of a switching circuit. FIG. 3 is a flowchart of the execution of control by the control circuit 4. (Explanation of symbols of main parts) 1: Power supply 2: Current detection circuit 3: Input interface 48 Control circuit 5: Microcomputer (CPU) 6: Memory circuit 7: Output interface 8 Niswitching circuit 9, - 9. : Neon Transformer 10+ ~10. : Neon tubes 111 to 115 : Solid state relay (SS
R) 12: External output display circuit

Claims (1)

[Claims] 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 on/off the input of power supply to each neon transformer, and the switching circuit 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; a storage means for storing in advance a range of input current values corresponding to each neon transformer; A neon tube lighting circuit comprising abnormality determining means for reading a range of an input current value, comparing it with the input current value detected by a current detection means, and determining that a neon tube lighting circuit comprising a neon transformer outside the range is abnormal. Anomaly detection device.