JPH06130905A - Status display device - Google Patents

Abstract

PURPOSE:To automatically discover the disconnection of a lamp without the aid of operator's judgment and to specify the position of this lamp by detecting bleeder current and automatically deciding whether the filment of an incandescent lamp is disconnected or not. CONSTITUTION:A circuit for separately passing the bleeder current 7 is prepd. and it is automatically detected by using a controller 18 that the filament of the lamp 16 is not disconnected if the bleeder current 7 flows at all times. Namely, an AC voltage is superposed on the DC power source line of the lamp 16 by using a transformer 33 and the bleeder current 7 is passed to the lamp 16 by this AC voltage. The AC voltage is level converted by a current rectifying and optically coupling element 23 if the lamp 16 is not disconnected. The circuit is so constituted that the position of the disconnected lamp is automatically discovered during the operation of the device body by detecting and judging this level by the controller 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a status display device for displaying various kinds of information in a radar system or the like using an illuminated display device having a filament type incandescent lamp (hereinafter referred to as a lamp) built therein.

[0002]

2. Description of the Related Art FIG. 2 is a diagram showing an internal structure of a conventional status display device. In FIG. 2, 1 is a status display device main body (hereinafter referred to as the device main body), and 2 is a lamp lighting ON.
It is composed of logic levels "H" and "L" for controlling ON / OFF, and the first digital signal 3 among N is a logical sum (O of the digital signal 2 and the lamp test signal).
R) for taking R), 3a is an output terminal of the OR gate 3, 4 is a switching operation by a signal of the OR gate 3, and lamp driving transistors 4a and 4b for turning ON / OFF the current flowing through the lamp are Each of the collector and base electrodes of the transistor 4 is a lamp driving current (IL) flowing when the transistor 4 is ON, and 6 is a lamp illuminating when the conductive transistor 4 is OFF in order to reduce an inrush current flowing when the lamp is lit. A bleeder resistance for flowing a constant current of a certain level to the lamp for preheating, and 7 is a bleeder current (I
B), 8 is an illumination type indicator having a built-in lamp for notifying an operator of a radar device or the like of various status information, 9 is a filament type incandescent lamp or lamp,
Reference numeral 10 is a DC power source for lighting the display, 11 is a digital signal for controlling the Nth display, 12 is an OR gate, and 12a is O.
The output terminal of the R gate 12, 13 is the same lamp driving transistor as the transistor-4, 13a and 13b are collector and base electrodes of the transistor 13, 14 is a bleeder resistance, and 15 is the Nth illumination type among N An indicator, 16 is an Nth lamp, 17 is a digital signal for lamp test, 18 is a microcomputer for exchanging display data with an external device (not shown) and logically controlling the display data. Controller, 19
Is a signal line for interfacing with an external device. The conventional status display device is configured as described above. Now, considering the initial state immediately after the power of the device body 1 is turned on, the logic levels of the digital signals 2 and 11 and the lamp test signal 17 are "L". , Therefore
Since the logic levels of the output terminals 3a and 12a of the OR gates 3 and 12 are also "L", the transistors 4 and 13 are turned off.
It is in a state. At this time, a bleeder current 7 flows from the DC power source 10 through the lamp 9 and the bleeder resistance 6, and similarly, a bleeder current also flows through the lamp 16 and the bleeder resistance 14 to the Nth line to preheat the lamp 9 to the lamp 16. . Due to this preheating, the resistance of the filament in the lamp is increased more than when there is no current in the lamp. Next, when the apparatus body 1 enters the operating state, the controller 1 built in based on the display data transmitted and received from the external device (not shown) through the signal line 19.
By the control of 8, the logic level of the digital signal 2 becomes "
When L "changes to" H ", the logic level of the output terminal 3a of the OR gate also becomes" H ", and the output terminal 3 of the OR gate 3
A current flows from a to the base terminal 4b of the transistor 4, and the transistor 4 is turned on. As a result, the lamp driving current 5 flows from the DC power supply 10 through the lamp 9 into the collector terminal 4a of the transistor 4, and the operator of the apparatus body 1 is notified of the status information of the display name printed or engraved on the surface of the display 8. It When the logic level of the digital signal 11 becomes "H" under the control of the controller 18, the OR operation is performed by the same operation as above.
Gate 12a to base terminal 13 of transistor 13
The base current is supplied to b, the lamp drive current is supplied from the DC power supply 10 to the lamp 16 and the collector terminal 13a of the transistor 13, the lamp 16 is turned on, and the status display name of the Nth display 15 is known to the operator. To be done. Next, a lamp test is performed when the lamp does not light up even if a regular operation is performed. Normally, a switch (not shown) for the lamp test is provided on the operation panel surface of the apparatus body 1. While the operator is pushing, the lamp test signal 17 becomes "H" level, and then the output terminals 3a to 1 of the OR gate 1 regardless of the logic levels of the N lines of the digital signals 2 to 11.
The output levels up to 2a are all "H". As a result, all the transistors 4 to 13 should be in the ON state, and all the lamps from the lamp 9 to the lamp 16 should be turned on. Therefore, regarding the lamps that the operator judged to be strange and did not turn on, Remove the lamp from the display, check the continuity of the lamp itself, and then replace the lamp. When the lamp test switch is released, the logical level of the lamp test signal 17 returns to "L", and therefore the lamp 9 to the lamp 16 return to their original states. In this way, the lamp test is carried out.

[0003]

The conventional status display device as described above has the following problems. That is, when many lamps are turned on at one time, no matter how the lamp is preheated by the bleeder resistance, a large current suddenly flows into the power line of the display to turn on the lamps, causing power noise, As a result, other signal circuits with low signal levels will be affected by malfunctions, and a DC power supply with a large output power must be equipped to supply a large current, and it is predicted when a lamp burnout will occur. Since the lamp did not come on, the operator felt that the lamp display was abnormal, and the operator had to suspend the operation of the main body of the apparatus in order to perform a lamp test and determine the abnormality of the lamp. The present invention has been made to solve such a problem, and detects the disconnection of the lamp automatically without applying a large current to the lamp and without the operator's judgment, and determines the position of the lamp. The purpose is to inform the operator.

[0004]

In a status display device according to the present invention, a circuit for separately supplying a bleeder current is prepared, and if the bleeder current is constantly flowing, it is confirmed that the filament of the lamp is not broken. That is, it was automatically detected using.

[0005]

According to the present invention, an AC voltage is superimposed on the DC power supply line of the lamp by using a transformer, and a bleeder current is caused to flow through the lamp by the AC voltage, and if the lamp is not broken, the AC voltage is rectified. The circuit is configured to detect the position of the lamp that is automatically disconnected during the operation of the main body of the device by converting the level by the optical coupling element and detecting and judging the level by the controller.

[0006]

1 is a diagram showing the internal structure of a status display device according to an embodiment of the present invention, in which 1 is a status display device main body and 2 is the first of N display control devices. Digital signal, 3 is a buffer, 3a is an output terminal of the buffer, 4 is a lamp driving transistor,
4a and 4b are collector and base electrodes of the transistor 4, 5 is a lamp driving current (IL), 7 is a bleeder current (IB), 8 is a first illuminated display, 9 is a lamp, and 10 is a lamp display. Direct current power source, 11 is an Nth digital signal for controlling the display, 12 is a buffer, 12
a is an output terminal of the buffer, 13 is a transistor for driving the lamp, 13a and 13b are collector and base electrodes of the transistor 13, 15 is an Nth illuminated display, 16 is a lamp, 18 is a controller, 19 is a signal The line, 20 is a diode for rectifying the AC voltage,
Reference numeral 21 is a capacitor for smoothing the half-wave DC voltage rectified by the diode 20, 22 is a current limiting resistor, 23 is an optical coupling element for separating the ground line and performing level conversion, and 24 is a switching operation. Load resistance, 2
5 is a digital signal for identifying whether or not the lamp 9 is broken, 26 is a rectifying diode, 27 is a smoothing capacitor, 28 is a current limiting resistor, 29 is an optical coupling element, 30 is a load resistor, Reference numeral 31 is a digital signal for identifying whether or not the lamp 16 is broken, 32 is a diode for preventing reverse voltage, 33 is a transformer for superimposing an AC voltage, 34 is an AC power supply whose output voltage can be varied. Three
5 is a logic power supply voltage. In the status display device configured as described above, considering the initial state immediately after the power of the device body 1 is turned on, the logic level of the digital signal 2.11 is “L”, and therefore the buffer 3. Since the logic levels of the output terminals 3a and 12a of 12 are also "L", the transistors 4 to 13 are turned off.
It is in a state. At the same time when the power is turned on, the AC power supply 34 generates an AC voltage having a certain frequency, and the AC voltage also appears on the secondary side of the transformer 33. Considering a half cycle in which the diode 20 is forward biased in one cycle of alternating current,
If the lamp 9 to the lamp 16 are not broken, an AC voltage on the secondary side of the transformer 33 causes a sinusoidal half-wave pulse current to flow through the lamp 9, the diode 20 and the smoothing capacitor 21, and this current preheats the lamp 9. At the same time, the smoothing capacitor 21 is charged to a certain voltage level. At the same time, a current flows through the lamp 16, the diode 26, and the smoothing capacitor 27 by the transformer 33, the lamp 16 is also preheated, and the smoothing capacitor 27 is charged with a certain level of voltage. The value of the bleeder current sets the output voltage of the AC power supply 34 to an appropriate value. Next, when the diode 20 enters a half cycle in which it is reverse biased, the diodes 20 to 26 are reverse biased,
No current flows from the lamp 9 to the lamp 16, so that the electric charge charged in the smoothing capacitor 21 is changed to the current limiting resistor 22.
A current is discharged through the light emitting diode on the input side of the optocoupler 23, and as a result, a current substantially determined by the logic power supply voltage 35 and the load resistor 24 flows to the collector of the transistor forming the output stage of the optocoupler 23. Then, when the transistor is turned on, almost O
The digital signal 25 of V, that is, the logic level "L" is output. Similarly, the electric charge charged in the smoothing capacitor 27 also flows as a current through the current limiting resistor 28 and the input side light emitting diode of the optical coupling element 29, and the optical coupling element 29.
By the operation of the switching circuit composed of the transistor and the load resistor 30 that form the output stage of the
The digital signal 31 is output. After that, the smoothing capacitors 21 to 27 are repeatedly charged and discharged by successive AC cycles, but the frequency of the AC power source 34 and the smoothing capacitor 21 are changed so that a constant current flows to the light emitting diode on the input side of the optical coupling elements 23 to 29. Since the capacitance of 27 is selected, the logic levels of the digital signals 25 to 31 are kept at "L". Next, if the lamp 9 is broken, the bleeder current does not flow, so the smoothing capacitor 21 is not charged, and therefore the optical coupling element 22 is not charged.
Since no current flows through the input side light emitting diode of, the logic power supply voltage 35 is output as it is as the logic level "H" to the collector of the transistor at the output stage of the optical coupling element 23. Since the digital signals 25 to 31 are read by the controller 18 as status data, it is judged in the controller 18 that the logical level "L" is normal and "H" is broken, and as a result, the broken lamp is detected. The position is displayed on an abnormality display panel (not shown) of the apparatus body 1 and the operator is informed. The same operation is performed for lamps other than the lamp 9. Next, when the apparatus main body 1 enters the operating state, the logic level of the digital signal 2 changes from "L" to "L" by the control of the built-in controller 18 based on the display data transmitted and received from the external device through the signal line 19. When it goes to H ”, buffer 3
Also, the logic level of the output terminal 3a of "1" becomes "H", current flows from the output terminal 3a of the buffer-3 to the base terminal 4b of the transistor-4, and the transistor 4 is turned on. As a result, the lamp driving current 5 flows from the DC power supply 10 through the diode 32 and the lamp 9 into the collector terminal 4a of the transistor 4, and the status information of the display name printed or engraved on the surface of the display 8 is displayed by the operator of the apparatus body 1. Be informed. At this time, the voltage level of the collector terminal 4a becomes a saturation voltage close to 0V due to the ON operation of the transistor 4, but the lamp driving current 5
A current obtained by adding a bleeder current 7 to the current flows. In addition, the logic level of the digital signal 11 is the controller 18
When it becomes "H" by the control of the above, the base current from the buffer 12a to the base terminal 13b of the transistor 13 and the diode 3 from the DC power source 10 by the same operation as above.
2, a lamp drive current flows through the lamp 16 and the collector terminal 13a of the transistor 13, respectively, and the lamp 16 is turned on to notify the operator of the status display name of the Nth display unit 15. The diode 32 is inserted so that an abnormal voltage is not applied to the DC power supply 10 side.

[0007]

As described above, according to the present invention, by detecting whether or not a bleeder current is flowing,
A large number of bleeder resistances can be reduced, and since a large current does not flow, there is no fear of malfunction due to power supply noise, and the wires are quickly disconnected without the trouble of searching for the disconnected lamp among the many lamps. The effect is that the position of the lamp can be specified.

[Brief description of drawings]

FIG. 1 is an internal configuration diagram showing an embodiment of a status display device of the present invention.

FIG. 2 is an internal configuration diagram showing a conventional status display device.

[Explanation of symbols]

 20 Rectifier Diode 21 Smoothing Capacitor 22 Current Limiting Resistor 23 Optical Coupling Element 26 Rectifying Diode 27 Smoothing Capacitor 28 Current Limiting Resistor 29 Optical Coupling Element 33 Transformer

Claims (1)

[Claims] 1. An N-type illuminated display for incorporating various filament status incandescent lamps for displaying various status information, and an AC voltage on a DC power supply line for reducing inrush current when the incandescent lamp is lit. For superimposing a bleeder current, an AC coupling circuit for rectifying AC voltage and converting the level, and outputting a status signal indicating whether or not the bleeder current is flowing, external equipment and display data It consists of a controller that performs signal transmission / reception and the above-mentioned logic control for lighting the indicator, and sends a bleeder current for preheating to the incandescent bulb, and detects whether the filament of the incandescent bulb is broken by detecting the bleeder current. A status display device characterized in that it is configured to automatically determine whether or not to notify the operator.