JP2002280190A - Led, signal lamp using bulb, and disconnection detecting device for illuminating lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disconnection detecting device capable of automatically detecting the disconnection of a signal lamp and an illuminating lamp using a LED and a bulb lighted by a commercial power supply as a pulse signal. SOLUTION: A bulb disconnection detecting device for a double filament bulb is equipped with a voltage detecting circuit 82 to detect an AC voltage applied to the double filament bulb 84 having two independent filaments, a bulb current detecting circuits 83-1, 83-2 to detect current flowing in respective filaments, and a disconnection determining circuit 85 to input the output of the voltage detecting circuit and the bulb current detecting circuit. It the filament 84-1 of the bulb is disconnected with the AC voltage applied, the output of the bulb current detecting circuit 83-1 gets to 'H' level from a pulse signal, the output of a re-trigger.single.shot (with CR) 88 gets to 'H' level from 'L' level, and the output of the voltage detecting circuit 82 forming one more input of a 2-input AND 89 is generating a pulse signal, and therefore, the output of the disconnection determining circuit 85 continuously generates a pulse signal and the disconnection of the bulb can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disconnection detecting device which can automatically detect a disconnection of a signal lamp and an illuminating lamp using a LED and a bulb which are turned on by an AC power supply as a pulse signal.

[0002]

2. Description of the Related Art Generally, a disconnection detecting device for an LED lamp and a bulb lamp uses a current transformer (C
T), detected as a very small voltage, and after rectification, AD
A current detection circuit that converts to a digital signal with a converter, and a voltage detector that detects the voltage applied from an AC power supply as a minute voltage with a voltage transformer (PT), rectifies it, and then converts it to a digital signal with an AD converter This is a circuit and a method in which the CPU determines the two digital signals to determine the disconnection of the LED lamp and the bulb lamp.

[0003]

However, the above-described disconnection detecting devices for LED lamps and bulb lamps have the following problems. The first problem is that the instability of the voltage applied from the AC power supply may hinder accurate detection of disconnection of the LED lamp and the bulb lamp. The second problem is that
Since it is composed of the CT of the current detection circuit, the PT of the voltage detection circuit, the CPU, and the like, the device is large and the cost is high. It is an object to solve the above problems.

[0004]

According to a first aspect of the present invention, there is provided a device for detecting disconnection of an LED lamp, wherein one or a plurality of LED units are provided in a state where an AC voltage is applied. Is provided with a means for outputting a pulse signal to the outside in the case of disconnection.

According to a second aspect of the present invention, a voltage detection circuit is connected in parallel with a power supply line between a power supply switch for applying an AC voltage and a rectifier bridge or a rectifier diode, and drives a photocoupler only with an AC half-wave. And a means for outputting a pulse signal as an output of the voltage detection circuit when an AC voltage is applied.

According to a third aspect of the present invention, there is provided a current detecting circuit, to which a voltage having a full-wave rectified or half-wave rectified waveform is applied.
A photocoupler connected in series to the LED unit for detecting the current flowing through the ED unit is provided. When the voltage of the full-wave rectification or the half-wave rectification waveform is applied and the current is flowing through the LED unit, the current detection is performed. Means for outputting a pulse signal as an output of the circuit is provided.

In accordance with a fourth aspect of the present invention, there is provided a disconnection determination circuit which receives the output of each of a voltage detection circuit and one or a plurality of current detection circuits as inputs and applies a voltage of a full-wave rectification or a half-wave rectification waveform to the LED unit. A means is provided for continuously outputting a pulse signal as an output of the disconnection determination circuit when the voltage is applied and one or more LED units are disconnected.

According to a fifth aspect of the present invention, there is provided a simplified LED lamp disconnection detecting device including a voltage detecting circuit, a rectifying bridge, a simple LED current detecting circuit, a current limiting resistor, an LED group, and a disconnection determining circuit. And a means for outputting a pulse signal continuously to the output when the LED lamp is disconnected. A simple LED current detection circuit according to claim 5 has a function of connecting a transistor in series to an LED lamp, and including a bias resistor and a photocoupler in parallel between a collector and a base of the transistor, and detecting a current flowing through the LED lamp. Have.

According to a sixth aspect of the present invention, there is provided an apparatus for detecting a disconnection of a bulb lamp, comprising a voltage detection circuit, a current detection circuit for the bulb lamp, and a disconnection determination circuit.
Means is provided for outputting a pulse signal when the bulb lamp is disconnected. The voltage detection circuit is a circuit similar to the second aspect. The lamp lamp current detection circuit is connected in series to the lamp lamp, and a rectifying diode that flows a negative half wave of an alternating current flowing through the lamp lamp to which an AC voltage is applied and a transistor that flows a positive half wave are arranged in parallel. A bias resistor and a photocoupler are connected in parallel between the collector and the base of the transistor, and a means for generating a pulse signal at the output when an AC voltage is applied and the bulb lamp is disconnected is provided. The disconnection detection circuit is a circuit similar to the fourth embodiment.

According to a seventh aspect of the present invention, there is provided a disconnection detecting apparatus for a double filament lamp, comprising: a voltage detecting circuit; A disconnection determination circuit that receives the outputs of the detection circuit and the two current detection circuits as inputs, and a pulse signal is output continuously from the disconnection determination circuit when the AC voltage is applied and one or two filaments are disconnected. Is provided.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing a basic configuration example of a disconnection detection device for an LED lamp including a plurality of LED units, and FIG. 2 is a waveform of each part A to H in FIG.

That is, as shown in FIG. 1, an LED lamp disconnection detecting apparatus according to the present embodiment comprises an AC power supply 1
Power switch 2 for applying AC power supply 1 to lamp 15
A voltage detection circuit 3 connected in parallel to the power switch 2 to detect a voltage; a rectification bridge 14 connected next to the voltage detection circuit 3; and a plurality of LED groups 16-1 connected to the output of the rectification bridge 14. ~ 16-N and its driving unit,
In addition, the current detection circuits 17-1 to 17-N for detecting the respective currents of the LED group, and the outputs of the voltage detection circuit 3 and the current detection circuits 17-1 to 17-N are input to the LED lamp 15 A disconnection determination circuit 36 for determining disconnection is provided.

The voltage detecting circuit 3 shown in FIG. 1 has a photocoupler driving circuit and a photocoupler 12 connected in series. The photocoupler driving circuit switches the transistor 6 from a voltage close to zero at the time of rising of the positive half-wave voltage of the AC waveform via the rectifier diode 4 and the transistor 6.
When turned on, a current flows through the LED of the photocoupler 12 to light it, and the current of the LED of the photocoupler 12 is cut off at a voltage close to zero when the same half-wave falls. As a result, when an AC voltage is applied to the voltage detection circuit 3, the output of the photocoupler 12 has substantially zero voltage in the positive half-wave.
L ”level (accurately, the collector-emitter voltage),
In the case of a negative half-wave, the power supply voltage becomes almost “H” level of the DC power supply, and becomes a pulse signal. Note that the output of the voltage detection circuit 3 continuously generates a stable pulse signal when the voltage of the AC power supply is 10 V or more with respect to the fluctuation of the power supply voltage, and is extremely stable. On the other hand, when no AC voltage is applied to the voltage detection circuit 3, no current flows to the photocoupler 12, and the output of the photocoupler 12 is continuously maintained at the “H” level.

The current detection circuit 17-1 shown in FIG. 1 comprises a drive circuit for driving the LED group 16-1 and a photocoupler 26 for detecting a current. The driving circuit includes transistors 19, 21, 23, a diode 22, a resistor 20,
24 and 25. AC power supply 1 is switch 2
The operation of the drive circuit when applied to the LED lamp 15 through the LED is performed at a specific voltage of a rising portion of the AC half-wave voltage determined by the number of LEDs of the LED group and the forward voltage characteristic with respect to the full-wave rectified waveform. The transistor 19 is turned on, and its current increases as the voltage increases. Then, the transistors 23 and 21 are turned on by the voltage between both ends of the resistor 25.
Although the transistor 6 is normally turned off, by setting the value of the resistor 9 to several hundreds Ω or less, the transistor 6 stays in an appropriate active region, not in a cut-off region where it is completely turned off. Current flows in In the falling part of the voltage of the same AC half-wave, the current of the LED group 16-1 is O at the specific voltage determined by the LED group 16-1.
It becomes FF. As a result, the current flowing through the LED group 16-1 has a waveform like the second zone in FIG. 2-C.

The LEDs of the photocoupler 26 connected in series to the LED group 16-1 in FIG.
The same current flows as the current flowing through Therefore, the output of the photocoupler 26 is LE as shown in the second zone in FIG.
At substantially the same timing as the current flowing through the D group 16-1 "
The pulse signal becomes L level.
When a disconnection occurs in 6-1, the LE of the photocoupler 26 is
D does not flow, and the output of the photocoupler 26 is as shown in FIG.
It changes to "H" level like the third zone of -D,
The H level is continuously maintained.
Similarly, when the AC power supply 1 is not applied to the lamp 15, the output of the photocoupler becomes “H” level as in the first zone in FIG.

The voltage detection circuit 3 and the current detection circuit 1
On the output side of each photocoupler 7-1, pull-up resistors 13 and 27 are connected to appropriately drive the photocoupler 12 and the photocoupler 26, thereby guaranteeing the “H” level. . Also, the current detection circuit 1
7-2 to 17-N are circuits similar to the current detection circuit 17-1.

The disconnection determination unit 33-1 receives the output of the voltage detection circuit 3 and the output of the current detection circuit 17-1 as inputs, and outputs a Schmitt trigger inverter 28, a retrigger
It comprises a single shot circuit 31, a two-input AND 32. The disconnection determination unit 33-1 first outputs the output signal of the current detection circuit 17-1 to a Schmitt trigger
It is input to the inverter 28 and its output is connected to the input of the retrigger single shot circuit 31. The output of the retrigger single shot circuit 31 is connected to one input of a two-input AND 32. Further, the output signal of the voltage detection circuit 3 is connected to one input of the two-input AND 32. As a result, the disconnection determination unit 33
The output of -1 is the output of the two-input AND32 and LE
11 shows an output signal indicating disconnection determination of D group 16-1.

Retrigger single shot circuit 31
Is such that when the input level changes from "H" level to "L" level, the output changes for a preset time, and the output is changing, that is, within the time-up time. When the input level changes from "H" level to "L" again, the output level continuously changes for a set time from that point. In this example, it is assumed that the set time of the retrigger single shot circuit is set to, for example, 0.75 times the period T of the sine wave AC of the AC power supply by selecting the resistor 29 and the capacitor 30.

The disconnection determination circuit 36 has a multi-input OR 34 which receives the outputs of the N disconnection determination units 33-1 to 3N.
And a Schmitt trigger inverter 35 having the output as an input. Next, regarding the circuit operation of the disconnection determination circuit 36 of the LED lamp according to the present invention having the above configuration,
The waveform diagram of FIG. 2 will be described by dividing it into three zones at the timing of the time axis. In the first zone, the power switch 2 is set to “O”
In the second zone, AC power is applied to the rectifying bridge 14 when the power switch 2 is "ON", and all the LED units 18-1 are in the second zone. To N. That is, all the LED groups are in a normal state without disconnection, and the third zone has one LED group 1 in the second state.
Only 6-1 is disconnected, and no current flows through the LED group 16-1.

First, in the first zone, the waveforms of the outputs B and D of the photocoupler both maintain the “H” level,
The waveforms of the outputs E, F, and G maintain the “H” level, and the output H of the disconnection determination circuit 36 maintains “L”.

In the second zone, the photocoupler 12
The current B flows into the LED of the photocoupler 12 as a positive half-wave of the sine wave A by the rectifier diode 4 and becomes a pulse signal at a timing corresponding to the current. At this time,
As described above, since the current flows through the LED of the photocoupler 26 at a voltage equal to or higher than a certain voltage of the full-wave rectified waveform, the waveform D becomes a pulse signal at a timing corresponding thereto. In addition, the retrigger system Connected to the retrigger single-shot circuit 31 via the trigger inverter 28, and the set time period T /
Since it is longer than 2, the level becomes “L” level, and that state is maintained. Therefore, the output F of the two-input AND 32 is also "
L "level. In addition, the disconnection determination unit 33-2 ~
The output G of N is similar to the waveform of F. As a result, the output G of the disconnection determination circuit 36 becomes "H" level, and the state is maintained.

In the third zone, the photocoupler 12
Is a pulse signal as in the second zone,
When the disconnection of the LED group 16-1 occurs, the photocoupler 2
The output D of No. 6 becomes "H" level. Therefore, retrigger single Therefore, the output F of the two-input AND 32 has substantially the same waveform as the B pulse signal after the set time of the retrigger single shot circuit. Outputs G of the other disconnection determination units 33-2 to 33-N are output from the LED groups 16-2 to 16-N.
Are all in the "L" level because they are in a normal state. Next, the disconnection determination units 33-1 to 33-N
The output of the multi-input OR 34 having all of the outputs as inputs is a pulse signal similar to the output F of the disconnection determination unit 33-1. As a result, the output G of the disconnection determination circuit 36 becomes a pulse signal obtained by inverting the output of the disconnection determination unit 33-1.
As a result, the disconnection determination circuit 36 sets the LED group 16-
1 can be detected.

Further, even if two or more or all of the LED groups 16-1 to 16-N are disconnected,
Since the output of the disconnection determination unit corresponding to the group is a pulse signal similar to the output of the voltage detection circuit 3, the output H of the disconnection determination circuit 36 is a pulse signal. Therefore, the disconnection determination circuit 36 generates a pulse signal in response to the occurrence of one or more or all disconnections of the LED group, and can detect the disconnection of the LED group.

FIG. 3 is a circuit diagram showing a basic configuration example of a disconnection detecting device for a simple LED lamp.

As shown in FIG. 3, an apparatus for detecting disconnection of a simple LED lamp according to this embodiment comprises an AC power supply 37, a power switch 3
8, voltage detection circuit 39, rectifier bridge 40, simple LED
Current detection circuit 41, LED group 42, current limiting resistor 4
3. A disconnection determination circuit 44 is provided. Simple LED light 5
2 applies an AC power supply 37 to a rectifier bridge 40 by a power switch 38 and performs full-wave rectification, and then, through a transistor 45 for detecting current and a current limiting resistor 43, LE
The voltage is applied to the D group 42 to light up.

3 includes a rectifier diode 46, a photocoupler driving circuit 47, and a photocoupler 48.
And has the same function as the voltage detection circuit of FIG. As a result, when an AC voltage is applied, the output of the voltage detection circuit 39 is substantially equal to the “L” level (correctly, the saturated collector-emitter voltage) at which the voltage is substantially zero in the positive half-wave, and substantially zero in the negative half-wave. The power supply voltage of the DC power supply becomes “H” level and becomes a pulse signal. On the other hand, when the power switch 38 is off,
That is, when no AC voltage is applied to the voltage detection circuit 39, no current flows through the LED of the photocoupler 48,
The output of the voltage detection circuit 39 keeps the state of “H” level continuously.

The simple LED current detection circuit 41 shown in FIG.
A bias resistor 49 is connected between the collector and the base of the transistor 45, and a photocoupler 50 in which a resistor 51 for adjusting a current flowing through the LED of the photocoupler 50 is connected in series. The base current flowing between the collector and the base of the transistor 45 is diverted to the LED of the photocoupler 50 connected in parallel to the bias resistor 49 to drive the photocoupler 50. The output of the simple LED current detection circuit 41 is the output of the photocoupler 50. The output will be described in three states. The first state is a state where the power switch 38 is off, that is, the simple LED lighting device 52.
Is not applied, the output of the simple LED current detection circuit 41 becomes "H" level. The second state is when the power switch 38 is on and the simple LED lamp 52 is normally lit, and when the full-wave rectified voltage is applied to the LED group 42, the number of LEDs and the forward voltage A current flows through the LED group 42 at a voltage higher than the voltage determined by the characteristics, and no current flows through the LED group 42 at a voltage lower than this voltage.
The output of the ED current detection circuit 41 is a pulse signal. The third state is a case where the simple LED lamp 52 is disconnected in the second state.
The output of the current detection circuit 41 for D becomes "H" level.

The disconnection determination circuit 44 shown in FIG. 3 has a configuration in which a Schmitt trigger inverter 35 is connected in series to the output of the disconnection determination unit 33 shown in FIG. 1, and operates similarly to the circuit shown in FIG. The output of the disconnection determination circuit 44 in the first state is
Since both the output of the voltage detection circuit 39 and the output of the simple LED current detection circuit 41 become “H” level, they continuously become “L” level. The output of the disconnection determination circuit 44 in the second state is
Since both the output of the voltage detection circuit 39 and the output of the simple LED current detection circuit 41 are pulse signals, they continuously go to the “H” level. The output of the disconnection determination circuit 44 in the third state is a pulse signal because the output of the voltage detection circuit 39 is a pulse signal and the output of the simple LED current detection circuit 41 is at the “H” level. As a result, disconnection detection of the simple LED lamp 52 becomes possible because the output of the disconnection determination circuit 44 becomes a pulse signal. In addition, disconnection detection of a simple LED lamp in which a plurality of LED groups are connected in parallel includes a voltage detection circuit,
As in the case of FIG. 1, this can be achieved by providing a simple LED current detection circuit and a disconnection determination circuit by the number of LED groups.

FIG. 4 is a circuit diagram showing a basic configuration example of a disconnection detecting device for a light bulb having one filament.

That is, as shown in FIG. 4, the bulb disconnection detecting apparatus of this embodiment is connected in parallel to the bulb 58, a power switch 60 for applying an AC power supply 59 to the bulb 58, and the bulb 58. Voltage detection circuit 61 for detecting voltage
And a current detection circuit 62 for a light bulb connected in series to the light bulb 58 to detect a current, and a disconnection determination circuit 63 for determining the disconnection of the light bulb 58 using the respective outputs of the voltage detection circuit 61 and the current detection circuit 62 for the light bulb as inputs. It is composed of

4 includes a rectifier diode 64, a photocoupler driving circuit 65, and a photocoupler 6.
6 and has the same function as the voltage detection circuit of FIG. As a result, when the AC voltage is applied, the output of the voltage detection circuit 61 has a voltage substantially zero in a positive half-wave.
L ”level (accurately, the collector-emitter voltage),
In the case of a negative half-wave, the pulse signal becomes almost the power supply voltage “H” level of the DC power supply. On the other hand, when the power switch 60 is off, that is, when no AC voltage is applied to the voltage detection circuit 61, no current flows through the LED of the photocoupler 66, and the output of the voltage detection circuit 61 is at the “H” level. Is continuously maintained.

The current detection circuit 62 for a light bulb shown in FIG. 4 has a rectifier diode 67 and a transistor 68 connected in opposite directions. A bias resistor 69 is connected between the collector and base of the transistor 68, and a resistor 72 for limiting the current. Are connected in series to a photocoupler 71.
The Zener diode 70 shown in the figure is a protection element for reducing the influence of the inrush current of the light bulb on the LED of the photocoupler 71. The positive half-wave current flowing through the bulb 58 flows through the transistor 68, and the negative half-wave current flows through the rectifier diode 6.
Flow through 7. The base current flowing between the collector and the base of the transistor 68 is diverted to the LED of the photocoupler 71 connected in parallel to the bias resistor 69 to drive the photocoupler 71. The output of the bulb current detection circuit 62 is
This is the output of the photocoupler 71. The output will be described in three states. The first state is a state in which the power switch 60 is off, that is, when no current is applied to the bulb 58, and the output of the bulb current detection circuit 62 becomes "H" level. The second state is that the power switch 60 is on and the light bulb 58
Is normally lit, the AC voltage is applied to the light bulb 58 to cause a current to flow, and when a positive half-wave current flows to the light bulb 58, the output of the photocoupler 71 becomes the “L” level. . However, even when a current flows through the light bulb 58, no current flows through the transistor 68 in the negative half-wave, and the output of the photocoupler 71 becomes "H" level. As a result, when a current flows through the bulb 58, the output of the bulb current detection circuit 62 becomes a pulse signal. The third state is when the light bulb 58 is disconnected in the second state. No current flows through the transistor 68, and the output of the light bulb current detection circuit 62 becomes “H” level.

The outputs of the photocouplers of the voltage detection circuit 61 and the bulb current detection circuit 62 are connected to a DC power supply 7.
4. Pull-up resistor 7 to which DC voltage VCC is applied
5, 73 are connected, thereby guaranteeing the "H" level.

The disconnection determination circuit 63 of FIG. 4 has a configuration in which the Schmitt trigger inverter 35 is directly connected to the output of the disconnection determination unit 33 of FIG. 1, and operates in the same manner as the circuit of FIG. The output of the disconnection determination circuit 63 in the first state is
Since both the output of the voltage detection circuit 61 and the output of the electric current detection circuit for a light bulb 62 are at the “H” level, they are continuously at the “L” level. The output of the disconnection determination circuit 63 in the second state is continuously at the “H” level because both the output of the voltage detection circuit 61 and the output of the bulb current detection circuit 62 are pulse signals. The output of the disconnection determination circuit 63 in the third state is
The output of 1 is a pulse signal, and the output of the bulb current detection circuit 62 is at the “H” level, so that a pulse signal is continuously generated. Therefore, disconnection of the electric bulb can be detected by detecting the generation of the pulse signal.

FIG. 5 is a circuit diagram showing a basic configuration example of a disconnection detecting device for a double filament light bulb, that is, a light bulb having two independent filaments.

As shown in FIG. 5, the double filament light bulb disconnection detecting device of this embodiment is a dual filament light bulb 8 having two independent filaments 84-1 and 84-2.
4, a power switch 81 for applying an AC power supply 80 to the dual filament light bulb 84, and a voltage detection circuit 82 connected in parallel to a power supply line and detecting a voltage, as in FIG.
And the same lamp current detection circuits 83-1 and 83-2 as in FIG. 4 which are connected in series to the respective filaments of the dual filament bulb 84 and detect the respective currents, and the dual filament bulbs using the respective outputs as inputs. The circuit 84 includes a disconnection determination circuit 85 for determining disconnection.

The voltage detection circuit 82 of FIG. 5 operates in the same manner as the voltage detection circuit of FIG. As a result, the voltage detection circuit 82
When an AC voltage is applied, the output is almost equal to the "L" level (saturated collector-emitter voltage) where the voltage is almost zero in the positive half-wave, and is almost equal to the power supply voltage "H" of the DC power supply in the negative half-wave. "Level pulse signal. On the other hand, when the power switch 81 is off, that is, when the AC voltage is not applied to the voltage detection circuit 82, the output of the voltage detection circuit 82 is continuously maintained at the “H” level.

The electric current detection circuits 83-1 and 8 for the electric bulb in FIG.
3-2 performs the same operation as the electric current detection circuit for the electric bulb in FIG. Here, the current detection circuits 83-1 and 83-2 for electric bulbs
Will be described in three states. The first state is a state in which the power switch 81 is off, that is, when no current is applied to the dual filament lamp 84, and both the outputs of the lamp current detection circuits 83-1 and 83-2 are at the “H” level. Become. The second state is the power switch 8
1 is on and the dual filament light bulb 84 is normally lit, an AC voltage is applied to the dual filament light bulb 84 and a current flows, and the outputs of the bulb current detection circuits 83-1 and 83-2 are The third state in which both pulse signals have the same timing is when one of the filaments 84-1 of the double filament bulb 84 is disconnected in the second state, and the output of the bulb current detection circuit 83-1 is: It goes to "H" level. However, the output of the bulb current detection circuit 83-2 holds the state of the pulse signal.

A pull-up resistor to which a DC voltage VCC of a DC power supply 86 is applied is connected to the output of each photocoupler of the voltage detection circuit 82 and the light bulb current detection circuits 83-1 and 83-2. This guarantees the "H" level.

The disconnection determination circuit 85 shown in FIG. 5 is constituted by a two-input NOR 93 having two outputs as inputs after connecting the same circuit as the disconnection determination unit of FIG. 1 for each filament. The output of the disconnection determination circuit 85 in the first state is the voltage detection circuit 82 and the current detection circuits 83-1 and 8 for the bulb.
Since both outputs of 3-2 become "H" level, they continuously become "L" level. Second state disconnection determination circuit 85
Are output from the voltage detection circuit 82 and the bulb current detection circuit 8.
Since both outputs of 3-1 and 83-2 become pulse signals, they continuously go to the “H” level. The output of the disconnection determination circuit 85 in the third state is such that the output of the voltage detection circuit 82 is a pulse signal, and the output of the current detection circuit 83-1 for the bulb is at the "H" level. Signal is continuously generated, while the current detection circuit 83-2
Is a pulse signal, the two-input AND92
Becomes "L" level, and as a result, the two-input NOR
A pulse signal is continuously generated at the output of the signal 93. Therefore,
By detecting the generation of this pulse signal, disconnection of the double filament light bulb can be detected.

Similarly, when only the filament 84-2 of the double filament lamp 84 is broken or when the filaments 84-1 and 84-2 of the double filament bulb 84 are broken simultaneously, the output of the disconnection determination circuit 85 is similarly determined. Is "
The pulse signal becomes a continuous pulse signal from H level. Therefore, by detecting this pulse signal, the disconnection of the double filament light bulb 84 can be detected.

[0042]

As described above, the contents of the invention corresponding to claim 1 are means for outputting a disconnection of an AC power supply LED lamp comprising one or a plurality of LED units to the outside as a pulse signal. And a disconnection detecting device capable of detecting disconnection of the LED lighting device.

A voltage detecting circuit according to a second aspect of the present invention includes a rectifying diode, a photocoupler driving circuit, and a photocoupler for detecting that AC power is applied to the LED lamp, and outputs the photocoupler with an output. A pulse signal is generated at the timing of the half-wave rectified waveform.
A disconnection detecting device capable of detecting disconnection of an LED lamp can be provided. Also, this voltage detection circuit has an AC voltage 1
If the voltage is 0 V or more, a stable pulse signal is generated, and therefore, it has a feature that it is extremely stable against voltage fluctuation of the AC power supply.

According to a third aspect of the present invention, there is provided a current detection circuit for detecting a current flowing through an LED unit in an LED lamp in which a single LED unit or a plurality of LED units are connected in parallel. It is composed of a circuit for driving the LED group and a current detection circuit including a photocoupler. The output of the voltage detection circuit outputs a pulse signal when a current flows through the LED group, and outputs "H" when no current flows. A disconnection detecting device capable of detecting disconnection of an LED lamp can be provided.

According to a fourth aspect of the present invention, there is provided a disconnection determination circuit comprising: a voltage detection circuit for an AC power supply LED lamp comprising one or a plurality of LED units;
A logic circuit that receives the outputs of a plurality of current detection circuits corresponding to the unit and determines the disconnection of the LED lamp. If a disconnection occurs, a pulse signal is obtained at the output of the disconnection determination circuit. Thus, a disconnection detection device capable of detecting disconnection of an LED lamp can be provided. Similarly, when two or more or all of the LED units are disconnected at the same time, a pulse signal is obtained at the output of the disconnection determination circuit.

According to a fifth aspect of the present invention, there is provided a simple L comprising a rectifying bridge, a current limiting resistor, and an LED group.
A simple LE that uses a voltage detection circuit, a simple LED current detection circuit, and a disconnection determination circuit to detect a disconnection of an ED lamp, and continuously generates a pulse signal at the output of the disconnection determination circuit when a disconnection occurs.
A disconnection detection device for a D lamp can be provided.

According to a sixth aspect of the present invention, there is provided a light bulb which uses a voltage detection circuit, a current detection circuit for a light bulb, and a disconnection determination circuit to continuously generate a pulse signal at the output of the disconnection determination circuit when the light bulb is disconnected. Can be provided.

The content of the invention corresponding to claim 7 is that when this disconnection detecting device is used for a signal lamp, disconnection can be detected when one of the two independent filament lamps is disconnected. Is transmitted to a centralized monitoring station of a traffic signal, thereby providing a disconnection detection device for a double filament bulb having two independent filaments, which has a feature of increasing the possibility of preventing complete extinguishing due to disconnection of a signal. As described above, each of the disconnection detecting devices according to claims 1 to 7 has a feature that the circuit configuration is simple and the size can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing waveforms of respective parts of the circuit shown in FIG.

FIG. 3 is a circuit diagram of one embodiment of the invention described in claim 5;

FIG. 4 is a circuit diagram of one embodiment of the invention according to claim 6;

FIG. 5 is a circuit diagram of one embodiment of the invention according to claim 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Power switch 3 Voltage detection circuit 4 Rectifier diode 5 Resistance 6 Transistor (NPN) 7 Transistor (PNP) 8 Diode 9 Resistance 10 Transistor (NPN) 11 Resistance 12 Photocoupler 13 Resistance 14 Rectification bridge 15 LED lamp 16- 1 to N LED group 17-1 to N Current detection circuit 18-1 to N LED unit 19 Transistor (NPN) 20 Resistance 21 Transistor (PNP) 22 Diode 23 Transistor (NPN) 24 Resistance 25 Resistance 26 Photocoupler 27 Resistance 28 Schmitt・ Trigger inverter 29 Resistance 30 Capacitor 31 Retrigger single shot circuit 32 2-input AND 33-1 to N Disconnection judgment unit 34 Multi-input OR 35 Schmitt trigger inverter 36 Disconnection judgment Circuit 37 AC power supply 38 Power switch 39 Voltage detection circuit 40 Rectification bridge 41 Simple LED current detection circuit 42 LED group 43 Current limiting resistor 44 Disconnection determination circuit 45 Transistor 46 Rectifier diode 47 Photocoupler drive circuit 48 Photocoupler 49 Resistance 50 Photocoupler Reference Signs List 51 resistance 52 simple LED lamp 53 Schmitt trigger inverter 54 retrigger single shot circuit 55 2-input AND 56 Schmitt trigger inverter 57 DC power supply 58 Light bulb 59 AC power supply 60 Power switch 61 Voltage detection circuit 62 Current detection for light bulb Circuit 63 Disconnection determination circuit 64 Rectifier diode 65 Photocoupler drive circuit 66 Photocoupler 67 Rectifier diode 68 Transistor 69 Resistance 70 Zener diode 71 Photocoupler 2 Resistance 73 Resistance 74 DC power supply 75 Resistance 76 Schmitt trigger inverter 77 Retrigger single shot circuit 78 2-input AND 79 Schmitt trigger inverter 80 AC power supply 81 Power switch 82 Voltage detection circuit 83 Light bulb current detection circuit (83 -1, 83-2) 84 Double filament light bulb (filament of 84-1, 84-2) 85 Disconnection determination circuit 86 DC power supply 87 Schmitt trigger inverter 88 Retrigger single shot circuit 89 2-input AND 90 Schmitt Trigger inverter 91 Retrigger single shot circuit 92 2-input AND 93 2-input NOR

Claims (7)

[Claims] 1. About several tens of LEs turned on by an AC power supply
One LED unit of an LED group in which D is connected in series and a drive circuit in which the LED group is connected in series (hereinafter referred to as an LED unit including both the LED group and its drive circuit), or a plurality of LED units in parallel A signal light and an illumination light (hereinafter referred to as L) using a plurality of connected LED units.
ED lamp), which detects an AC voltage applied to a rectifier bridge or a rectifier diode via a power switch, and generates a pulse signal as an output when the AC voltage is applied. A voltage detection circuit,
A current detection circuit that detects a current flowing through the LED unit through a rectifying bridge or a rectifying diode, and generates a pulse signal as an output when the current is flowing;
An LED lamp having a disconnection determination circuit that receives the output of each of the voltage detection circuit and the current detection circuit as input, logically determines disconnection detection of the LED unit, and detects disconnection of a plurality of LED units in a similar manner. Disconnection detection device The voltage detection circuit is connected in parallel to a power supply line immediately after a power supply switch, and a photocoupler drive circuit including a rectification function for driving a photocoupler diode, and a current flows through the photocoupler diode. 2. The photocoupler according to claim 1, further comprising: a photocoupler that outputs a pulse signal in a state where the pulse signal is applied, that is, in a state where an AC voltage is applied.
ED lamp disconnection detection device 3. The current detection circuit is a photocoupler connected in series to the LED unit and detects a current flowing through the LED unit. The current detection circuit converts the LED group into AC half-waves determined by the number of LEDs and the characteristics of the forward voltage. 2. A disconnection detecting device for an LED lamp according to claim 1, further comprising: a driving circuit of an LED group for flowing a current at a specific time equal to or higher than a voltage value of the LED group and a photocoupler for detecting a current flowing to the LED group. 4. The disconnection determination circuit performs disconnection determination of an LED unit by using respective outputs of the voltage detection circuit and one or a plurality of the current detection circuits as inputs.
With voltage applied to the group, one or more LEDs
2. The LE according to claim 1, further comprising a logic circuit for continuously outputting a pulse signal when the unit is disconnected and the current is cut off.
D light disconnection detection device 5. The simplest simple LED lighting device comprising an AC power supply, a power switch, a full-wave rectifier bridge, a current limiting resistor for limiting a current flowing through an LED group, and an LED group, and detecting disconnection of the LED. 2, a simple LED current detection circuit having a transistor connected in series to the LED lamp, and having a bias resistor and a photocoupler in parallel between the collector and the base of the transistor; A disconnection detection device for an LED lamp, comprising a disconnection determination circuit similar to that of claim 4, wherein an output of one or a plurality of said simple LED current detection circuits is input. 6. A disconnection detection device for a signal lamp and an illumination lamp (hereinafter referred to as a bulb lamp) using a bulb lit by an AC power supply, wherein the voltage detection circuit detects an AC voltage and flows to the bulb lamp. A rectifier diode that flows a negative half-wave of an alternating current and a transistor that flows a positive half-wave are connected in parallel, and a bias resistor and a photocoupler are connected in parallel between the collector and base of the transistor to detect the current flowing through the bulb lamp. And
When a current is flowing, the current detection circuit for a bulb lamp that generates a pulse signal as an output, and the respective outputs of the voltage detection circuit and the current detection circuit for the bulb lamp are input, and the disconnection determination of the bulb lamp is performed. This is a logic circuit that continuously outputs a pulse signal when the lamp is disconnected and the current is interrupted while AC voltage is applied to the lamp, and detects the disconnection of the lamp. Disconnection detecting device for light bulb lamp provided with disconnection determination circuit for logical determination 7. A disconnection detection of a double filament light bulb using a double filament light bulb having two independent filaments turned on by an AC power supply, wherein the voltage detection circuit and each of the two filaments flowing through the two filaments. The two current detection circuits for the bulb lamps for detecting current, the outputs of the voltage detection circuit and the two current detection circuits for the bulb lamps are input, and the disconnection of the double filament bulb is determined. A pulse signal is output continuously when one or two filaments of a double filament bulb are disconnected and the current of one or two filaments is cut off, with the AC voltage applied to the heavy filament bulb. Device for detecting the disconnection of a double-filament bulb lamp with a disconnection determination circuit for logically detecting the disconnection of a dual-filament bulb lamp