JPH08236280A - Lighting equipment - Google Patents

Abstract

(57) [Summary] [Purpose] Dimming control of lighting load by switching element
The switching element is turned on / off.
Whether or not the lighting load is connected is detected. [Structure] Switch between AC power supply AC and lighting load L
The plug element S is inserted. The switching element S has a capacitor
Sensor C₁And resistance R₁Snubber circuit with and connected in series is parallel
Connected. The lighting load L has a detection resistor R₂Connected in parallel
The voltage phase of the AC power supply AC and the detection resistor R₂Both ends of
The phase of the voltage is compared by the monitor circuit 5. Switch
The leakage current of the snubber circuit detects when the ching element S is off.
Outgoing resistance R ₂The phase of the voltage generated at both ends of the
If the voltage is more advanced than the voltage phase of
to decide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimmable lighting device,
In particular, the present invention relates to a lighting device that performs a light control operation from a distance in order to obtain a staging effect like stage lighting.

[0002]

2. Description of the Related Art Generally, in the stage lighting, the lighting direction and brightness of a lighting load for illuminating the stage or the vicinity of the stage is controlled by a light control device arranged in a separate room (far away) in order to obtain a staging effect. Moreover, the wiring between the light control device and the power supply and the lighting load can be freely performed by using an outlet provided on the stage. In such a usage environment in which the lighting load and the device for controlling the lighting load are separated from each other and the connection relationship of the lighting load can be freely changed, the lighting load is forgotten to be connected or the connected lighting load is out of range. Since the light control device side can easily know such things and the usability is improved, a configuration for detecting the no-load state of the output is required so that the device side controlling the lighting load can know these situations. ing.

In order to meet such requirements, as shown in FIG. 16, a triac (a thyristor or another power element may be used) between an AC power source AC and a lighting load L such as an incandescent lamp. Switching element S such as
By inserting a trigger signal from the trigger circuit 1 into the switching element S to control the phase,
In the lighting device in which the dimming control is performed, the current flowing between the switching element S and the lighting load L is changed by the current transformer C.
A configuration in which T is used for detection and the presence or absence of a lamp current to the lighting load L is detected by the current transformer CT is conceivable. Here, a snubber circuit, which is a series circuit of a capacitor C and a resistor R ₁ , is connected in parallel to the switching element S.

In this configuration, when the trigger circuit 1 generates a trigger signal for turning on the switching element S at a specific phase angle every half cycle of the current waveform of the AC power supply AC (see FIG. 17B), As shown in FIG. 17A, the switching element S is turned on from the rising time of the trigger signal to the next zero cross point of the current waveform of the AC power supply AC.
Therefore, if the lighting load L is connected, the current transformer C
At T, a current flows in the vertical line portion of FIG. 17 (b). On the other hand, when the lighting load L is not connected or the lamp is burnt out and there is no load, the current is not detected by the current transformer CT, so that the current is not detected as shown in FIG. 17C. In other words, if the lighting load L is connected, the lamp current is detected by the current transformer CT, and if the lamp current is not detected, it is determined that the lighting load L is not connected or the lamp of the lighting load L is burnt out. be able to.

On the other hand, in the state where the trigger signal is stopped and the switching element S is continuously kept off as shown in FIG. 18 (a), the current transformer CT supplies a current regardless of whether the lighting load L is connected or not. Is not detected (FIG. 18 (b) is a state where the lighting load L is connected, and FIG. 18 (c) is a no-load state). In short, in the circuit configuration shown in FIG. 16, it is determined whether or not the lighting load L is connected only during the period in which the trigger signal is generated and the dimming control is performed. Therefore, the lighting load L is determined based on the output of the current transformer CT. The current detection circuit 2 that detects the presence / absence of the L connection has a configuration that detects the current in synchronization with the ON period of the switching element S. As a result, in the state in which the lighting load L is not turned on, it is not detected that the lighting load L is unloaded even if the lighting load L is removed, and the lighting load L is connected even if the lighting load L is connected to the lighting load L. Since it is not possible to detect the connection of the lighting load L, it is necessary to energize the AC power supply AC to generate a trigger signal in order to know whether or not the lighting load L is connected.

By the way, in order to monitor the output to the lighting load L, a circuit configuration shown in FIG. 19 is considered. This is obtained by removing the current transformer CT and the current detection circuit 2 from the circuit shown in FIG. 16 and instead detecting the resistance R ₂ connected in parallel to the lighting load L and the voltage for detecting the voltage across the detection resistance R _2. The detection circuit 3 is added. Voltage detection circuit 3
Then, the output to the lighting load L is monitored by detecting the voltage applied to the lighting load L.

In the circuit configuration shown in FIG. 19, the trigger circuit 1
If the trigger signal is output from, the voltage detection circuit 3 can directly detect the voltage waveform applied to the lighting load L. On the other hand, the voltage waveform of the AC power supply AC is shown in FIG.
If the trigger circuit 1 does not generate the trigger signal as shown in FIG.
No voltage is detected by the voltage detection circuit 3 regardless of whether or not there is a connection (FIG. 20 (c) shows a state in which the lighting load L is connected, and FIG. 20 (d) shows a state in which the lighting load L is not connected. Represents). Here, the impedance of the lighting load L is smaller than the impedance of the snubber circuit.

If the detection resistor R ₂ does not exist, the voltage detection circuit 3 detects a voltage as shown in FIG. 20E when the lighting load L is not connected. This is due to the leakage current of the snubber circuit, and since the input impedance of the voltage detection circuit 3 is high, a high voltage is generated at the input end of the voltage detection circuit 3 due to the leakage current of the snubber circuit and the switching element S. Of. When such a voltage is generated, it is erroneously recognized as if a trigger signal is generated even though the trigger signal is not output. Therefore, in the above circuit, the detection resistor R ₂ smaller than the impedance of the snubber circuit is inserted so that the voltage is not detected by the voltage detection circuit 3 when the switching element S is off.

This circuit configuration detects whether or not the switching element S is controlled by the trigger signal, and of course cannot detect whether or not the lighting load L is connected. The above-mentioned ones are intended to detect whether or not the lighting load L is connected. However, even if the lighting load L or the like has a defective insulation, there is a danger of fire or the like, and it is necessary to know this. Therefore, as shown in FIG. 21, a dimmer (the switching element S, the snubber circuit, and the trigger circuit 1 are collectively called a dimmer) from the AC power supply AC.
It is conceivable to individually provide the leakage detection circuits 6 on the path for supplying power to the lighting load L through. With such a configuration, even if there are many lighting loads L, each lighting load L
If the leakage detection circuit 6 is provided for each, the lighting load L or the dimmer VB in which the leakage has occurred can be specified.
Since a large number of leakage detection circuits 6 are required, the cost increases and the storage space becomes large.

On the other hand, as shown in FIG. 22, one leakage detecting circuit 6 is inserted between a parallel circuit in which a large number of circuits connecting the dimmer VB and the lighting load L are connected in parallel and the AC power supply AC. Even with the configuration, it is possible to detect the occurrence of the leakage and prevent the accident, but in this configuration, it is necessary to determine which of the lighting load L and the circuit including the dimmer VB has the leakage. However, there is a problem that it takes time to find the leakage point.

[0011]

As described above, only with the circuit configuration for detecting the current flowing in the lighting load L and the voltage applied to the lighting load L, it is determined whether the lighting load L is connected or not by turning on the switching element S. It is not possible to detect whether the lighting load L is connected or not, regardless of whether the switching element S is on or off. Is required to do so.

When a large number of the lighting loads L and the dimmers VB are used as a structure for detecting an electric leakage occurring when the lighting loads L and the dimmers VB fail to prevent an accident such as a fire from occurring. It is demanded that the occurrence of electric leakage can be reliably detected, the location of the electric leakage can be easily found, and the storage space can be made relatively small.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a structure in which a lighting element is dimming-controlled by a switching element inserted between an AC power source and the lighting load. It is possible to detect the presence or absence of the connection of the lighting load regardless of whether it is on or off, and to provide a lighting device that can detect the leakage point reliably and easily while saving space with a relatively simple configuration. To do.

[0014]

According to a first aspect of the present invention, there is provided a switching element inserted between an AC power source and a lighting load, and a snubber circuit connected in parallel with the switching element.
A trigger circuit that controls the power supply to the lighting load by controlling the conduction phase of the switching element, a detection resistor that is connected in parallel to the lighting load and that can detect the voltage across the snubber circuit due to leakage current, and a detection resistor. And a monitor circuit for comparing the phase of the voltage across the resistor and the voltage phase of the AC power supply and determining no load when the phase of the voltage across the detection resistor is more advanced than the voltage phase of the AC power supply. Characterize.

According to a second aspect of the present invention, a current detection circuit for detecting a current supplied to the lighting load is provided, and the monitor circuit comprises:
Even if the voltage across the detection resistor is detected but the phase is not advanced with respect to the voltage phase of the AC power supply, if no current is detected by the current detection circuit of the AC power supply, it is judged as no load. It is characterized by doing.

According to another aspect of the present invention, a diode bridge connected in series with the detection resistor and a photocoupler having a light emitting element that lights up by receiving the output of the diode bridge are provided, and the output of the photocoupler is used as a monitor circuit. It is characterized by inputting. According to a fourth aspect of the present invention, a photocoupler in which a pair of light emitting elements connected in anti-parallel is connected in series to a detection resistor is provided, and the output of the photocoupler is input to the monitor circuit.

According to another aspect of the present invention, a breaker inserted between the connection point between the detection resistor and the switching element and the lighting load and a voltage detection circuit for detecting the voltage across the lighting load are provided. If the voltage is not detected by the voltage detection circuit while the voltage across the detection resistor is being detected, it is determined that the breaker is off. . According to a sixth aspect of the invention, in a lighting device in which a plurality of series circuits of a dimmer and a lighting load are connected in parallel to one AC power source, a plurality of dimmers and a lighting load are connected in series. A leakage detection circuit that detects leakage due to unbalanced current is provided between the parallel circuit and the AC power supply, and an output detection circuit that detects the output voltage is provided for each dimmer, and the leakage detection circuit detects the leakage. In this case, each dimmer is provided with a determination circuit for determining that a leakage current has occurred in the series circuit of the dimmer and the lighting load whose output voltage is detected by the output detection circuit. .

In the invention of claim 7, the output state of each dimmer is sampled and stored in the output detection circuit, and when the leakage detection by the leakage detection circuit is performed, the output detection circuit whose output state changes before and after the occurrence of the leakage is provided. It is characterized in that it is judged that an electric leakage has occurred in the series circuit of the connected dimmer and the lighting load. In a lighting device in which a plurality of series circuits of a dimmer and a lighting load are connected in parallel to one AC power supply, a plurality of dimmers and a lighting load are connected in series. Between the parallel circuit of each other and the AC power supply, the leakage detection circuit that detects the leakage due to the unbalanced current is provided, and the output detection circuit that detects the output voltage is provided for each dimmer to illuminate each dimmer. A means for selectively inputting a dimming signal for setting the dimming level of the load and a confirmation signal for turning off the lighting load is provided, and the dimming power is supplied to the lighting load when a leakage is detected in the leakage detection circuit. Confirmation signals are sequentially input to the control unit to turn them off temporarily, and when the leakage detection circuit no longer detects leakage, it is determined that there is leakage in the series circuit of the lighting load and the dimmer that was turned off. Control means to keep lighting load off Characterized in that was.

According to a ninth aspect of the present invention, the leakage detection circuit detects a zero-cross point of the AC power source and inputs a confirmation signal to each dimmer at the time of detecting the zero-cross point. According to the tenth aspect of the invention, when the leakage detection circuit detects a leakage during the period in which the lighting load is turned off by the confirmation signal, the dimmer connected in series to the lighting load receives the dimming signal at the time of the leakage detection. It is characterized by inputting and inputting a confirmation signal to another dimmer at the next zero cross point.

[0020]

According to the invention of claims 1 to 5, even if the switching element is off, the leakage current of the snubber circuit can be detected as the voltage across the detection resistor. Whether or not the lighting load is connected can be known from the relationship with the voltage phase of the AC power supply. In other words, if a lighting load is connected, almost no current will flow through the detection resistor, so there is no phase difference with the voltage phase of the AC power supply, and there will be no detection when the lighting load is not connected or there is no load such as a lamp burnout. The no-load state of the lighting load can be detected by seeing the phase relationship with the voltage phase of the power supply voltage when a current flows through the application resistor. Further, when the breaker is used as in the structure of claim 5, it is possible to know the on / off state of the breaker by detecting the voltage before and after the breaker.

According to the sixth to tenth aspects of the invention, only one leak detection circuit is provided for the plurality of dimmers and the lighting load at a time, and the output detection is provided for each dimmer. By recognizing the leakage state of the series circuit of each dimmer and each lighting load together with the circuit, the circuit in which the leakage occurs can be specified. Moreover, the size can be reduced as compared with the case where the leakage detection circuit is provided for each series circuit of each dimmer and each illumination load.

In particular, as in the structure of the invention of claim 10, in the one in which a confirmation signal is inputted to each dimmer at the zero-cross point of the AC power source to turn off the illumination load once, the illumination load is turned off by the confirmation signal. If the dimming signal is applied to the dimmer immediately after the leakage is detected by the leakage detection circuit during the period, the lighting load is turned off to detect the leakage and the period is shortened as much as possible. Therefore, it is possible to suppress the flicker of the output of the lighting load.

[0023]

【Example】

(Embodiment 1) As shown in FIG. 1, in this embodiment, in addition to the first voltage detection circuit 3 for detecting the voltage across the lighting load L as shown in FIG. Whether or not the lighting load L is connected is determined by adding the second voltage detection circuit 4 and determining the phase difference between the voltage waveforms detected by the first voltage detection circuit 3 and the second voltage detection circuit 4. A monitor circuit 5 for judging is added.

Explaining in more detail, like a commercial power source
AC power supply AC for triac (thyristor or other
Power element of the above) and a switching element S such as
Connect a series circuit with the lighting load L to connect the switching element S
Capacitor C₁And resistance R ₁Is a series circuit with
Connect the circuit in parallel. The lighting load L has a detection resistor R ₂
Are connected in parallel, and in the first voltage detection circuit 3, the detection resistor R
₂The voltage across both ends of the
The power supply voltage of the power supply AC is detected. Here, the detection resistor R
₂Is the snubber circuit when the lighting load L is not connected.
Resistance R for detection due to leakage current₂Voltage across both ends of
, The relationship with the snubber circuit impedance is set.
Be done. Further, the lighting load L is an incandescent light bulb and is a snubber circuit.
Is set to have a higher impedance than the lighting load L. One
Mari, detection resistor R₂Is different from the conventional configuration shown in FIG.
Is set to a value such that
The impedance to be set is set too high.

Further, the phase difference between the voltage waveforms detected by the second voltage detection circuit 3 and the second voltage detection circuit 4 is detected by the monitor circuit 5, so that the monitor circuit 5 detects the lighting load based on the phase difference. Judge whether L is connected or not. The switching element S is turned on by the rising edge of the trigger signal generated by the trigger circuit 1 every half cycle of the current waveform of the AC power supply AC at a specific phase angle, and turned off at the zero cross point of the current waveform of the AC power supply AC.

Next, the operation of the above circuit will be described. Now
When the AC power supply AC has a voltage waveform as shown in FIG. 2A, the second voltage detection circuit 4 binarizes the voltage by an appropriate threshold Th ₂ , and the voltage of the AC power supply AC as shown in FIG. It is converted into a binary signal in which only the phase information of the waveform is extracted. Here, it is assumed that the trigger signal is stopped and the switching element S is kept off as shown in FIG. At this time, the leakage current of the snubber circuit and the switching element S flows into the lighting load L, but the impedance of the snubber circuit is set sufficiently higher than that of the lighting load L.
As shown in (d), almost no voltage appears across the illumination load L.

On the other hand, when the illumination load L is lighting load not connected L is in the no-load a lamp-out, the voltage waveform as shown in Figure 2 across the sense resistor R ₂ (e) Appears. The first voltage detection circuit 3 binarizes this voltage by using an appropriate threshold value Th ₁ and converts it into a binary signal containing only the phase information of the voltage across the detection resistor R ₂ as shown in FIG. To do. By the way, when the switching element S is off under no load, a closed loop is formed from the AC power source AC through the capacitor C ₁ and the resistor R _{1 of the} snubber circuit and the detection resistor R ₂ , and therefore the detection resistor R ₂ The voltage waveform of the voltage between both ends of the phase becomes a phase advance with respect to the voltage waveform of the AC power supply AC. Therefore, the monitor circuit 5 compares the phase difference between the binary signal output from the first voltage detection circuit 3 and the binary signal output from the second voltage detection circuit 4,
When the binary signal output from the second voltage detection circuit 3 is in phase advance with respect to the binary signal of the voltage detection circuit 4 of FIG.

In the monitor circuit 5, the second voltage detection circuit 4
The binary signal as shown in FIG. 2 (f) output from the first voltage detection circuit 3 falls during the period from the rising to the falling of the binary signal as shown in FIG. 2 (b). And the voltage waveform across the lighting load L is AC power supply AC
It can be determined that the phase is advanced with respect to the voltage waveform of.

On the other hand, when the trigger signal is output from the trigger circuit 1, if the lighting load L is connected,
The voltage is not detected by the first voltage detection circuit 3 during the off period of the switching element S, and the voltage is detected during the first voltage detection period 3 during the on period of the switching element S. That is, the voltage waveform detected by the first voltage detection circuit 3 substantially corresponds to ON / OFF of the switching element S. Therefore, generally speaking, the binary signal output from the first voltage detection circuit 3 does not rise at the time of rising of the binary signal output from the second voltage detection circuit 4, and the switching element S It will rise after the time corresponding to the phase angle to be turned on has elapsed.

When the trigger signal is output from the trigger circuit 1 and there is no load, the binary signal output from the second voltage detection circuit 4 is the same as when there is no load while the trigger signal is stopped. The binary signal output from the first voltage detection circuit 4 has risen before the rising edge of. As described above, if the lighting load L is connected regardless of the output of the trigger signal from the trigger circuit 1, the first signal is generated at the rising time point of the binary signal output from the second voltage detection circuit 4. If the lighting load L is connected, the binary signal output from the voltage detection circuit 3 of FIG. 1 does not rise, and the first voltage is output at the rising time of the binary signal output from the second voltage detection circuit 4. 2 output from the detection circuit 3
The value signal is rising. When there is no load, the voltage waveform input to the first voltage detection circuit 3 is the second waveform.
Since the phase of the voltage waveform input to the voltage detection circuit 4 is advanced, the output voltage of the first voltage detection circuit 3 before the falling of the binary signal output from the second voltage detection circuit 4 The value signal falls. As a result, by determining the phase difference between the outputs of the first voltage detection circuit 3 and the second voltage detection circuit 4, in the monitor circuit 5, whether or not the lighting load L is connected regardless of whether the switching element S is on or off. Can know.

By the way, a pilot lamp for indicating whether or not the AC power source AC is energized may be provided, but the pilot lamp can be turned off by controlling the switching element S to be off by the monitor circuit 5 when there is no load. (Embodiment 2) In this embodiment, as shown in FIG.
In addition to the above configuration, the current flowing through the lighting load L
The current is detected by the current detection circuit 2 via the monitor, and the monitor circuit 5 also uses the state obtained by the current detection circuit 2.

That is, in the configuration of the first embodiment, the dimming level is low and the off period of the switching element S is long when there is no load in the state where the trigger signal is generated and the switching element S is turned on / off. In such a case, the effect of the phase lead by the snubber circuit appears strongly, so that the binary signal output from the first voltage detection circuit 3 at the time of rising of the binary signal output from the second voltage detection circuit 4 is It has already risen, and thereafter, the binary signal output from the first voltage detection circuit 3 falls before the binary signal output from the second voltage detection circuit 4 falls. That is, the monitor circuit 5 can detect the no-load by the same determination method as when the switching element S is kept off without generating the trigger signal.

On the other hand, when the dimming level is high and the off period of the switching element S is short, the effect of phase advance by the snubber circuit is weakened. For example, for the voltage waveform of the AC power supply AC as shown in FIG. If the switching element S is continuously turned on as shown in FIG. 4B, the effect of phase advance by the snubber circuit does not occur regardless of the connection of the lighting load L (FIG. 4). (C) is when the lighting load L is connected, and FIG. 4 (d) is when there is no load). That is, it is not guaranteed that the binary signal output from the first voltage detection circuit 3 will rise before the binary signal output from the second voltage detection circuit 4 rises, and the binary signal output from the voltage detection circuit 4 will not output. It is not guaranteed that the binary signal output from the first voltage detecting circuit 3 will fall before the falling of the binary signal. That is, when the switching element S is turned on / off by the trigger signal, the first
In some cases, the no-load state of the lighting load L cannot always be detected only by the phase difference between the binary signals output from the voltage detection circuit 3 and the second voltage detection circuit 4.

Therefore, in this embodiment, the current detection circuit 2 is used in combination with the structure of the first embodiment. If the current flowing through the lighting load L is detected, the presence or absence of the connection of the lighting load L when the switching element S is turned on can be detected as described in the related art. Therefore, the current flowing through the lighting load L by the current transformer CT. Is detected and the presence or absence of this current is detected by the current detection circuit 2 and used in the judgment by the monitor circuit 5, it becomes possible to detect no load even during the period when the dimming level is high. That is, when the switching element S is continuously turned on as shown in FIG. 4, if the lighting load L is connected, the current is detected as shown in FIG. Since the current is not detected as in (1), it is possible to determine whether or not the lighting load L is connected by using the current together when it cannot be determined only by the voltage. As described above, in the monitor circuit 5, it is possible to determine whether or not the lighting load L is connected at all dimming levels by using not only the voltage but also the current. Other configurations and operations are the same as those of the first embodiment.

[0035] (Embodiment 3) In the above embodiments, the first voltage detection circuit 3, although not detect the voltage across the sensing resistor R _2, as shown in FIG. 5, the sensing resistor R ₂ The diode bridge DB is connected in series, the light emitting element PE ₁ of the photocoupler PC ₁ is connected to the output end of the diode bridge DB, and the light receiving element PR of the photocoupler PC ₁ is connected.
_A signal corresponding to the binary signal may be extracted from ₁ . In this circuit configuration, the voltage across the detection resistor R ₂ is not detected, but this configuration also detects the voltage across the illumination load L.

That is, if the lighting load L is connected, a current flows through the lighting load L, so that the photocoupler PC ₁
Emitting element PE ₁ of not lit, the lighting load L connected when not (no load) to the resistor for detecting leakage current flowing through the snubber circuit R ₂ and the diode bridge D
It flows to B and the light emitting element PE ₁ is turned on. Here, since the light receiving element PR ₁ outputs a binary signal in accordance with the lighting period of the light emitting element PE ₁ , a signal similar to the binary signal shown in the first embodiment can be obtained.

The other structure of this embodiment is the same as that of the first embodiment, and the second voltage detection circuit 4 and the monitor circuit 5 are not shown in the figure, but they are provided similarly to the first embodiment. Thus, phase lead angle with respect to the AC power source AC voltage waveform of the voltage applied to the light emitting element PE ₁ of the photocoupler PC ₁ theta
And the applied voltage (effective value) V can be expressed as in Equation 1.

[0038]

[Equation 1]

Now, assume that the capacitor C ₁ is 0.1 μF, the resistors R ₁ and R ₂ are 1 kΩ and 10 kΩ, respectively, and the current conversion efficiency (ratio of output current to input current) of the photocoupler PC ₁ is 50%. Light receiving element P of PC ₁
When a current of 1 mA or more flows through R ₁ , the monitor circuit 5 judges that there is an output. At this time, since the input current needs to be 2 mA or more, the diode bridge D
If the voltage drop between B and the light emitting element PE ₁ is 3V, the voltage applied to the series circuit (illumination load L) of the resistor R ₂ and the diode bridge DB should be 23V or more.

For example, the AC power supply AC is 100V60H
z, the lead angle θ and the applied voltage V are 67 degrees and 35 V, respectively, when the capacitor C ₁ and the resistors R ₁ and R ₂ are set to the above values. Is 0 to 85 degrees and 141 to 180 degrees, the monitor circuit 5 determines that there is an output. That is, it is determined that the binary signal output from the first voltage detection circuit 3 is output (rising) before the rising of the binary signal output from the second voltage detection circuit 4, and the binary signal rises. It is judged that there is no output (falling) before falling. As is clear from the above description, the lead angle θ and the output voltage V can be adjusted by appropriately setting the capacitor C1 and the resistors R ₁ and R ₂ .

(Embodiment 4) As shown in FIG. 6, this embodiment is a configuration example of the first voltage detection circuit 3 and uses a diode bridge DB, as in the embodiment 3 shown in FIG. Instead, two light emitting elements PE consisting of light emitting diodes
₁₁ and PE ₁₂ are connected in anti-parallel, and the light emitting elements PE ₁₁ and PE ₁₂ are connected.
Is connected in series to the detection resistor R ₂ . This configuration also operates similarly to the third embodiment. Further, other configurations and operations are similar to those of the third embodiment.

(Embodiment 5) This embodiment is an example in which a breaker NCB is inserted between a switching element S and a lighting load L as shown in FIG. 7, and a voltage is detected before and after the breaker NCB. This makes it possible to detect whether the breaker NCB is on or off. That is, in the configuration of the fourth embodiment shown in FIG. 6, the breaker N
CB is inserted between the connection point between the switching element S and the detection resistor R ₂ and the illumination load L, and further, as a voltage detection circuit, the detection resistor R ₃ and the photocoupler PC ₂ are provided in parallel with the illumination load L. A series circuit of the light emitting elements PE ₂₁ and PE ₂₂ is connected to obtain a binary signal from the light receiving element PR ₂ of the photocoupler PC ₂ . The light emitting elements PE ₂₁ and PE ₂₂ are light emitting diodes and are connected in antiparallel. Other configurations are the same as those in the fourth embodiment.

Now, when the breaker NCB is turned off, the binary signal from the photocoupler PC ₁ is the same as when there is no load, but no voltage is applied to the light emitting elements PE ₂₁ and PE ₂₂ of the photocoupler PC _2. Turn off continuously. That is, no output signal is generated from the photocoupler PC ₂ .
On the other hand, if the breaker NCB is turned on, since the output of both the photocoupler PC _1, PC ₂ will be equal, by comparing the outputs of the photo-coupler PC _1, PC _2, for detecting the on-off breaker NCB It is possible. Other configurations and operations are similar to those of the fourth embodiment. Further, in this embodiment, a photocoupler PC similar to that of the fourth embodiment is used.
_{Although 1} and PC ₂ are adopted, the diode bridge DB and the photocouplers PC ₁ and PC ₂ may be used together as in the third embodiment.

(Embodiment 6) In this embodiment, as shown in FIG. 8, a lighting load L and a dimmer (hereinafter, a snubber circuit which is a series circuit of a switching element S, a capacitor C ₁ and a resistor R ₁ ). , The trigger circuit 1 is collectively called a dimmer)
An example in which a plurality of VBs are provided is shown. An output detection circuit 7 for detecting the output state of the dimmer VB is provided in each lighting load L.
It is provided between and. In the output detection circuit 7, the dimmer VB
Of the lighting load L is detected for each dimmer VB
If the output state of the dimmer VB changes while being connected to, it is determined that the connected lighting load L may be leaked. The output detection circuit 7 may have the same configuration as the voltage detection circuit 3 in each of the above-described embodiments.

On the other hand, a parallel circuit in which a series circuit of a dimmer VB and a corresponding lighting load L are connected in parallel to each other and an AC power source A
A leakage detection circuit 6 is inserted between C and C. The leakage detection circuit 6 detects the occurrence of leakage in the lighting load L or the dimmer VB by detecting the imbalance of the currents of the two wires of the AC power supply AC. Further, each lighting load L is provided with a determination circuit 8 for detecting the presence or absence of leakage in each lighting load L based on both outputs of the leakage detection circuit 6 and the output detection circuit 7.
The determination circuit 8 has a configuration as shown in FIGS. 9A and 9B, and it is possible that any one of the output detection circuits 7 detects a change in the output of the dimmer VB to cause a leakage. When the leakage is detected in the leakage detection circuit 6 while the determination is made, the AND circuit AND ₁ to the D flip-flop FF ₁ are used so that it can be determined that the leakage has occurred. Therefore, when any one of the determination circuits 8 reports the occurrence of the leakage, it can be determined that the corresponding lighting load L has the leakage.

The operation will be described with reference to FIG. The output detection circuit 7 always detects the output state of each dimmer VB (sampling is performed at regular time intervals) and stores the detected value (S6, S13). If the connected lighting load L has a defective insulation, the leakage detection circuit 6 detects the leakage (S
1) sequentially input to each determination circuit 8 (S2, S
7, S8), and the presence or absence of a change in the output of each output detection circuit 7 is detected (S3, S4). Here, if the change with leakage is input from the output detection circuit 7, the corresponding lighting load L
A warning is issued from the determination circuit 8 corresponding to the occurrence of the electric leakage (S5).

On the other hand, when the dimming device VB is controlled so that the lighting load L is turned off, when the leakage is eliminated, the determination circuits 8 are sequentially input (S9, S14, S1).
5) When it is confirmed that the lighting load L is turned off by comparing the output values of the output detection circuit 7 during the occurrence of the electric leakage and after the electric leakage is extinguished (S10, S11), the electric leakage warning is issued. Yes (S12).

By the above operation, the output detection circuit 7 and the determination circuit 8 formed of small parts are provided without providing the leakage detection circuit 6 using a large part such as a current transformer for each lighting load L. Since it is provided only for each lighting load L, the size can be reduced as compared with the conventional configuration while enabling the presence / absence of leakage to be determined for each lighting load L.

In the actual earth leakage detection circuit 6, as shown in FIG. 11, the two wires from the AC power supply AC are passed through the toroidal core 15, and the secondary winding 1 wound around the toroidal core 15 is provided.
The output of 6 may be used to detect the unbalanced current caused by the leakage. Further, the output detection circuit 7 is the same as that of the third embodiment.
It is possible to use the same configuration as the voltage detection circuit 3 shown in FIG. In addition, by providing the second voltage detection circuit 4 and the monitor circuit 5 in the circuit shown in FIG. 11, not only leakage detection but also determination of no load can be performed. further,
Even with the configuration in which the breaker NCB is inserted as in the fifth embodiment, the leakage detection can be performed by adding the leakage detection circuit 6 and the determination circuit 8 having the same circuits as those in the fifth embodiment.

(Embodiment 7) In this embodiment, as shown in FIG. 12, a dimming signal for setting the generation timing of the trigger signal 1 in the trigger circuit to a desired phase angle is provided to each dimmer VB. A dimming signal generating circuit 10 for outputting, a confirmation signal generating circuit 11 for generating a confirmation signal for turning off the switching element S to turn off the illumination load L, and one of the dimming signal and the confirmation signal to the dimmer VB. Switching circuit 1 for selectively inputting
2 and. Further, similarly to the sixth embodiment, a leakage detection circuit 6 inserted between a parallel circuit in which a plurality of series circuits of a dimmer VB and a lighting load L are connected in parallel and an AC power supply AC,
And an output detection circuit 7 for detecting the output of the dimmer VB. The switching circuit 12 is sequentially switched by the leakage detection circuit 6.

That is, as shown in FIG. 13, when the lighting load L having a defective insulation is connected and the leakage is detected by the leakage detecting circuit 6 (S1), the leakage detecting circuit 6 causes the output detecting circuit 7 to operate.
A confirmation signal is input to the dimmer VB by sequentially switching the switching circuit 12 corresponding to each lighting load L that is being supplied with power based on the output of (S2, S3, S8, S9). When the output from the dimmer VB to the lighting load L is stopped by the confirmation signal (S4) and the leakage is also eliminated (S6), it can be determined that the lighting load L is leaking. The lighting load L is turned off, and thereafter, the lighting load L is kept turned off until a recovery operation is performed (S
7). Here, since the leakage current changes according to the voltage change of the AC power supply AC, it is determined for a half cycle of the voltage waveform of the AC power supply AC (S5). With this configuration, if there is no leakage at the same time for a plurality of lighting loads L, it is possible to identify the lighting load L at which the leakage has occurred. Other configurations and operations are similar to those of the sixth embodiment.

(Embodiment 8) In the configuration of Embodiment 7, as the switching element S of the dimmer VB, one that does not turn off immediately with the stop of the trigger signal, such as a triac or a thyristor (of self-extinguishing ability). However, even if an attempt is made to turn off the switching element S by inputting a confirmation signal, the switching element S cannot be turned off until the current waveform of the AC power supply AC next passes the zero cross point. That is, there is a time delay from the input of the confirmation signal to the dimmer VB until the power supply to the lighting load L is stopped.

Therefore, in the present embodiment, the timing for giving the confirmation signal to the dimmer VB is set immediately before the zero cross point of the current waveform of the AC power supply AC, so that the above-mentioned time delay does not occur and the leakage detection is performed. Is increasing the accuracy of. In short, as shown in FIG. 14, FIG.
In the operation shown in FIG. 2, if it is determined in step S3 that the lighting load L is being supplied with power, the process of detecting the zero cross point of the current waveform of the AC power supply AC is inserted in step S4. In this way, the leakage detection circuit 6 detects the zero-cross point of the current waveform of the AC power supply AC (actually immediately before the zero-cross point), and inputs a confirmation signal to the dimmer VB at that time (S5). The switching element S can be turned off immediately after the confirmation signal is input. By adopting such a processing procedure, one lighting load L can be inspected for each cycle of the AC power supply AC. Other configurations and operations are similar to those of the seventh embodiment.

(Embodiment 9) If the processing procedure of the embodiment 8 is adopted, even if the electric leakage occurs even when the lighting load L is turned on (for example, when the stage lighting is actually performed), other It is possible to turn off only the lighting load L in which the leakage has occurred, with almost no effect on the lighting load L. However, since the power supply to each lighting load L is stopped for half a cycle of the AC power supply AC for detecting the leakage, a slight flicker occurs in the light output even with the normal lighting load L.

The present embodiment is intended to reduce such flicker, and steps S6 and S7 are changed and step S9 is newly added to the processing procedure of the eighth embodiment. That is, in order to determine whether or not the electric leakage has been eliminated, during the detection of each half cycle of the AC power supply AC for each dimmer VB (that is, a confirmation signal is given to each dimmer VB to turn off the lighting load L). If a leak is detected (while the light is being turned on), it can be determined that there is no leak in the lighting load L (S6, S7). Therefore, with respect to the dimmer VB corresponding to the lighting load L Controls the switching circuit 12 so that the dimming signal is input immediately after the leakage is detected (S).
9). If such a process is performed, a dimmer V is input so that a dimming signal is input assuming that no leakage has occurred.
With the lighting load L corresponding to B, the normal operation is immediately performed, so that the influence on the output is reduced and the flicker can be significantly improved. Further, a confirmation signal is given to the next dimmer VB at the time of detecting the next zero cross point.

In the configurations of the seventh to ninth embodiments, when the plurality of lighting loads L are simultaneously leaked, the lighting load L causing the leak cannot be specified. If all lighting loads L are turned off and then all lighting loads L are turned on, it is possible to detect the presence or absence of leakage for each lighting load L. Such processing is an effective method for detecting an electric leakage when the lighting load L is not in use.

[0057]

According to the inventions of claims 1 to 5, the leakage current of the snubber circuit can be detected as the voltage across the detection resistor even when the switching element is off. Whether or not the lighting load is connected can be known from the relationship with the voltage phase of. In other words, if a lighting load is connected, almost no current will flow through the detection resistor, so there is no phase difference with the voltage phase of the AC power supply, and there will be no detection when the lighting load is not connected or there is no load such as a lamp burnout. There is an advantage that the no-load state of the lighting load can be detected by seeing the phase relationship with the voltage phase of the power supply voltage when a current flows through the application resistor. Also,
When the breaker is used as in the configuration of claim 5, it is possible to know the on / off state of the breaker by detecting the voltage before and after the breaker.

According to the sixth to tenth aspects of the present invention, only one leak detection circuit is provided for a plurality of dimmers and a lighting load at a time, and an output detection circuit provided for each dimmer is combined. By recognizing the leakage status of the series circuit of each dimmer and each lighting load, it is possible to identify the circuit where the leakage is occurring, and moreover, the leakage detection circuit is connected to each dimmer and each lighting load. There is an advantage that the size can be reduced as compared with the case where each of the series circuits is provided. In particular, claim 10
As in the configuration of the invention, in the one in which the confirmation signal is input to each dimmer at the zero-cross point of the AC power source to turn off the lighting load once, in the period when the lighting load is turned off by the confirmation signal, the leakage detection circuit If a dimming signal is applied to the dimmer immediately after the leakage is detected to restore it, the period during which the lighting load is turned off to detect the leakage can be shortened as much as possible. There is an effect that flicker can be suppressed.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment.

FIG. 2 is an operation explanatory diagram of the first embodiment.

FIG. 3 is a circuit diagram showing a second embodiment.

FIG. 4 is an operation explanatory diagram of the second embodiment.

FIG. 5 is a circuit diagram showing a third embodiment.

FIG. 6 is a circuit diagram showing a fourth embodiment.

FIG. 7 is a circuit diagram showing a fifth embodiment.

FIG. 8 is a block diagram showing a sixth embodiment.

FIG. 9 is a diagram illustrating an example of a determination circuit used in a sixth embodiment.

FIG. 10 is an operation explanatory diagram of the sixth embodiment.

FIG. 11 is a circuit diagram showing a sixth embodiment.

FIG. 12 is a block diagram showing a seventh embodiment.

FIG. 13 is an explanatory diagram of the operation of the seventh embodiment.

FIG. 14 is an explanatory diagram of the operation of the eighth embodiment.

FIG. 15 is an operation explanatory diagram of the ninth embodiment.

FIG. 16 is a circuit diagram showing a conventional example.

FIG. 17 is an operation explanatory diagram of a conventional example.

FIG. 18 is an operation explanatory diagram of a conventional example.

FIG. 19 is a circuit diagram showing another conventional example.

FIG. 20 is an operation explanatory diagram of the conventional example shown in FIG. 19;

FIG. 21 is a block diagram showing another conventional example.

FIG. 22 is a block diagram showing still another conventional example.

[Explanation of symbols] 1 trigger circuit 2 current detection circuit 3 voltage detection circuit 4 voltage detection circuit 5 monitor circuit 6 leakage detection circuit 7 output detection circuit 8 determination circuit AC AC power supply C ₁ capacitor L lighting load R ₁ resistance R ₂ resistance S Switching element VB dimmer

Claims (10)

[Claims] 1. A power supply to a lighting load is controlled by controlling a switching element inserted between an AC power supply and a lighting load, a snubber circuit connected in parallel to the switching element, and a conduction phase of the switching element. And a detection resistor that is connected in parallel to the lighting load and that can detect the voltage across the snubber circuit due to leakage current, and the phase of the voltage across the detection resistor and the voltage phase of the AC power supply are compared for detection. An illumination device, comprising: a monitor circuit that determines that there is no load when the voltage across the resistor is more advanced than the voltage phase of the AC power supply. 2. A current detection circuit for detecting a current supplied to a lighting load is provided, and the monitor circuit detects the voltage across the detection resistor, but its phase is advanced with respect to the voltage phase of the AC power supply. The illuminating device according to claim 1, wherein even when it is not possible to detect the above, it is determined that there is no load when the current is not detected by the current detection circuit of the AC power supply. 3. A diode bridge connected in series with a detection resistor, and a photocoupler having a light emitting element that lights up by receiving the output of the diode bridge are provided, and the output of the photocoupler is input to a monitor circuit. The lighting device according to claim 1 or 2. 4. A photocoupler in which a pair of light emitting elements connected in antiparallel are connected in series to a detection resistor, and the output of the photocoupler is input to a monitor circuit. 2. The lighting device according to 2. 5. A breaker inserted between the connection point between the detection resistor and the switching element and the lighting load, and a voltage detection circuit for detecting the voltage across the lighting load are provided, and the monitor circuit has both ends of the detection resistor. The lighting device according to claim 1 or 2, wherein the breaker is determined to be off when the voltage is not detected by the voltage detection circuit when the voltage is detected. 6. A lighting device in which a plurality of series circuits of a dimmer and a lighting load are connected in parallel to one AC power source, and a series circuit of a plurality of dimmers and a lighting load is connected to each other. When a leakage detection circuit that detects leakage due to an unbalanced current is provided between the parallel circuit and the AC power supply, and an output detection circuit that detects the output voltage is provided for each dimmer, and when leakage is detected by the leakage detection circuit An illuminating device characterized in that each dimmer is provided with a judging circuit for judging that electric leakage has occurred in a series circuit of a dimmer and an illumination load whose output voltage is detected by an output detection circuit. . 7. The output detection circuit samples and stores the output state of each dimmer, and when the leakage detection circuit detects a leakage, an output detection circuit whose output state changes before and after the occurrence of leakage is connected. The lighting device according to claim 6, wherein it is determined that electric leakage has occurred in a series circuit of the optical device and the lighting load. 8. A lighting device in which a plurality of series circuits of a dimmer and a lighting load are connected in parallel to one AC power source, and a plurality of series circuits of the dimmer and the lighting load are connected to each other. Between the parallel circuit and the AC power supply, a leakage detection circuit that detects leakage due to an unbalanced current is provided, and an output detection circuit that detects the output voltage is provided for each dimmer. A means for selectively inputting a dimming signal that sets the dimming level and a confirmation signal that turns off the lighting load is provided, and the dimmer that supplies power to the lighting load when leakage is detected by the leakage detection circuit. Confirmation signals are sequentially input to turn off the lights temporarily, and when the leak detection circuit no longer detects the leak, the lights are turned off and it is judged that there is a leak in the series circuit of the dimmer and the lighting load. The control means for keeping the And a lighting device. 9. The lighting device according to claim 8, wherein the leakage detection circuit detects a zero-cross point of the AC power supply and inputs a confirmation signal to each dimmer at the time of detecting the zero-cross point. 10. When a leakage detection circuit detects a leakage during the period when the lighting load is turned off by the confirmation signal, the dimming signal is input to the dimmer connected in series with the lighting load when the leakage is detected. The lighting device according to claim 9, wherein the confirmation signal is input to another dimmer at the next zero cross point.