JP2000106285A - Mosfet antiphase control dimmer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a MOSFET antiphase control dimmer capable of increasing the load rating of equipment by limiting a rush current. SOLUTION: An antiphase control dimmer, having a built-in MOSFET part 1 which has two MOSFETs connected in series with an AC power supply E, along opposite directions and a built-in power supply part 2 for driving the MOSFET part 1, and subjecting the AC power supply E to antiphase control by use of the MOSFET part 1 to thereby control the power supplied to load, is provided with a 0-V detection circuit 3 for detecting the zero-cross point of the AC power supply E, a current detection part 4 for detecting current flowing in the MOSFET part 1, a comparison circuit part 5 for monitoring the outputs from a current-detection part 4 and the output of the driving power supply part 2, an optically coupled semiconductor relay 6 connected to the MOSFET part 1, and a latch circuit 7 operating the optically coupled semiconductor relay 6, according to the signals from the comparison circuit part 5 and the 0-V detection circuit 3. The on width of an excess current is limited, irrespective of the on command width of the control signal, so that the current flowing in the MOSFET part 1 does not become larger than a prescribed value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-phase control dimmer for controlling light supplied to a lighting load by controlling the phase of an AC power supply.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 7, a phase control dimmer 1 that controls the phase of an AC power supply E to control the power supplied to an incandescent lamp load L to perform dimming is self-holding in a switching element. With possible thyristor elements and MOSFETs
There is a device using an arbitrarily extinguishable element such as
When the current rises, it always crosses zero and the current surge is reduced compared to a normal phase control circuit.This reduces the electromagnetic noise generated by the phase control device and performs an anti-phase control operation that is effective for the growling of the lamp. Therefore, a thyristor element that can self-extinguish only with a current of 0 cannot be used.

Therefore, a conventional phase control dimmer using a MOSFET employs an element having a capacity capable of withstanding an inrush current which becomes the largest when the ignition phase is 90 degrees. Therefore, as shown in FIG. 8, the MOSFETs Q1, Q2, etc., are used as switching elements for controlling power, are connected in series and in the reverse direction, and one is used for energizing the AC waveform in the positive direction and the other is used for the negative energizing. A phase control dimmer 1 that controls a conduction mode and a non-conduction mode by controlling a gate voltage of a switching element using a gate power supply G1 has been a conventional example.

Since the filament of an incandescent lamp has a small resistance at room temperature, an inrush current of 10 times or more the rated value of the incandescent lamp flows at the moment when the current starts to flow to the load, and this state continues until the filament is heated.

In general, MOSFETs have a lower surge current rating than thyristor elements. In addition, since it takes time from the application of the AC power supply to the output voltage of the drive power supply sufficiently rising, when the MOSFET is turned on at the gate voltage just below the threshold, the on-resistance does not become sufficiently small and the current within the rating is not reached. Even if there is, the ON loss may exceed the rating and cause destruction. for that reason,
The conventional MOSFET phase control dimmer has a disadvantage that the rated load capacity cannot be increased for the element rating.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a light control device which starts a dimmer regardless of the timing of a lighting signal. After the output voltage of the drive power supply has risen sufficiently, the MOSFET is turned on when the voltage of the AC power supply is 0 V, and it has an overcurrent detection function for the inrush current of incandescent lamps. Until the current flows through the MOSFET regardless of the ON width of the control signal,
An excellent MO that can increase the load rating of the dimmer by performing the operation of limiting the ON width so as not to exceed a predetermined value
An object of the present invention is to provide an SFET antiphase control dimmer.

[0007]

According to the first aspect of the present invention, there is provided a 0 V detection circuit for detecting a zero-cross point of an AC power supply, a current detection unit for detecting a drain current flowing through the MOSFET unit as a voltage, and a current detection unit. And a second comparator for monitoring the output of the driving power supply unit.
A comparison circuit unit comprising: a comparison circuit;
A normally-on optically-coupled semiconductor relay having an output side connected to the GS terminals of two MOSFETs of the unit, and the normally-on optically-coupled semiconductor relay according to signals of the comparison circuit unit and the 0 V detection circuit. A latch circuit to operate is added to the conventional MOSFET reverse-phase control dimmer. When the device is started, regardless of the timing of the lighting signal, after the drive power supply has risen sufficiently, the voltage of the AC power supply Is 0V, the two MOSFETs of the MOSFET section
Turns on the ET and has an overcurrent detection function for the inrush current of the incandescent lamp. The MOS is turned on regardless of the ON command width of the control signal until the filament is sufficiently heated and the current is stabilized.
The feature is that the ON width is limited so that the maximum current flowing through the FET does not exceed the rating.

According to a second aspect of the present invention, the operation of the normally-on optically coupled semiconductor relay in the dimmer according to the first aspect is realized by adding a negative output function to a power supply section having a drive power supply for a MOSFET as a switching element. , The secondary side of the photocoupler is connected to the GS terminal of the MOSFET using a normally-on junction type FET and a photocoupler. Regardless, after the drive power supply has risen sufficiently, the MOSFET is turned on when the voltage of the AC power supply is 0 V, and it has an overcurrent detection function for the inrush current of the incandescent lamp. Until the power is stabilized, the ON width is limited so that the current flowing through the MOSFET does not exceed the rated value regardless of the ON command width of the control signal.

According to a third aspect of the present invention, a normally-on relay having a contact connected between a load and a MOSFET serving as a switching element is used, and 0V at the time of startup is used.
It is turned on by a normally-on relay, and does not require comparison of the output voltage of the drive power supply.When the device is started, regardless of the timing of the lighting signal, after the drive power has risen sufficiently, the AC power MOS when voltage is 0V
It has an overcurrent detection function for turning on the FET and detecting the inrush current of the incandescent lamp. Until the filament warms sufficiently and the current stabilizes, M
It is characterized in that the ON width is limited so that the current flowing through the OSFET does not exceed the rating.

[0010]

1 and 2 show a first embodiment of the present invention, and FIGS. 3 and 4 show a second embodiment of the present invention.
Next, a third embodiment will be described in detail with reference to FIGS.

FIG. 1 is a wiring diagram of an antiphase control dimmer, an AC power supply, and an incandescent lamp load. FIG. 2 is a timing chart of the circuit operation of the above-described anti-phase control dimmer. The anti-phase control dimmer shown in FIG. 1 includes a MOSFET section 1 having one main switch MOSFET for each of positive and negative, a drive power supply section 2 for driving the MOSFET section 1, and a current transformer CA.
Current detecting unit 4 for detecting the drain current flowing through MOSFETs Q1 and Q2 as a voltage by a full-wave rectifier circuit DB and the like
A comparator CP1 as a first comparison circuit for monitoring an output from the current detection unit and a comparator CP2 as a second comparison circuit for monitoring an output from the drive power supply unit 2.
A 0 V detection circuit 3 for detecting the point of time 0 V of the output voltage of the AC power supply E; and when an overcurrent and switching element drive voltage shortage signal is issued to the comparison circuit 5, the AC power supply A latch circuit 7 for maintaining the L output until the E voltage becomes 0V, and a MOS circuit of the MOSFET unit 1 until the H signal is received from the latch circuit 7 as an input.
Short-circuit GS between FET Q1 and Q2, MOSFET
A normally-on optically coupled semiconductor relay 6 for turning off Q1 and Q2 is a main component.

When Tr1 receives the control signal, the MOSFETs Q1 and Q2 operate in reverse phase according to the AC power supply E.
Control. When the device is started, the MOSFETs Q1, Q2 of the MOSFET unit 1 are controlled by the optically coupled semiconductor relay 6 regardless of the state of the control signal or the output of the drive power supply unit 2.
2 is short-circuited between the GS and the MOSFETs Q1, Q
2 remains off. The latch circuit 7 outputs an H signal when receiving the L output from the comparison circuit unit 5, and operates to keep the output until the 0V detection circuit 3 outputs the 0V signal. Accordingly, when the voltage of the AC power supply E reaches the 0V point after the output voltage of the drive power supply section 2 has sufficiently increased, the normally-on optically coupled semiconductor relay 6 is driven by the L output from the comparison circuit section 5. The H signal is sent from the latch circuit 7 to the section, and the normally-on optically-coupled semiconductor relay 6 is turned off.
The GS of the MOSFETs Q1 and Q2 of the ET unit 1 is not short-circuited, and Tr1 operates according to a control signal.
The opposite phase control of ON / OFF of the FETs Q1 and Q2 becomes possible.

[0013] Even when the filament is applied from the time of 0V, an inrush current occurs while the filament is cold. This current is detected by the current detection unit 4 and the value is detected by the CP1 of the comparison circuit unit 5.
When the latch circuit 7 determines that the current is higher than the ratings of the MOSFETs Q1 and Q2, the latch circuit 7 turns on the normally-on optically-coupled semiconductor relay 6 with an L signal,
Shorten the GS of the FETs Q1 and Q2 to
The T unit 1 is turned off.

The supply is started again at the time of 0 V, but when the filament is not sufficiently heated and the current causes an overcurrent state again, the MOSFET is turned off.

This state is continued for several cycles irrespective of the control signal until the filament is sufficiently warmed and the current does not destroy the MOSFET.

As a result, until the filament is sufficiently warmed and the current is stabilized, the ON width is limited so that the current flowing through the MOSFET unit 1 does not exceed the rated value regardless of the ON command width of the control signal.

[Second Embodiment] FIG. 3 is a wiring diagram of an anti-phase control dimmer, an AC power supply and an incandescent lamp load.
4 is a timing chart of the circuit operation of the above-described anti-phase control dimmer.

The phase control device shown in FIG. 3 has a MOSFET section 1 having one main switch MOSFET for each of positive and negative, a drive power supply section 2 for driving the MOSFET section 1, a current transformer CA and a rectifier. A current detection unit 4 for detecting a drain current flowing through the MOSFET unit 1 as a voltage by a circuit DB unit or the like, a comparator CP1 as a first comparison circuit for monitoring an output from the current detection unit, and the drive power supply unit 2. A comparison circuit unit 5 comprising a comparator CP2, which is a second comparison circuit for monitoring the output of the AC power supply; a 0V detection circuit 3 for detecting the 0V point in time of the output voltage of the AC power supply E; Is output to the comparison circuit 5, a latch circuit 7 that maintains the L output until the output voltage of the AC power supply E reaches 0 V, A main part of a control unit 6 comprising a normally-on junction type FET operated by a signal from the latch circuit 7 and first and second photocouplers, to which a positive / negative power supply comprising a voltage doubler rectifier circuit 2a is added to the unit 2 And

At the time of starting the device, the normally-on junction type FET of the control unit 6 is connected to the second photocoupler PC2 regardless of the state of the control signal or the output voltage of the drive power supply unit 2.
Until a signal is received from the latch circuit 7, the first photocoupler PC 1 is made conductive and the MO
Short-circuit between GS of SFETs Q1 and Q2 and
The ET unit 1 is turned off.

When the latch circuit 7 receives the L output of the comparison circuit section 5, it outputs an H signal and operates to maintain the output until a 0V signal is output. Therefore, the output voltage of the drive power supply section 2 is sufficiently high. After the rise, when the output voltage of the AC power supply E reaches the 0V point, an H signal is sent from the latch circuit 7 to the primary side of the second photocoupler PC2 of the control unit 6, whereby the control unit 6 Normally-on junction type F
Since the ET is turned off, the first photocoupler PC1 of the control unit 6 is also turned off, and the MOSFET unit 1 can perform on / off reverse phase control according to a control signal.

Even when the filament is turned on at 0 V, an inrush current occurs while the filament is cold. This current is detected by the current detecting circuit 4, and the value is detected by the MOSFETs Q1 and Q2.
When the latch circuit 7 determines that the current is equal to or higher than the rated value, the L signal is output until the latch circuit 7 detects the next 0V point. Therefore, the normally-on junction type FET of the control unit 6 and the first photocoupler PC1 of the control unit 6 are turned on. MOSFE of the MOSFET section 1
The GS of TQ1 and Q2 is short-circuited to turn off the MOSFET section 1.

The supply is started again at the time of 0 V, but when the filament is not sufficiently heated and the current causes an overcurrent state again, the MOSFET is turned off.

This state is continued for several cycles irrespective of the control signal until the filament is sufficiently warmed and the current does not destroy the MOSFET.

As a result, until the filament is sufficiently warmed and the current is stabilized, the operation of limiting the ON width is performed so that the current flowing through the MOSFET does not exceed a predetermined value regardless of the ON command width of the control signal.

[Third Embodiment] FIG. 5 is a wiring diagram of an anti-phase control dimmer, an AC power supply, and an incandescent lamp load.
It is a timing chart of the circuit operation of the above-mentioned opposite phase control dimmer. The phase control device shown in FIG.
An OSFET section 1, a drive power supply section 2 for driving the MOSFET section 1, a MOSFET Q of the MOSFET section 1 by a current transformer CA, a rectifier circuit DB, and the like.
1, a current detection unit 4 for detecting a drain current flowing through Q2 as a voltage, and a C for monitoring an output from the current detection unit 4
A comparison circuit section 5 composed of P2; a 0V detection circuit 3 for detecting a point of time of 0V of the output voltage of the AC power supply E; and an output voltage of the AC power supply E of 0 V when an overcurrent signal is issued to the comparison circuit 5. The L signal is continuously output until the time point, the normally-on relay is turned on, and at other times, the latch circuit 7 for outputting the H signal and the drive coil are supplied from the same drive power supply as the MOSFET, and the latch circuit 7 H signal to PC
B-contact relay PC1 that turns off the MOSFET by short-circuiting the GS of the MOSFET until the signal is input to the primary side of the relay PC1
And the main configuration.

Here, the drive current of the normally-on relay Ry1 of the control section 6 cannot be turned off even if the photocoupler PC1 of the control section 6 is turned on unless the output voltage of the drive power supply section 2 is sufficiently increased. Is selected.

When the device is started, the normally-on relay Ry1 is set to the MO state regardless of the control signal and the state of the drive power supply unit 2.
The MOSFET is turned off to short-circuit the GS of the SFET, and when the latch circuit 7 receives the H output of the comparison
A current is applied to the drive coil of the normally-on relay Ry1 via the secondary side of C1 to turn off the relay, and the MOSFET is turned off.
Enables the on / off antiphase control according to the control signal.

However, at this time, if the output voltage of the drive power supply unit 2 does not rise sufficiently, the photocoupler PC1 of the control unit 6
However, the normally-on relay Ry1 of the control unit 6 cannot turn off the output contact because the supply current to the coil is insufficient even if the signal is turned on by the H signal from the latch circuit 7. Even when the normally-on relay Ry1 of the control unit 6 is turned off and turned on, an inrush current occurs while the filament is cold. This current is detected by the current detector 4 and the value is
The rating of the FET Q, 1Q2 or more and the CP of the comparison circuit unit 5
2, the L signal is output until the latch circuit 7 detects the next 0V point, so that the photocoupler PC1 of the control unit 6 is turned off and the normally-on relay Ry1 of the control unit 6 is connected to the MOSFET unit. 1 MOSFET Q
1, the GS of Q2 is short-circuited to turn off the MOSFET section 1.

The supply is started again from 0 V, but when the filament is not sufficiently heated and the current causes an overcurrent state again, the MOSFET is turned off.

This state is continued for several cycles irrespective of the control signal until the filament is sufficiently warmed and the current does not destroy the MOSFET.

As a result, until the filament is sufficiently warmed and the current is stabilized, the operation of limiting the ON width is performed so that the current flowing through the MOSFET does not exceed a certain value regardless of the ON command width of the control signal.

[0032]

As described above, according to the first aspect of the present invention, the normally-on optically-coupled semiconductor relay, the latch circuit, and the 0V detection circuit enable the output voltage of the switching element drive power supply regardless of the timing of the lighting signal. Is fully turned on when the AC power supply is at 0V, and the current always rises from 0A in a sine curve by the reverse phase control operation.
In addition, the ON width can be limited so that the current flowing through the MOSFET does not exceed the rating regardless of the ON command width of the control signal until the filament of the incandescent lamp sufficiently warms and the current stabilizes. Does not flow. This allows the conventional MOSF
There is an effect that a load rating larger than that of the ET phase control dimmer can be set.

According to a second aspect of the present invention, the operation of the normally-on optically-coupled semiconductor relay of the MOSFET reverse-phase control dimmer according to the first aspect is provided by adding a negative output function to the driving power supply of the switching element. , Normally-on junction type FE
Since the MOSFET is turned off by the photocoupler until the output voltage of the element driving power supply is sufficiently increased regardless of the timing of the lighting signal and realized by the T and the photocoupler, the conventional MOSFET phase control dimmer as in claim 1 There is an effect that a larger load rating can be set.

According to the third aspect of the present invention, the contact of the normally-on relay is inserted into the GS terminal of the MOSFET, and the contact of the normally-on relay is turned on when the AC power supply voltage is 0V. At this time, the drive power supply for the MOSFET is also used as the drive power supply for the normally-on relay, so that the normally-on relay cannot be turned on unless the output voltage is sufficiently increased. And 2, a load rating larger than that of the conventional MOSFET phase control dimmer can be set with a simpler configuration.

[Brief description of the drawings]

FIG. 1 is a wiring diagram of an anti-phase control dimmer, an AC power supply, and an incandescent lamp load according to a first embodiment of the present invention.

FIG. 2 is a timing chart of a circuit operation of the anti-phase control dimmer.

FIG. 3 is a wiring diagram of an antiphase control dimmer, an AC power supply, and an incandescent lamp load according to a second embodiment of the present invention.

FIG. 4 is a timing chart of a circuit operation of the anti-phase control dimmer.

FIG. 5 is a wiring diagram of an anti-phase control dimmer, an AC power supply, and an incandescent lamp load according to a third embodiment of the present invention.

FIG. 6 is a timing chart of a circuit operation of the anti-phase control dimmer.

FIG. 7 is a wiring diagram of a conventional phase control dimmer capable of performing a phase control operation, an AC power supply, and a load.

FIG. 8 is a wiring diagram of a conventional phase control dimmer capable of performing an inverse phase control operation using a MOSFET or the like as a switch element, an AC power supply, and a load.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 MOSFET part 2 Drive power supply part 30V detection circuit 4 Current detection part 5 Comparison circuit part 6 Control part 7 Latch circuit E AC power supply Q1 MOSFET Q2 MOSFET L Incandescent lamp load PC1 Photocoupler PC2 Photocoupler PRy1 Normally-on optically coupled semiconductor Relay Ry1 normally-on relay FET normally-on junction type FET CA current transformer DB rectifier circuit

Claims (3)

[Claims] A MOSFET section having two MOSFETs connected in series and in opposite directions to an AC power supply;
An anti-phase control dimmer having a drive power supply unit for driving an OSFET unit and controlling the power supplied to the incandescent lamp load by controlling the phase of the AC power supply by the MOSFET unit, 0V detection circuit for detecting the zero cross point of
A comparison circuit comprising: a current detection unit that detects a drain current flowing through an FET as a voltage; a first comparison circuit that monitors an output from the current detection unit; and a second comparison circuit that monitors an output of the drive power supply unit Unit, a normally-on optically coupled semiconductor relay having an output connected to the GS terminal of two MOSFETs of the MOSFET unit, and the normally-on optically-coupled semiconductor relay according to signals of the comparison circuit unit and the 0 V detection circuit. And a latch circuit for operating the coupled semiconductor relay. When the device is started, regardless of the timing of the control signal, after the output voltage of the drive power supply sufficiently rises to a predetermined value, the voltage of the AC power supply becomes 0V. M until you reach the point
The short circuit between the GS of the two MOSFETs in the OSFET section with a normally-on optically coupled semiconductor relay does not cause the MOSFET to be turned on. Until the above, the M signal is applied regardless of the ON command width of the control signal synchronized with the AC power supply.
A MOS characterized in that an ON width of an overcurrent is limited so that a current flowing through an OSFET section does not exceed a predetermined value.
FET anti-phase control dimmer. 2. An AC power supply includes a built-in MOSFET section having two MOSFETs connected in series and in opposite directions, and a power supply section having a power supply for driving the MOSFET section and the like. In a reverse phase control dimmer that controls the power supplied to the incandescent lamp load by controlling the phase of the power supply, a 0 V detection circuit that detects a zero cross point of the AC power supply and two MOSFETs of the MOSFET section. A current detection circuit that detects a drain current as a voltage, a comparison circuit unit including a first comparison circuit that monitors an output from the current detection unit, and a second comparison circuit that monitors an output of the drive power supply unit; The MO
A control unit including a first photocoupler having an output side connected to the GS terminals of two MOSFETs of the SFET unit, a normally-on junction type FET, and a second photocoupler;
A negative output function added to the power supply unit to drive the control unit; and a latch circuit for operating the control unit in accordance with signals from the comparison circuit unit and the 0 V detection circuit. Irrespective of the timing of the control signal, after the driving power supply has sufficiently risen to a predetermined value, the MOSFE until the voltage of the AC power supply reaches the 0V point.
The first and second photocouplers of the control section short-circuit the GS of the two MOSFETs in the T section so that they do not turn on, and the inrush current of the incandescent lamp load sufficiently heats the filament to stabilize the current. A MOSFET reverse-phase control dimmer, wherein the ON width of the overcurrent is limited so that the current flowing through the MOSFET unit does not exceed a predetermined value regardless of the ON command width of the control signal. 3. A MOSFET section having two MOSFETs connected in series and in opposite directions to an AC power supply, and
A power supply for driving the OSFET section is built in, and the M
A 0 V detection circuit for detecting a zero-crossing point of a single-phase AC power supply in an anti-phase control dimmer for controlling power supplied to an incandescent lamp load by controlling the phase of the AC power supply by an OSFET section; Two MOSFs
A current detection unit for detecting a drain current flowing through the ET as a voltage; a comparison circuit unit for monitoring an output from the current detection unit; and a GS of two MOSFETs of the MOSFET unit
A control unit comprising a normally-on relay having a terminal connected to the output side and a photocoupler, and a latch circuit for operating the control unit in accordance with the signals of the comparison circuit unit and the 0 V detection circuit, respectively. Irrespective of the timing of the control signal, after the output voltage of the drive power supply section has sufficiently risen to a predetermined value, the voltage of the AC power supply is turned on by the normally-on relay at the point of 0 V, and the inrush current of the incandescent lamp In contrast to the above, the MOS is used regardless of the ON command width of the control signal until the filament is sufficiently warmed and the current is stabilized.
MOSFE characterized in that the ON width of the overcurrent is limited so that the current flowing through the FET section does not exceed a predetermined value.
T antiphase control dimmer.