JPS6323920Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a discharge lamp dimming device that uses a semiconductor phase control circuit.In particular, a phase advance capacitor is connected in series with the discharge lamp, and a large number of devices are used, which have a high power factor when lit. The lighting circuit is rated (full light) lighting all at once,
The present invention relates to a discharge lamp dimmer that dims and lights up.

Conventional phase-controlled discharge lamp dimmers control the power supplied to the discharge lamp by making a semiconductor switching element conductive at a phase angle of 0 to 180 degrees in each half cycle of AC. Power thyristors are mainly used as switching elements. This thyristor has the characteristic that once it becomes conductive during each half cycle of alternating current, a reverse voltage is applied to the thyristor, and the thyristor does not become cut off unless the current flowing through the thyristor drops below a minute holding current determined by the characteristics of the thyristor. Therefore, the power factor of the lighting circuit consisting of the lamp and the ballast is set so that the phase always lags when the lamp is lit.

Also, adjust the dimming of the fluorescent lamp of the discharge lamp to approximately 0~
If it is necessary to achieve 100% smooth operation, a filament heating transformer is installed that heats the lamp filament at a constant voltage regardless of the degree of dimming, and a pulsed voltage is applied to the lamp. Special dimming ballasts are used.

On the other hand, in order to downsize the dimmer, a high power factor type ballast with a capacitor connected in series with the lamp is also used, but the power factor needs to be lagged, and the excitation current of the ballast must be made extremely large, making the ballast large. Furthermore, since a filament heating transformer is housed in these dimming ballasts, it is necessary to wire the ballasts with three wires.

Recently, as an energy-saving measure, there has been an increasing demand for using general ballasts to dim the brightness to 60 to 70%, and to turn on the full light when there are many customers or when the luminous flux of the lamp decreases. .
For applications that require such requirements (stores such as department stores and supermarkets, factories, and offices), serial sequential start type ballasts, which light two fluorescent lamps with one ballast, are often used. has been done. This ballast has a high power factor with almost no delay even if the power factor is leading or lagging when lighting the lamp. For this reason, when attempting to dim a lighting circuit consisting of a ballast and a lamp in a phase-controlled manner, there was a drawback that flickering occurred near full brightness or dimming became impossible.

FIG. 1 is a wiring diagram of a generally widely used series sequential start type ballast and a lamp. In this figure, 1 is a commercial AC power supply, 2 is a series sequential start type ballast, and 3 and 4 are lamps. FIG. 2 is a diagram showing the input voltage of the ballast 2 and the waveform and phase relationship of the input current, where a is the input voltage and b is the input current. In the circuit configuration shown in Figure 1, as can be seen from the waveform diagram in Figure 2, the input current b is slightly delayed in phase from the input voltage a. If a lamp with lower voltage and increased lamp current is used, the phase of the input current may lead the input voltage, and if a dimmer is connected in this way, dimming will no longer be possible.

This invention eliminates these conventional drawbacks and enables full-light lighting with 100% brightness even when the lighting circuit consisting of a lamp and ballast has a high power factor with a leading phase or a slow phase with little lag. , provides a discharge lamp dimming device that can control lighting at a dimming rate of 60 to 70%.

In particular, this idea suggests that even if the power factor is a slow phase with little lead or lag when all lights are on, when the brightness is set to 60 to 70% using a phase control type dimmer, the power factor will lag considerably. This method was developed by focusing on the fact that even if the lamp current decreases, the input current of the lighting circuit does not decrease, but rather increases, and has the feature of achieving even greater power savings.

The details of this invention will be explained below according to the illustrated embodiments. Figure 3 uses the lighting circuit shown in Figure 1 above, and even if this lighting circuit advances, it can control dimming of 60 to 70% or full brightness. 1 is a connection diagram of a device showing an embodiment of the invention; FIG.

In FIG. 3, 1 is a commercial AC power supply, 2 is a series sequential start type ballast, and 3 and 4 are fluorescent lamps.
Reference numeral 5 designates a thyristor as a semiconductor switching element for power control, and this thyristor 5 constitutes a phase-controlled dimming circuit. One end of this thyristor 5 is connected to one end of the commercial AC power supply 1. The other end is the thyristor 6 of the load phase adjustment circuit composed of the thyristor 6 and the chiyoke coil 8.
It is connected to one end of the series sequential start type ballast via one end and one pole of the branch no fuse breaker 9. The other end of the thyristor 6 is connected to one end of the chiyoke coil 6, and the other end of the chiyoke coil 6 is connected to the other end of the series sequential start type ballast via the other end of the commercial AC power supply 1 and the other pole of the branch no fuse breaker 9. connected to one end. A gate signal generating circuit 7 sends a phase control signal to the thyristors 5 and 6, and is connected to the third electrode (gate) of the thyristors 5 and 6. 10 is a changeover switch for switching between full-light lighting and dimming lighting.

FIG. 4 is a circuit diagram showing one embodiment of this gate signal generating circuit.

In FIG. 4, 11 is a zener diode 13
12 is a diode bridge for rectifying alternating current, 14 and 1
5 is a resistor for dividing the voltage of the Zener diode 13, 16 is a diode for preventing backflow, 1
7 is an electrolytic capacitor for smoothing the trapezoidal pulsating current clipped by the Zener diode 13 to direct current; 18 is a resistor for limiting the current flowing to the transistor 19; 20 is the transistor 2;
A resistor 22 limits the current flowing to the collector of the transistor 21. A resistor 22 limits the current flowing to the collector of the transistor 21. The transistors 19 and 21 constitute a signal inversion circuit, which generates a signal synchronized with the commercial AC power supply. 23 is a resistor, and 24 is a capacitor, which are connected in series to form a time constant circuit.

25 is a unidirectional transistor developed for ignition of thyristors, 26 is a base resistor, and 27 is a pulse transformer. Further, 28 is a transistor, 29 is a resistor for limiting the collector current, 30 is a resistor, and 31 is a capacitor, which are connected in series to form a time constant circuit. 32 is a unijunction transistor,
33 is a resistor, and 34 is a pulse transformer. 3
5 and 36 are diodes for backflow prevention;
37 is a transistor, and 38 and 39 are resistors. Resistors 38 and 39 are connected in series to supply the divided voltage to the emitters of unijunction transistors 25 and 32 via diodes 35 and 36, respectively. 40 is a resistor, which controls the switch 10 for dimming lighting and full lighting.
This is to limit the base current of the transistor 37 when turned on. Each of the above elements is connected as shown in the figure.

The operation will be explained with reference to FIGS. 3 and 4.

When the commercial AC power supply 1 is applied with the dimming lighting/full lighting switching switch 10 in the ON state, this voltage is applied to the gate signal generation circuit 7 and the thyristor 5. The voltage applied to the gate signal generation circuit 7 is stepped down by a resistor 11 and then passed through a diode bridge 1.
2, the current is rectified, converted into a pulsating current, and applied to both ends of the Zener diode 13. The voltage is then clipped by the zener diode 13, resulting in a trapezoidal waveform voltage. This voltage is applied to the dividing resistors 14 and 15,
From that connection point, the synchronization signal is transmitted to transistor 1.
9 is supplied to the base. Then, by inverting the signal with this transistor 19 and applying this signal to the transistors 21 and 28, the electric charge of the pulse generation capacitors 24 and 31 is discharged at the point where the voltage of the trapezoidal waveform becomes almost zero. It is synchronized with power supply 1. Further, the trapezoidal waveform voltage is applied to the electrolytic capacitor 1 via the diode 16.
7, where it is smoothed to become a perfect direct current. This DC voltage is applied to the resistor 18 and transistor 19.
, a time constant circuit consisting of a resistor 23 and a capacitor 24, a resistor 30 and a capacitor 31, and a series circuit consisting of a transistor 37 and resistors 38 and 39. Also, this DC voltage has a resistor of 40,
Since the voltage is also applied to the base of the transistor 37 through the switch 10, the transistor 37 becomes conductive.

On the other hand, depending on the DC voltage, the capacitors 24 and 3
1 is resistor 23, 30 and diode 35, 36
It is gradually charged through the battery, and its voltage increases. When this voltage exceeds a certain voltage determined by the characteristics of the unidirectional transistors 25, 32, the unidirectional transistors 25, 32 become conductive, and the charges in the capacitors 24, 31 are transferred through the primary windings of the pulse transformers 27, 34. is discharged, generating a pulse on its secondary side. Since this pulse is applied to the thyristors 5 and 6, the thyristors 5 and 6 become conductive. zener diode 1
At the point where the voltage clipped by 3 becomes almost zero, the transistor 19 is turned off and the transistors 21 and 28 are turned on, so that the charges in the capacitors 24 and 31 are discharged through the resistors 22 and 29. Therefore, synchronization with the commercial AC power supply 1 can be achieved. When the dimming lighting and full lighting switching switch 10 is turned on, the thyristor 5
The phase of the pulse applied to the thyristor 6 is determined according to the power factor of the entire light state of the lighting circuit, and the phase of the pulse of the thyristor 6 is delayed by 90 degrees because the load is only the chiyoke coil.

Next, the dimming lighting and full lighting switching switch 10 is activated.
The case where it is turned off is described below.

In this case, since the transistor 37 is in the off state, the capacitors 24 and 3 of the time constant circuit
1 is charged only through the resistors 23 and 30, respectively, and the phase in which the pulse is generated is inevitably delayed compared to when the changeover switch 10 is turned on. In the dimmed lighting state, the phase of the pulse generated on the secondary side of the pulse transformer 27 is set to lead the phase of the pulse transformer 34. That is, in the dimming state, thyristor 5 becomes conductive first, and thyristor 6 becomes conductive at a slightly delayed phase.

FIG. 5 is an operation waveform diagram of each part during rated (full light) lighting and FIG. 6 is a dimming lighting.

is a commercial AC power supply, and is a gate signal generation circuit 7
is the voltage of the zener diode 13, is the voltage of the synchronizing transistor 19, is the pulse voltage of the pulse transformer 27, is the pulse voltage of the pulse transformer 34, is the output voltage of the thyristor 5 and is the voltage applied to the lighting circuit, is the voltage of the thyristor 5 The current flowing through the
is the current flowing through the thyristor 6.

In this invention, a load adjustment circuit consisting of a thyristor 6 and a chiyoke coil 8 is connected between a dimming circuit consisting of a thyristor 5 and a branch circuit no-fuse breaker for the following reasons. .

In full-light lighting, a load adjustment circuit is added because the power factor of the lighting circuit needs to be delayed, but if this is connected between the no-fuse for the branch circuit and the lighting circuit, the power factor of the lighting circuit must be delayed, but if this is connected between the branch circuit no fuse and the lighting circuit, the The current in the circuit no-fuse breaker increases, causing the branch circuit no-fuse breaker to operate. In addition, when installing such a dimmer in a location that has already been installed, the phase adjustment circuit must be installed after the branch circuit no-fuse breaker, since the branch circuit no-fuse breaker is already built into the distribution board. This is difficult in terms of space and construction. In addition, in the dimmed lighting state, the lamp current decreases and the current of the capacitor connected in series with the lamp also decreases, so the apparent power factor becomes delayed, but the input of the lighting circuit at a brightness of 60 to 70% The current will be higher than in the full light-on state.
If the current of the phase adjustment circuit is added to the slow phase current of this lighting circuit, the current of the branch circuit no fuse breaker will further increase, and there is a risk that the branch circuit no fuse breaker will operate, so this current should be reduced as much as possible. is desirable.

Furthermore, the number of phase adjustment circuits also increases.

In this way, this device connects a discharge lamp and a series phase-advancing capacitor, and allows dimming even when the lamp is fully lit and the power factor is either leading or lagging, with almost no lag. By adding a phase adjustment circuit, power loss in dimmed lighting conditions is reduced and power consumption is further reduced.

In the above embodiments, a fluorescent lamp was used as the discharge lamp, but the present invention is not limited to a fluorescent lamp, and other discharge lamps may be used. Further, although the ballast is of a series sequential starting type, it is not limited to this.

Furthermore, although a switch is provided for switching between full-light lighting and dimmed lighting, the present invention is not limited to stepwise dimming, and the same effect can be obtained even with continuous dimming.

As mentioned above, this idea connects a load phase adjustment circuit consisting of a series circuit of a chiyoke coil and a thyristor to the output side of a phase control type dimmer circuit, controls the phase of the current flowing into the chiyoke coil, and controls the power factor as seen from the power supply. Since the lamp is set to have a lagging phase, even if the power factor when lighting the lamp is leading or lagging, the lighting circuit with almost no phase difference can be dimmed and lit by phase control.

[Brief explanation of the drawing]

Figure 1 is a connection diagram of a ballast that is generally called a series sequential start type ballast and a lamp, Figure 2 is a diagram showing the waveform and phase relationship of the input voltage and input current of this ballast, and Figure 3 is a diagram showing the waveform and phase relationship of the input voltage and input current of this ballast. A connection diagram showing an embodiment of this invention, Fig. 4 is a connection diagram showing an embodiment of a gate signal generation circuit, Fig. 5 is an operation waveform of each part in a full-light lighting state, and Fig. 6 is a connection diagram of each part in a dimmed lighting state. This is the operating waveform. In the figure, 1... Commercial AC power supply, 2... Series progressive type fluorescent lamp ballast, 3, 4... Fluorescent lamp,
5... Thyristor for dimming circuit, 6... Thyristor for phase adjustment circuit, 7... Gate signal generation circuit, 8
. . . Chiyoke coil, 9 . . . No fuse breaker for branch circuit, 10 .

Claims (1)

[Claims for Utility Model Registration] (1) A lamp and ballast in which a phase advance capacitor is connected in series with a discharge lamp, and there is almost no phase difference even if the power factor is leading or lagging when the lamp is lit. A lighting circuit consisting of a no-fuse breaker for a branch circuit in which many of these lighting circuits are connected in parallel,
The power supply side of the no-fuse breaker for the branch circuit consists of a chiyoke coil that is set so that the power factor as seen from the power supply is delayed when all the above lamps are turned on, and a thyristor that is connected in series with this chiyoke coil to control the chiyoke coil. a load phase adjustment circuit connected in parallel to the load phase adjustment circuit; a phase-controlled dimming circuit having a thyristor that controls the load phase adjustment circuit and the lighting circuit and connected in series between the power source and the load phase adjustment circuit; A discharge lamp dimmer comprising a phase adjustment circuit, a gate signal generation circuit for transmitting a control signal to a thyristor of the phase control type dimmer circuit, and a changeover switch for switching between full-light lighting and dimmed lighting. (2) When the selector switch is set to the full-light ON side, the thyristor of the load phase adjustment circuit and phase control type dimmer circuit conducts 180 degrees, and the power factor as seen from the power supply side is configured so that it is delayed in phase. A discharge lamp dimmer device according to claim 1, characterized in that it is a utility model. (3) Registration of a utility model characterized in that the thyristor firing phase of the load phase adjustment circuit is configured to lag behind the thyristor firing phase of the phase control type dimmer circuit when the changeover switch is set to the dimming lighting side. A discharge lamp dimming device according to claim 1 or 2.