JPS6214636Y2 - - Google Patents

Description

[Detailed description of the invention] This invention uses two of the three-wire transmission lines to supply power, and the remaining one line transmits the dimming control level to control the dimming of the lighting load. The present invention relates to a dimming control system.

FIG. 1 shows a conventional dimming control system. 3 is a dimming control device that controls dimming of the lighting load 10, and its power input terminals 4 ₁ and 4 ₂ are connected to one ends of the first and second transmission lines 2 ₁ and 2 ₂ , respectively. The AC power source 1 is connected to the other ends of the transmission lines 2 ₁ and 2 ₂ via a relay contact 11 .
7 is a dimming control input terminal, and the dimming level of the lighting load 10 is controlled according to the voltage applied to this dimming control input terminal 7. A third transmission line ₂₃ is connected to the dimming control input terminal 7, and the other end of the third transmission line ₂₃ is connected to the other end of the first transmission line ₂₁ via an on/off switch 6. connected. A bidirectional thyristor 8 is connected in parallel to the on/off switch 6, and by controlling the phase of the conduction state of the bidirectional thyristor 8, a dimming control current is supplied to the dimming control input terminal 7. This is what I did. Reference numeral 5 denotes a fuse, which is fused to protect the thyristor 8 when an excessive current flows through the thyristor 8. By the way, in the conventional circuit shown in FIG. 1, if the first transmission line 2 ₁ and the third transmission line 2 ₃ are incorrectly connected as shown by the dashed line, it is possible to turn on/off switch 6 without noticing. If you turn it on so that all lights are on, and then turn on the power in this state, the lighting load of 10
is one that lights up completely. This is because the power input terminal ₄₁ has an on/off switch 6 and a third transmission line 2.
₃ , and the full lighting voltage is applied to the dimming control input terminal 7 via the first transmission line ₂₁ . However, in this state, when the on-off switch 6 is turned off to switch to dimming operation, the main current of the dimming control device 3 will continue to flow through the thyristor 8, and the dimming control input terminal 7 will be connected to the first transmission signal. Since the full lighting voltage is always applied through the line ₂₁ , the main current of the dimming control device 3 is at its maximum, and therefore a very excessive current flows through the thyristor 8. At this time, the fuse 5 is blown to protect the thyristor 8.
A large current flows through the thyristor 8 until it melts, causing the problem of deterioration of the thyristor 8. Also, if the capacity of the fuse 5 is selected incorrectly, it may lead to the destruction of the element. Ta.

Therefore, a dimming control system shown in FIG. 2 is provided. This connects the AC power supply 1 to the power input terminals 4 ₁ , 4 ₂ of the dimming control device 3 via the first and second transmission lines 2 ₁ , 2 ₂ , and connects the fuse 5 and the on/off switch 6 in series. The fuse 5 side of the circuit is connected to one end of the AC power supply, and the on/off switch 6 side of the series circuit is connected to the dimming control input terminal 7 of the dimming control device ₃ via the third transmission line 23. A tropic thyristor 8 is connected in parallel with the on/off switch 6.

However, in the conventional example shown in Fig. 2, if the first transmission line ₂₁ and the third transmission line ₂₃ are incorrectly connected as shown by the dashed line in the figure, the on/off switch can be turned off without noticing. When the main power source is turned on with the switch 6 closed and the main power source turned on, the main current of the dimming control device 3 will flow through the fuse 5, so the fuse 5 will be blown. At this time, since both ends of the bidirectional thyristor 8 are short-circuited by the on-off switch 6, overcurrent will not pass through the thyristor 8, and therefore the thyristor 8 will be damaged or deteriorated. It is something that never happens. However, in the conventional example shown in FIG. 2, if the fuse 5 blows, even if the incorrect connection is restored, unless the fuse 5 is replaced, all lights can be turned off by closing the on/off switch 6. In applications where it is necessary to turn on the lighting load as soon as possible and it is necessary to turn on the lighting load as soon as possible, for example, if there is no replacement fuse 5 on hand, there is a problem in that it becomes a big problem if there is a delay in replacing the fuse 5. Ta.

The present invention was developed in view of the above points, and its purpose is to minimize deterioration and damage to circuit elements when the dimming control device and transmission line are incorrectly connected. It is an object of the present invention to provide a dimming control system which is capable of lighting up a lighting load in its entirety even when a fuse is blown, if necessary.

An embodiment of the present invention will be described below. Since the overall configuration is the same as that of the circuit shown in FIG. 2, the explanation of the overlapping parts will be omitted. In this embodiment, as shown in FIGS. 3 and 4, the second
In place of the on/off switch 6 in the circuit shown in the figure, a three-contact changeover switch 34 having first to third contacts 34a to 34c is used, and the first contact 34a
Connect the fuse 5 side of the series circuit of the three-contact changeover switch 34 and the fuse 5 to one end of the AC power supply 1, and then switch the series circuit changeover switch 34
The common contact 34d side of is connected to the dimming control input terminal 7 of the dimming control device ₃ via the third transmission line 23. In addition, the second contact 34 of the changeover switch 34
b is an empty contact, and this second contact 34
By switching between the contact point b and the first contact point 34a, it performs the same function as the conventional on/off switch 6. Therefore, the changeover switch 3 which switches the bidirectional thyristor 8 to the first connection 34a side
4 is connected in parallel. In this embodiment, the third contact 34c is connected to one end of the AC power source 1.

However, in this embodiment, when turning on the power, the changeover switch 34 must be set to the first contact 34a.
If there is an incorrect connection, the fuse 5 will blow out in the same way as in the circuit shown in FIG. 2 described above. In this case, if the connection is restored to its original state and the changeover switch 34 is switched to the third contact 34c side, voltage will be applied to the third transmission line ₂₃ from the first transmission line ₂₁ . This is effective because the lighting load 10 can be fully lit, and in applications where the lighting load 10 needs to be lit as soon as possible, the time required to replace the fuse 5 can be saved. When performing dimming control using the bidirectional thyristor 8, the selector switch 34 is set to the dimming position, that is, the contacts 34a, 34c.
It is sufficient to set the contact point 34b at an intermediate position.

Other configurations will be explained below. 12 is a distribution board, and the power supply voltage of AC 200V is connected to the relay contact 11.
and the discharge lamp lighting device 1 via the transmission lines 2 ₁ , 2 ₂
This is supplied to the dimming control device 3 in 3. The dimming control device 3 includes a control section 14 and a main circuit section 15, and the main circuit section 15 includes a ballast for a discharge lamp serving as a lighting load 10. The relay contact 11 is controlled to open and close by a relay coil 16, and this relay coil 16 is connected to the distribution board 12 via a breaker 17, and is connected to a control relay contact 19 of a terminal device 18 for remote control. Therefore, energization is controlled. An inspection on/off switch 20 is connected in parallel to this control relay contact 19. The breaker 17
Power is supplied from the output side to the DC power supply circuit 22 of the dimmer unit board 21, and the output of this DC power supply circuit 22 is further supplied to the phase control circuit 9 and to the master fader of the fader board 23. 24 is also supplied. A single fader 25 is connected to the output side of the master fader 24 and supplies a DC 0V to 10V fader signal to the phase control circuit 9. This phase control circuit 9 controls the phase of the bidirectional thyristor 8 according to the output signal of the power synchronization circuit 26 and the fader signal from the fader board 23. As described above, this bidirectional thyristor 8 is connected in parallel with the changeover switch 34, and is configured to supply a dimming control signal according to the fader signal to the dimming control input terminal 7 of the dimming control device 3. ing. 27 is a remote control panel, which connects the terminal device 18 of the load switching panel 29 via a shielded wire 28.
A control signal is also transmitted to a logic section 30 of the fader board 23, and this logic section 30 can also be controlled by an individual switch 31. Reference numeral 32 denotes a distribution board, which supplies a power supply voltage of 100V AC to the DC power supply circuit 33 in the fader board 23 and the remote control board 27. The remote control panel 27 opens and closes the control relay contacts 19 of the terminal device 18 provided in the load switching panel 29 according to a preset time schedule, and determines whether the lighting load 10 is turned on or off. This is for selecting the master fader 24. Further, the single fader 25 provides a fader signal of 0V to 10V to the phase control circuit 9 to control the phase of the bidirectional thyristor 8, and the lighting load 1
0 in the range of 20% to 100%.

[Effect of idea]

As described above, the present invention connects an AC power source to the power input terminal of a dimming control device through the first and second transmission lines, and connects a three-contact changeover switch and a fuse, which are switched to the first contact side. The fuse side of the series circuit is connected to one end of an AC power supply, and the common contact side of the changeover switch of the series circuit is connected to the dimming control input terminal of the dimming control device via a third transmission line, so that bidirectional A thyristor is connected in parallel with the changeover switch that has switched to the first connection side, a phase control circuit for controlling the phase of the bidirectional thyristor in synchronization with the AC power supply is connected to the bidirectional thyristor, and the first side of the changeover switch is Since the second contact is an empty terminal and the third contact is connected to one end of the AC power supply, it is possible for example to connect the first transmission line and the third transmission line incorrectly and turn off the changeover switch without realizing it. When switching to the first contact side for full lighting, the main current of the dimming control device will flow through the fuse, so this fuse will melt, and at this time, both ends of the bidirectional thyristor will be connected to the changeover switch. Since the thyristor is short-circuited by the Since the contact is connected to one end of the AC power supply, even if the fuse blows due to incorrect connection between the dimming control device and the transmission line, after the incorrect connection is restored, the changeover switch can be connected to the third contact. By switching to the side, you can connect the AC power source to the dimming control input of the dimming control device and bring the lighting load to full lighting even without a fuse.
For example, this is particularly effective in applications where it is necessary to turn on the lights as soon as possible, since the time required to replace the fuse can be saved.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a conventional dimming control system, Figure 2 is a circuit diagram of another conventional dimming control system, Figure 3 is a circuit diagram of an embodiment of the present invention, and Figure 4 is the same as above. It is a main part circuit diagram. 1 is an AC power supply, 2 ₁ to 2 ₃ are transmission lines, 3 is a dimming control device, 4 ₁ , 4 ₂ are power input terminals, 5 is a fuse, 7 is a dimming control input terminal, 8 is a bidirectional thyristor, 9 is a phase control circuit, 34 is a changeover switch, 34a is a first contact, 34b is a second contact,
34c is a third contact, and 34d is a common contact.

Claims (1)

[Scope of utility model registration request] An AC power source is connected to the power input terminal of the dimming control device via the first and second transmission lines, and the fuse side of the series circuit of the fuse and the three-contact changeover switch switched to the first contact side is connected to the AC power source. The common contact side of the changeover switch of the series circuit is connected to the dimming control input terminal of the dimming control device via a third transmission line, and the bidirectional thyristor is connected to the dimming control input terminal of the dimming control device.
A phase control circuit that controls the phase of the bidirectional thyristor in synchronization with the AC power supply is connected in parallel with the changeover switch switched to the connection side of the bidirectional thyristor, and the second contact of the changeover switch is left open A dimming control system comprising a terminal and a third contact connected to one end of the AC power source.