JPH023276Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a lighting device in which the brightness of a lighting lamp can be adjusted by intermittent operation of a power switch.

When trying to dim the lighting, that is, change the brightness of the lighting, the conventional methods are to switch multiple lighting lights using a changeover switch and dim the light according to the number of lights, and to change the brightness by connecting multiple lighting lights in series. For example, a method of controlling light by controlling a triac and its conduction angle by the output of a phase shift circuit is used.

However, the former method using a changeover switch has disadvantages in that it requires a plurality of lamps to be used, resulting in a large and expensive lighting device and complicated dimming. The latter method of controlling the conduction angle of a semiconductor switching element allows continuous dimming using one lamp and is inexpensive. However, on the other hand, it requires a power switch and a rotary knob for a variable resistor for phase adjustment, so it requires a special device different from a general switch box or switch panel. In addition, the variable resistor is pulled out separately from the lamp and housed in the switchbox, which requires special wiring work that is different from general lamps, which is a disadvantage in that the design of the lamp is likely to be restricted and the wiring work is troublesome. There is.

The present invention provides a dimming circuit and its switching control circuit integrated with a lighting fixture, and enables dimming by controlling the circuit only by intermittent operation of the power switch of the lighting fixture, thereby overcoming the various drawbacks of the conventional lighting equipment. It has been removed. Next, the details will be explained using the drawings.

Figure 1 is a circuit diagram showing one embodiment of the present invention, Figure 2 is a circuit diagram showing an embodiment of the present invention.
Figures a and b are examples of voltage waveforms applied to a lighting lamp. In Figure 1, 1 is an AC power source, for example 100
volt commercial frequency power supply, 2 a power switch, and 3 a lighting device, in which a lighting lamp L such as an incandescent light bulb, a dimming circuit 4, and a switching control circuit 5 are integrally formed. In the dimming circuit 4, TR ₁ is a triax (bidirectional three-terminal thyristor) which is the main semiconductor switching element, and its anode and cathode are connected in series with the lighting lamp L, and connected to the AC power supply 1 via the power switch 2. be done. R ₁ is resistance, C ₁
is a capacitor and forms an impedance circuit for voltage control. ZD ₁ and ZD ₂ are Zener diodes, and TR ₂ is a triax which is a semiconductor switching element for control.The output of the Zener diode ZD ₂ is connected to its gate, and its anode and cathode are connected to the gate and anode of the triax TR ₁ . connected between. _R2 is a resistor, _C2 is a capacitor, and DI is a diac (bidirectional two-terminal thyristor), which together form the conduction angle control circuit CC of the triac _TR1 . and capacitor C ₂
is charged every half wave of the power supply voltage according to the time constant determined by the resistor _R2 , and when the voltage reaches a predetermined voltage in the positive and negative half waves, the diac DI
conduction. Therefore, by adjusting the resistance value of the resistor R ₂ , the triac TR 1 is made conductive at an arbitrary phase angle θ of the positive and negative half-waves of the power supply voltage, as shown in the voltage waveform diagram shown in Figure ₂ . Current can be passed through the lighting lamp L, and its brightness can be adjusted. Returning to FIG. 1, in the switching control circuit 5
REC is a single-phase full-wave rectifier circuit, D ₁ is a reverse current blocking diode, C ₃ is a capacitor, and R ₃ is a discharge resistor, forming a first voltage holding circuit VH ₁ . _D2 ,
D ₃ is a reverse current blocking diode, C ₄ is a capacitor,
R ₄ is a discharge resistance and is a second voltage holding circuit.
Form VH ₂ . PUT is a programmable unidirectional transistor (n-gate thyristor, hereinafter referred to as a unidirectional transistor), and a single-phase full-wave rectifier circuit REC is connected between its anode and cathode via the diodes D ₂ and D ₃ .
connected to. Furthermore, the first voltage holding circuit VH ₁ is connected between the gate and cathode via resistors R ₅ and R ₆ .
A capacitor C ₃ of the second voltage holding circuit VH ₂ is connected in parallel between the anode and the cathode via _a resistor R ₆ . During charging, the terminal voltage of capacitor C ₃ becomes, for example, about 1 volt lower than the terminal voltage of capacitor C ₄ due to diode D ₁ and resistor R ₃ , and the gate of unidirectional transistor PUT is reverse biased to Select circuit constants to maintain continuity. R ₇ is a resistor and is connected to a single-phase full-wave rectifier circuit via diode D ₂ .
It is connected in parallel to the DC output side of the REC, and together with the resistor R ₃ forms a discharge circuit for the capacitor C ₃ of the first voltage holding circuit VH ₁ . In this case, the discharge time constant of the capacitor _C3 is made to be about one order of magnitude smaller than that of the capacitor _C4 of the second voltage holding circuit _VH2 .
The values of the resistors R ₃ , R ₄ , R _{7 ,} etc. are selected so that when the capacitors C ₃ and C ₄ are discharged, the anode-gate voltage of the unidirectional transistor PUT becomes lower with respect to the anode side and a conductive state is obtained. Ru. Further, when the power switch 2 is in the on state and the unijunction transistor PUT is in the conductive state,
The resistor R ₁ and the capacitor C ₁ are set so that the voltage applied to the series circuit of the Zener diodes ZD ₁ and ZD ₂ becomes less than the Zener voltage and no current flows. Next, the operation of this circuit will be explained.

A Turn on the lighting When power switch 2 is turned on, the capacitor
Power supply voltage is supplied to the single-phase full-wave rectifier circuit REC of the switching control circuit 5 via C ₁ and resistor R ₁ , and the resulting DC output voltage is passed through the first and second voltage holding circuits.
Charge capacitors C ₃ and C ₄ of VH ₁ and VH ₂ .
As described above, the charging voltage value of the capacitor _C3 is selected to be lower than the charging voltage value of the capacitor _C4 , and the gate of the unidirectional transistor PUT is placed in a reverse bias state. Therefore, PUT remains non-conducting.
When capacitors C ₃ and C ₄ are fully charged and no current flows, the impedance of the single-phase full-wave rectifier circuit REC equivalently viewed on the DC side becomes large.
The voltage applied to the Zener diodes ZD 1 and ZD ₂ of the dimming circuit 4 _, which had been suppressed until then by the series impedance of the resistor R ₁ and the capacitor C ₁ , becomes equal to or higher than the Zener voltage. For this reason, a current is supplied to the gate of triac TR ₂ , making TR ₂ conductive, and as a result, a current is supplied from power supply 1 to the gate of triac TR ₁ , making TR ₁ conductive. Also, at this time, a voltage corresponding to the Zener voltage generated by the Zener diodes ZD ₁ and ZD ₂ is applied to the single-phase full-wave rectifier circuit REC to prevent discharge of the capacitors C ₃ and C ₄ . Therefore, a current based on the positive and negative full waves of the power supply voltage shown in FIG. 2a flows through the illumination lamp L through the path [power supply 1 → power switch 2 → illumination lamp L → triact TR ₁ → power supply 1], and the lamp is lit.

B. Dimming of illumination lamp L Dimming is performed by turning off the power switch 2 and turning it on again within a predetermined time. That is, when the power switch 2 is turned off, the voltage supplied to the single-phase full-wave rectifier circuit REC is turned off, and the voltage that charges the capacitors C ₃ and C ₄ is also turned off. For this capacitor C ₃
The charge in capacitor C ₃ → resistor R ₃ → diode D ₂ → resistor R ₇ → capacitor C ₃ is discharged, and the charge in capacitor C ₄ is also discharged through resistor R ₄ . capacitor as mentioned above
Since the discharge time constant of C ₃ is set to be about one order of magnitude smaller than that of capacitor C ₄ , the terminal voltage of capacitor C ₃ decreases faster than that of capacitor C ₄ . Therefore, as discharge occurs, the anode-to-gate voltage with respect to the cathode of the unidirectional transistor PUT becomes lower on the gate side, and the unidirectional transistor PUT
becomes conductive due to the discharge of the charge in capacitor _C4 . At this time, the charge in the capacitor _C3 is also discharged through the PUT after it becomes conductive. And when the voltage of capacitor _C3 becomes below a certain value,
The unidirectional transistor PUT becomes non-conductive, but for example, the time from when PUT starts conducting to when it becomes non-conductive is long enough to operate power switch 2.
It is set to about 0.1 to 0.15 seconds, and the power switch 2 is turned on again during this conduction period. Then, the power supply 1 is connected again to the single-phase full-wave rectifier circuit REC of the switching control circuit 5, and voltage is supplied to the unidirectional transistor PUT via the diodes D ₂ and D ₃ , and the voltage is supplied to the unidirectional transistor PUT through the capacitor C ₁ and the resistors R ₁ and R. The current determined by ₆ continues to flow. Therefore, PUT continues to be conductive. Here, as mentioned above, the current flowing through the unidirectional transistor PUT causes the output end voltage of the series impedance formed by the capacitor C ₁ and the resistor R ₁ , that is, the voltage value applied to the Zener diodes ZD ₁ and ZD ₂ to increase Since it is set to be lower than the Zener voltage value, no current flows to the gate of triac TR ₂ , and TR ₂ becomes non-conductive. However, since the power supply 2 is applied to the series circuit of the resistor R ₂ and the capacitor C ₂ of the conduction angle control circuit CC through the illumination lamp L,
capacitor with a time constant determined by R ₂ and C ₂
C ₂ is charged every positive and negative half-wave of AC voltage, and the terminal voltage of capacitor C ₂ is activated every positive and negative half-wave.
The breakover voltage of DI is reached. Then, DI becomes conductive and current flows through the gate of triac _TR1 . For this reason, the triax TR ₁ is, for example, shown in Fig. 2b.
As shown in the figure, in the phase of the voltage determined by the resistor R ₂ and the capacitor C ₂ , conduction occurs for each positive and negative half wave, and current flows only in the shaded area in the figure.
The brightness of the illumination lamp L is lowered from when the power switch 2 is first turned on.

C Return to the normal brightness of the lighting Turn off the power switch 2 and turn off the conduction angle control circuit.
Stop supplying voltage to CC and tryout
After TR ₁ is made non-conductive, the power switch 2 is turned on again and the illumination lamp L is lit by the operation A described above.

Therefore, according to the present invention, one lighting lamp can be dimmed only by turning off and on the power switch 2 within a predetermined time set in the switching control circuit 5. As a result, unlike the case where a plurality of illumination lights are provided and switched, the illumination device does not become large or the wiring becomes complicated. In addition, there is no need to pull out the variable resistor from the lamp and house it in the switch box together with the power switch, unlike in devices that dim the light using a semiconductor switching element and a phase shift circuit that can adjust the amount of phase shift using a variable resistor. Therefore, there is no need for special switchboxes or panels different from general ones, or special wiring.

Although the present invention has been described above with respect to a circuit using semiconductor switching elements, the circuit can be simplified by using a mechanical relay as shown in the circuit diagram shown in FIG. However, in this case, troubles are likely to occur with the contacts of the mechanical relay, so that the lifespan and operational reliability are likely to be lowered compared to semiconductor switching elements. Next, the circuit shown in FIG. 3 will be briefly explained.

Relay RY is activated before power switch 2 is turned on.
is inactive and its contact ry is in the on state. When power switch 2 is turned on, capacitor _C5 is charged via diode _D4 and resistor _R8 , and capacitor _C6 is charged via diode _D5 and resistor _R9 to the same voltage as capacitor _C5 .
Therefore, the voltage across relay RY becomes the same potential, so it does not operate, contact ry continues to be on, and current flows from power supply 1 to the gate of first triax TR ₁ via limiting resistor R ₁₁ . , it turns on and lights up near the zero phase of the power supply voltage in FIG. 2a.
Next, when power switch 2 is turned off, the capacitor
Since the supply of power supply voltage is stopped to C ₅ and C ₆ ,
The charge on capacitor _C5 is discharged through resistor _R10 , and the charge on capacitor _C6 is discharged through relay RY and resistor _R10 . Here capacitor C ₅
On the other hand, the discharge time constant of capacitor C ₆ is many times longer, so the potential on the C ₅ side lowers faster than on the C ₆ side. Therefore, the relay RY operates with a potential difference between its winding terminals, turning off the contact ry. Therefore, when the power switch 2 is turned on again while the relay RY is operating due to the discharge of the capacitor _C6 ,
For relay RY [Diode D ₅ → Resistor R ₉ → Relay
Current flows through the path RY → resistor R ₁₀ → diode D ₆ ], and the OFF operation of contact ry is maintained. Therefore, when the power switch 2 is turned off, the supply of gate current to the triac TR ₁ via the resistor _R11 is stopped, but instead of this, the conduction angle control circuit described above with reference to the circuit diagram of FIG. Triac TR ₁ is turned on in the phase determined by the set value of CC. As a result, for example, as shown in FIG. 2b, current flows through the illuminating lamp L only in the shaded portion of the voltage waveform, allowing dimming to be performed by lowering the brightness.

Although the present invention has been described above with regard to the case of dimming in two stages, it is also possible to perform dimming in any number of stages by using two or more sets of switching control circuits.

As is clear from the above description, according to the present invention, there is no need to use multiple lamps and changeover switches, or to provide a phase adjustment element of a dimmer circuit in a switch box, and it is possible to control the on/off of a power switch. It is possible to provide a lighting device that can be easily dimmed using a chisel, and its practical effects are great.

[Brief explanation of drawings]

Figure 1 is a circuit diagram showing one embodiment of the present invention;
Figures a and b are supply voltage waveform diagrams of the illumination lamp, and Figure 3 is a circuit diagram showing another embodiment of the present invention. 1... AC power supply, 2... Power switch, 3...
Illumination device, 4... Dimming circuit, 5... Switching control circuit, L... Lighting lamp, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ R ₆ ,
R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ ...Resistance, C ₁ , C ₂ , C ₃ ,
C ₄ , C ₅ , C ₆ ... Capacitor, D ₁ , D ₂ , D ₃ , D ₄ ,
D ₅ , D ₆ ... Diode, REC ... Rectifier circuit,
ZD ₁ , ZD ₂ ... Zener diode, TR ₁ , TR ₂
...TRIATSUKU, DI...DIATSUKU, VH ₁ ,
VH ₂ ... Voltage holding circuit, CC... Continuity angle control circuit,
RY...Relay, ry...Contact.

Claims (1)

[Scope of utility model registration request] A lighting lamp connected to an AC power source via a power switch, a main semiconductor switching element connected in series with the lighting lamp, and a capacitor of a phase circuit consisting of a resistor and a capacitor connected to the AC power source via the power switch and lighting lamp. A dimming circuit having a conduction angle control circuit made of a semiconductor switching element that conducts at a set phase by voltage to turn on the main semiconductor switching element, and is charged by the rectified voltage of the AC power supply via the power switch and turns off the power switch. The control current supply circuit that turns on the main semiconductor switching element is turned on based on the relative relationship between the first and second capacitors, each having a charging circuit and a discharging circuit, and their charging potentials, and this is turned on when the power switch is turned off. A switching control device comprising a switching element that shuts off the conduction angle control circuit based on the relative relationship between the discharge potentials of the capacitor and maintains this cutoff state by turning the power switch on again before the discharge is completed. Lighting device with circuit.