JPH11233283A - Lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce standby power by preventing intermittent start-up of a chopper control part. SOLUTION: In this lighting system, an AC power source 1 is connected to a lamp (fluorescent lamp) 5 through a rectifier 2, a chopper 3 and an inverter 4, and the chopper 3 is controlled by a chopper control part (composed of ICs) 7 including a starting circuit 6 composed of a resistor R and a capacitor C that is connected from the rectifier 2 (or another rectifier connected to the AC power source 1). When the power from a DC power source 8 is not supplied to the chopper control part 7, the starting circuit 6 is not operational.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device in which an AC power supply is connected to a lamp via a rectifier, a chopper and an inverter.

[0002]

2. Description of the Related Art An AC power supply is connected to a lamp via a rectifier, a chopper and an inverter, and the chopper is controlled by a chopper controller having a starting circuit connected from the rectifier or another rectifier connected to the AC power supply. In the lighting device, the chopper control unit repeats the intermittent start by the start circuit in a state where DC power is not supplied to the chopper control unit, and the power switching element in the chopper switches due to the intermittent start, thereby causing a switching loss. It has occurred.

[0003]

Although the switching loss and the like correspond to standby power, it has not been noticed as a problem to be solved in the past.
SUMMARY OF THE INVENTION In view of the problems to be solved, an object of the present invention is to prevent intermittent activation of a chopper control unit and reduce standby power.

[0004]

Means for solving the problems are as described in the claims.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described. However, this is merely an exemplary embodiment adopted based on the present invention, and the present invention will be described based on matters unique to the embodiment. Therefore, the technical scope of the present invention should be determined based on the matters stated in the claims and matters substantially equivalent to the matters.

In the illustrated embodiment, an AC power supply 1 is connected to a rectifier 2
And a lamp (fluorescent lamp) 5 via a chopper 3 and an inverter 4. The chopper 3 is connected to the rectifier 2.
(Or another rectifier connected to the AC power supply 1), a starting circuit 6 composed of a resistor R and a capacitor C connected thereto.
A lighting device controlled by a chopper control unit (comprising an IC) 7 having a DC power supply 8 not supplied to the chopper control unit 7. is there. Note that a smoothing capacitor 9 is provided on the output side of the chopper 3.

A control means 10 composed of a microcomputer or the like controls the lighting device. The control means 10 receives an infrared remote control signal or a signal from a sensor 11 for sensing infrared rays generated from the human body. Numeral 10 controls the lighting state of the lamp 5 and the bean ball 12. Control means 1
0 is supplied with a DC voltage of +5 V by a DC power supply 8 in which the output DC voltage of the chopper 3 is lowered.
Also has a DC voltage output of + 12V, which is
Inverter control unit (comprising an IC) 1 interposed for controlling inverter 4 with an output signal of control means 10
3 and the chopper controller 7.

When the sensor 11 senses a light-off command signal for the lamp 5 emitted from a transmitter or the like (not shown), a light-off control signal is input from the control means 10 to the inverter 4 via the inverter control unit 13 and the lamp 5 is turned off. I do. The control means 10 controls the DC power supply 8
For example, switch means 14 is opened so as not to be supplied to 3 and chopper control unit 7. As a result, generation of standby power of the inverter control unit 13 is prevented.

When the switch means 14 is opened, continuous oscillation of the chopper control unit 7 is stopped. However, as it is, as described above, the chopper control unit 7 repeats intermittent starting by the starting circuit 6, and intermittently starts. Upon activation, a power switching element (not shown) in the chopper 3 switches, causing a switching loss. In order to prevent this power consumption, transistors 15 and 1
6 and an invalid control circuit for the starter circuit 6 using an attached resistor or the like. Note that the diode 17 is for backflow prevention.

When the switch means 14 is closed, the transistor 15 is on and the transistor 16 is off, so that the DC power supply 8 is applied to the chopper control unit 7. When the switch means 14 is opened as described above, the transistor 15 is turned off and the transistor 16 is turned on.
Since the voltage generated in the capacitor C in the starting circuit 6 becomes extremely small and the starting circuit 6 becomes invalid and the chopper control unit 7 does not start intermittently, the power switching element (not shown) in the chopper 3 switches by the intermittent starting and the switching is performed. Loss can be prevented from occurring.

More specifically, a general-purpose IC, for example, MC33262 manufactured by Motorola is suitably used for the chopper control unit 7. However, the voltage required for starting oscillation, that is, for starting, requires at least about + 15V. , The voltage necessary for activating the chopper control unit 7 is obtained by the activating circuit 6, but when the switch means 14 is open, the base current flows into the transistor 16 via the base resistor R1 by the charging voltage of the capacitor C. Since the transistor 16 is turned on, the voltage across the capacitor C is kept extremely low, and the voltage required for starting is not applied to the chopper control unit 7, so that the chopper control unit 7 does not start even intermittently. It is.

The miniature ball 12 and the switch element 19 are connected in series from the AC power supply 1 via a rectifier 18 different from the rectifier 2. In a state where the bead ball 12 is controlled to be turned on with the switch element 19 closed by a control signal from the control means 10, the lamp 5, which is the main illumination, is controlled to be turned off by the control means 10. Bean ball 1
The activation circuit 6 is invalidated to prevent wasteful power consumption, as in the case where both 2 are turned off.

The lighting device is connected to the AC power supply 1 via a wall switch 20 in the room, and is connected to the wall switch 2.
When the lighting device has a function of changing the lighting state by performing a shut-off operation within a predetermined time (for example, within 1 to 2 seconds) with respect to 0 (it is known that the function can be easily implemented by a program of the control means 10). , The bean ball 12 lights up and the lamp 5
Is controlled to turn off the light, the activation circuit 6 is invalidated to prevent wasteful power consumption. That is,
An example in which the present invention is applied to a lighting device without the sensor 11 is shown. Whether or not the power cutoff operation by the wall switch 20 is within a predetermined time is determined by controlling the output signal of the power cutoff detecting means 21 connected from the rectifier 18 via a voltage-dividing resistor as appropriate to the control set by the above-described program. The determination can be made by inputting to the means 10.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 AC power supply 2 Rectifier 3 Chopper 4 Inverter 5 Lamp 6 Start circuit 7 Chopper control part 8 DC power supply

Claims (1)

[Claims] An AC power supply is connected to a lamp via a rectifier, a chopper and an inverter, and the chopper is controlled by a chopper control unit having a starting circuit connected from the rectifier or another rectifier connected to the AC power supply. A lighting device, wherein the starting circuit is disabled in a state where DC power is not supplied to the chopper control unit.