JPS6330749B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a discharge lamp lighting device that takes measures to prevent noise.

(Prior Art) Generally, it is known that a lighting device using a discharge lamp as a light source generates high frequency noise when turning on and off every half cycle of the power supply. In particular, in recent years, a high-frequency generator using a high-frequency inverter has been used in the ballast, which is a lighting device, to light the discharge lamp at high frequency, thereby reducing the size and weight of the entire device and reducing loss. ing.

(Problems to be Solved by the Invention) When high-frequency lighting is used in this way, high-frequency noise is generated from the discharge lamp and the inverter, and noise disturbance becomes noticeable. For this reason, it has been considered to add a noise prevention circuit such as a balun transformer (balanced transformer) or a capacitor to remove high frequency noise.
However, like in general household lighting equipment, the power switch such as a pull switch is compactly stored in a case together with a high frequency generator and a noise prevention circuit, and the power switch is placed at the bottom of the case for operational and structural reasons. If the power switch is placed in a A lot of high frequency noise is generated through the stray capacitance and is fed back to the power supply. Therefore, there is a problem in that the effect of the noise prevention circuit described above is reduced by half.

The present invention was made in view of the above problems, and
An object of the present invention is to provide a discharge lamp lighting device that can effectively reduce high frequency noise in a case that houses a noise reduction device such as a high frequency generator, a power switch, and a balun transformer.

[Structure of the invention]

(Means for Solving the Problems) The discharge lamp lighting device of the present invention includes a case including a connecting line connected to a power source from one end, and a case housed in an intermediate portion of the case and supplied with power from the power source. a high-frequency generator for lighting a discharge lamp; a power switch for controlling input to the high-frequency generator on and off; an operating section is provided on the other end of the case so as to be operable from outside the case; A noise reduction device is provided between the power switches and provided within the case on one end side of the power switches.

(Function) The present invention is advantageous in terms of operation and layout, in that the power switch is provided at the other end opposite to the one end where the connection line to the power supply is introduced, and the noise reduction device is installed. Since it is interposed between the power supply and the power switch and is provided at one end where the connection line is introduced from the power switch, even if high frequency noise occurs in the power switch or the connection line to the power switch,
The transmission of this high frequency noise to the power supply side can be effectively reduced by the noise reduction device. Since the connection line to the noise reduction device has a small proportion of proximity to the high frequency generator, the problem of high frequency noise due to this connection line is small.

(Example) An example of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, 11 is a noise reduction device, such as a balun transformer, and its input side is connected to a commercial AC power source 13 via an input terminal 12 such as a plug. 14 is a power switch, for example, a household pull switch is used. This power switch 14
is a common contact 14c connected to the output side of the noise reduction device 11, and a common contact 14c connected to the output side of the noise reduction device 11, and a
Terminals 14-1, 14-2, 14 that connect and separate from c in sequence
-3. Here, the terminal 14-1 is connected to a high frequency generator 15, which will be described later, and the terminal 14-1 is connected to a high frequency generator 15, which will be described later.
2 is connected to the miniature light bulb 16 for night light, and the terminal 14-
3 is used for off-position.

In this embodiment, the high frequency generator 15 has a rectifier 18 on the input end side, and once converts AC power supplied via a power switch 14 such as a pull switch into DC power. Further, on the output end side, a high frequency converter 19 consisting of a well-known inverter or the like is provided to inversely convert the DC power to high frequency power of about 20 KHz to 50 KHz. Reference numeral 21 denotes a discharge lamp consisting of a fluorescent lamp, which is lit at high frequency using high frequency power outputted from the high frequency generator 15.

FIG. 2 shows a configuration example in which the circuit shown in FIG. 1 is assembled into an actual lighting fixture, which will be described below. Components corresponding to the circuit components shown in FIG. 1 will be described with the same reference numerals. In Figure 2,
23 is a main body cover of the lamp, and a discharge lamp 21 and a miniature light bulb 16 are attached inside the cover. Reference numeral 24 denotes a fixture cover for the lamp as a case, which is similar to the main body cover 2 above.
3. That is, in this embodiment, the case consists of the instrument cover 24 and a part of the main body cover 23. 25 is a printed circuit board,
The noise reduction device 11, the high frequency generator 15, etc. are mounted on the upper surface of the device, and the device is attached to the middle part of the instrument cover 24 as the case. In addition, a connection wire 27 connected to the AC power source 13 is introduced from one end of the case, that is, the upper part of the instrument cover 24 in this embodiment, and a power supply is introduced into the lower part of the instrument cover 24 at the other end of the case, that is, in this embodiment. A switch 14 is provided, and a hanging cord for operation is suspended through the main body cover 23 as shown in the figure. Therefore, the power switch 14 can be easily operated, and no load is applied to the printed circuit board 25 even when the hanging cord is pulled. Furthermore, power switch 1
4 can be easily placed in the center of the lighting fixture,
The shaking of the lighting equipment can be reduced when operating the hanging cord.
These devices are connected by connecting wires 27 to form the circuit shown in FIG.

In the above configuration, when the discharge lamp 21 is turned on, the power switch 14 is operated by the hanging cord to bring the common contact 14c into contact with the terminal 14-1. Through this operation, AC power is supplied to the high frequency generator 15. For this reason, the high frequency generator 15 generates high frequency power using the rectifier 18 and the high frequency converter 19, supplies it to the discharge lamp 21, and lights it at high frequency.

When the discharge lamp 21 is lit at a high frequency in this way, the high frequency noise generated in the discharge lamp 21 and the high frequency converter 19 is caused by the direct feedback loop to the power supply via the circuit line and the stray static electricity between each component. This attempts to induce high-frequency noise in the power supply via an indirect feedback loop such as capacitance, thereby causing a noise disturbance. In particular, since the power switch 14 and the connection line 27 to the power switch 14 are located close to the high-frequency generator 15 or along the high-frequency generator 15, the power switch 14 and the connection line 27 induce a lot of high-frequency noise. , and tries to return to the power supply. However, in this embodiment, for these direct and indirect feedback loops, the noise reduction device 11 is interposed at the end of the entire device including the power switch 14 when viewed from the noise source, so that the high frequency of the feedback circuit is Impedance can be increased. As a result, the amount of noise feedback can be reduced and noise interference can be eliminated. That is, conventionally, the power switch 14 was provided immediately after the input terminal 12 due to the circuit configuration.
Even if a noise prevention circuit is provided after that, the noise caused by the direct feedback loop can be removed, but in the case where the power switch 14 is arranged as shown in FIG.
It was impossible to eliminate noise indirectly induced by stray capacitance. In contrast, in this embodiment, the noise reduction device 11 is connected before the power switch 14 as described above.
Since it is interposed and provided on the introduction side of the connection line 27 to the power supply, noise induced in the power switch 14 and the connection line 27 to the power switch 14 can also be eliminated. In addition to the embodiments described above, the case may be constructed and arranged separately from the lamp. For example, like a chandelier lighting fixture, it may be separate from a case that houses a high frequency generator or the like.

The results of experiments conducted by the present inventors are shown below. A chandelier with five lamps each equipped with an annular fluorescent lamp with a rating of 30W, a power switch in the main body, a lighting device with a push-pull type transistor inverter that constantly oscillates at 33KHz, and a noise reduction device (balun transformer). In the case of shaped lighting equipment, the noise reduction device installed on the non-power side of the power switch had a noise between the power line and the ground of approximately 65 dB, whereas the noise reduction device according to this example had a noise of approximately 60 dB.
We were able to reduce it by 5dB.

Note that in this embodiment, the noise reduction device may be configured by combining an inductor, a capacitor, etc. instead of a balun transformer. However, the balun transformer is advantageous in that the impedance can be equivalently reduced to zero when viewed from the input side.

〔Effect of the invention〕

As described above, according to the present invention, the high frequency generator is housed in the middle part of the case where the connection line to the power source is introduced from one end side, and the operation part is installed at the other end side so that the operation part can be operated from outside the case. The device is equipped with a power switch, and a noise reduction device interposed between the power supply and the power switch is provided closer to one end of the case than the power switch, so that noise can be reduced through a direct noise feedback loop. Not only can the amount of noise induced in the power supply be greatly reduced, but also the high frequency noise induced in the power switch and the connection line to this switch via stray capacitance can be effectively reduced from returning to the power supply. , noise interference can be eliminated.

[Brief explanation of drawings]

1 and 2 show one embodiment of the present invention, with FIG. 1 being a circuit diagram and FIG. 2 being a plan sectional view showing a state where it is incorporated into a lighting equipment. 11...Noise reduction device; 13...AC power supply, 1
4...Power switch, 15...High frequency generator,
19... High frequency conversion device, 21... Discharge lamp.

Claims (1)

[Scope of Claims] 1. A case including a connection line connected to a power source from one end side; A high-frequency generator housed in the middle of the case and supplied with power from the power source to light a discharge lamp; a power switch for controlling the input to the high frequency generator on and off; an operating section is provided at the other end of the case so as to be operable from outside the case; A discharge lamp lighting device comprising: a noise reduction device provided on one end side of the power switch. 2. The discharge lamp lighting device according to claim 1, wherein the noise reduction device is constituted by a balun transformer.