JPS6396807A - Lighting fixture - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Objective of the Invention) (Industrial Field of Application) The present invention relates to a lighting fixture having a built-in lighting device for lighting a light source at high frequency.

(Prior Art) Conventionally, in lighting fixtures that include a built-in lighting device for lighting a light source at high frequency, the high frequency noise generated by the lighting device has an adverse effect on other electrical equipment. This high frequency noise includes conduction noise conducted through electric wires, and radiation noise radiated from light sources, electrical parts, etc., and it is necessary to reduce both of these noises. For this reason, conventionally, a conductive case housing a high frequency generator is connected to an input power supply line via a capacitor or the like, so that the conductive case has a shielding effect.

(Problems to be Solved by the Invention) However, such conventional technology is not used for lighting fixtures with double insulation structure. The present inventors have confirmed that sufficient effects cannot be obtained if The reason for this is that with double-insulated lighting fixtures, the fixture itself cannot be connected to the input power line, so the fixture body receives radiation noise from the light source, electrical components, etc., and generates noise voltage. It is assumed that this equipment body radiates high frequency noise or applies high frequency noise to the input wire via distributed capacitance. .

Regarding double insulation of lighting equipment, Japanese Industrial Standards (
JIS C8132).

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a lighting fixture that can reduce the problem of high frequency noise without impairing the double insulation structure.

[Structure of the invention]

(Means for Solving the Problems) The present invention has a conductive instrument body equipped with a light source, a high frequency generator for energizing the light source, and a conductive case containing the high frequency generator, a lighting device housed in a device body with double insulation applied to the device body; a first capacitor connected between the conductive case and an input power line to the high frequency generator; The device is characterized by comprising a second capacitor connected between the device main body and the conductive case.

(Function) In the present invention, since the conductive case is connected to the input power line through the first capacitor, the conductive case can act as a shield body, and the instrument main body can be connected to the input power line through the first capacitor.
Since it is connected to the conductive case through the capacitor,
This instrument main body is connected to the input power supply line via the conductive case and the first capacitor, and this instrument main body can also act as a shield body. That is, the conductive case and the main body of the device can be considered to have the same potential as the input power source, which has a stable potential, with respect to high frequencies.

Furthermore, since the present invention connects the main body of the device to the conductive case via the second capacitor, the above JIS C8
without compromising the protective insulation specified in 132,
Therefore, the double insulation structure is not damaged.

In the present invention, the light source may be either a light bulb or a discharge lamp, and the high frequency generator is one that increases or decreases the voltage to adapt to the voltage required by the light bulb or discharge lamp, for example. In order to raise or lower the voltage in this way, it is advantageous to use a high-frequency generator to reduce the size and weight.

(Example) An example of the present invention will be described below with reference to FIGS. 1 to 3. Reference numeral 1 denotes a conductive instrument body to which a light source 2 is attached. The details of the device main body 1 will be omitted from illustration and description, but it may be of a well-known structure made of iron, aluminum, or the like. 3 is a lighting device,
The device includes a high frequency generator 4 for energizing the light source 2, and a conductive case 5 containing the high frequency generator 4. The high frequency generator 4 and the case 5 are constructed with functional insulation specified in JIS C8132, and specific means for such functional insulation are well known. The case 5 is made of aluminum group, for example. The lighting device 3 is housed within the appliance main body 1 while being protected and insulated from the appliance main body 1. Therefore, due to the functional insulation and protective insulation, the lighting device 3 and the appliance main body 1 have a double insulation structure. Note that the specific means for the protective insulation is well known. The high frequency generator 4 is a chopper.

Although any type of inverter or the like may be used, this embodiment mainly consists of a transistor inverter 41, as detailed in FIG. 2.

The structure of this transistor inverter 41 itself is well known. 42 is a rectifier connected to the input power supply lines 6 and 7, and 43 is a common mode choke coil for a filter provided before the rectifier 42.

A first capacitor 8 is connected between the conductive case 5 and the input power lines 6 and 7.

In this embodiment, since it is connected to the input side of the rectifier 42, it consists of a pair of capacitors. Furthermore, in the case of this embodiment, the first capacitor 8 also functions as a so-called line-to-line noise filter. Note that the first capacitor 8 can also be connected to the output side of the rectifier 42. In this case, the number of first capacitors 8 can be one. Reference numeral 9 denotes a second capacitor, which is connected between the instrument main body 1 and the conductive case 5.

Next, the operation of this embodiment will be explained. The light source 2 is lit by the operation of the high frequency generator 4 of the lighting device 3. The operation of this high frequency generator 4 and the lighting of the light source 2 generate high frequency noise. However, conductive case 5
Since it is connected to the input power supply lines 6 and 7 via the first capacitor 8, it acts as a shield for the high frequency generator 4. Furthermore, the conductive case 5 itself is kept at the potential of the input power source at high frequency. The device body 1 also has a second capacitor 9. It is connected to input power supply lines 6 and 7 via a conductive case 5 and a first capacitor 8, and this instrument body 1 also acts as a shield and is kept at a stable potential at high frequencies. As a result, the noise terminal voltage conducted through the input power supply lines 6 and 7 and the intensity of interference waves radiated from the light source 2° instrument body 1, etc. can be reduced.

The experimental results of this example are shown below. Note that the light source 2 was a 75W metal halide lamp, and the high frequency generator 4 outputted a voltage in which a triple frequency component was superimposed on a fundamental wave component of 120 kHz. Further, the first capacitor 8 was connected to the output side of the rectifier 42 . FIG. 3 shows the measurement results, where A indicates the case where the second capacitor 9 is not provided and a 0.015 μF capacitor 8 is used as the first capacitor 8, and B indicates the case where the first capacitor 8 is used. Second capacitor 8.9
When a 22009F capacitor is used as
This is the noise terminal voltage value between one line and the ground when using an F capacitor. The contents in the figure show the standards of the Electrical Appliance and Material Control Law. As is clear from FIG. 3, the device according to the present invention can significantly reduce the noise terminal voltage compared to the conventional device. Also, 1st. Although it is more effective to increase the capacitance of both the second capacitors 8 and 9, they can be selected in consideration of price and other factors within a range that satisfies the standards.

Regarding the interference wave intensity, the one corresponding to Figure 3A reached its maximum value at 380kllZ and the value was 70dB, while the one corresponding to Figure 3C also reached a maximum value of 360kllZ.
The maximum value was 58 dB at Hz, which resulted in a reduction of 12 dB. Although the above experimental results are only for - conditions, if other conditions are the same, the results of the present invention were found to have the same effects as those described above compared to the conventional methods.

〔Effect of the invention〕

As described above, the present invention provides a lighting fixture with a double insulation structure, in which the first capacitor is connected between the conductive case containing the high frequency generator and the input power line, and
Since the second capacitor is connected between the device main body and the conductive case, the double insulation structure can be
Since the conductive case and the instrument main body can act as a shield, the noise terminal voltage and the interference wave intensity can be significantly reduced.

[Brief explanation of the drawing]

Figures 1 to 3 show one embodiment of the present invention.
The figure is a block diagram, and Figure 2 is a circuit diagram of the main parts. FIG. 3 is a curve diagram showing the experimental results. 1... Appliance body, 2... Light source, 3... Lighting device. 4... High frequency generator, 5... Conductive case. 6.7... Input power supply line, 8... First capacitor. 9...Second capacitor. Patent applicant Toshiba Electric Materials Co., Ltd. Agent Patent attorney Ono 1) Engraving of drawing by Yoshihiro (no change in content) Figure 1 2. Name of invention Lighting device 4. Agent

Claims (1)

[Claims] (1) A conductive instrument body equipped with a light source; a high frequency generator for energizing the light source; and a conductive case containing the high frequency generator; A lighting device housed with heavy insulation; A first capacitor connected between the conductive case and the input power line to the high frequency generator; Between the appliance body and the conductive case. A lighting device comprising: a second capacitor connected to the device; and a second capacitor connected thereto.