JPS60257117A - Ballast for electric discharge lamp - Google Patents

Abstract

PURPOSE:To suppress the generation of noise when an electric discharge lamp is turned ON, by setting a frequency which reaches a maximum peak level among vibrations generated from a ballast element so that said frequency is a specific number of times as high as the intunsic frequency of the ballast main body. CONSTITUTION:A ballst element 1 is formed by winding a coil on an iron core 2, and a choke coil or a leakage transformer 4 is generally employed as the element 1. The transformer 4 is accommodated in a casing 5, together with a capacitor 6. A filling material 7 is filled in the space between the tranformer 4, the capacitor 6 and the casing 5. Thus, a ballast main body 8 having the element 1 incorporated in the casing 5 is formed. In the main body 8 having such arrangement, a frequency which reaches a maximum peak level among vibrations generated from the element 1 when the electric discharge lamp is turned ON is set so as to be at least 1.4 times as high as the natural vibration frequency of the main body 8. Thus, the occurrence of resonance between the main body 8 and the vibration generated from the element 1 is prevented, and the generation of large noise is thereby prevented when the electric discharge lamp is turned ON.

Description

[Detailed Description of the Invention] [Technical Field 1] The present invention relates to a discharge lamp ballast, and more particularly, to a discharge lamp ballast configured by incorporating a ballast element for a discharge lamp lighting circuit in a case. .

[Background Art 1] Generally, in ballasts for discharge lamps, alternating magnetic flux is generated due to the alternating voltage applied to the built-in ballast element, and this causes leakage of the transformer used as the ballast element. Vibrations occur in areas such as magnetic flux leakage areas and gigangs in the choke coil's iron core. In particular, in fluorescent lamp ballasts of the lead peak phase advancement circuit type that use a leakage transformer to light discharge lamps, the vibrations generated from the magnetic flux leakage part of the leakage transformer are an integral multiple of the commercial power supply, and the maximum peak level In many cases, the frequency of This is due to the harmonic components of the commercial power supply being included in the rise-L rise up to saturation.On the other hand, the ballast body, which is constructed with the ballast element built into the case, Since the mechanical natural vibration frequency of is generally several Kl(z), the ballast body may resonate with the vibrations generated by the ballast element, causing vibrations with a large amplitude.In this case, The vibration is at an audible frequency, and depending on the human audible characteristic, the frequency ranges from 1()00 to 5.
00 (l Since the resonance generated at l-1z is perceived as being larger than the frequency of the noise, it is perceived as even louder noise.

[Objective of the Invention 1] The present invention has been made in view of two points, and its main purpose is to reduce the vibration generated from the ballast element when the discharge lamp is turned on and to reduce the ballast element from the case. The objective is to prevent resonance with the ballast body built into the lamp and reduce noise when the discharge lamp is lit.

[Disclosure of the Invention 1 In the present invention, the frequency at which the maximum peak level of vibrations generated from the ballast element when lighting the discharge lamp is set to be 1.4 times or more the natural vibration frequency of the ballast body. discloses a structure that reduces noise generation during lighting of a discharge lamp.

The ballast element 1 has a coil 3 wound around an iron core 2, and generally a choke coil or a leakage transformer 4 is used. In this embodiment, as shown in FIG. 3, a leakage transformer 4 is used as a ballast element for a fluorescent lamp of lead peak phase advance circuit type. This leaky transformer 4 is housed in a case 5 together with a capacitor 6, as shown in FIG. A filling material 7 is filled between the leaky transformer 4 and the capacitor 6 and the case 5, and the leaky transformer 4 and the capacitor 6 are fixed in position within the case 5 by the filling material 7. The ballast main body 8 with the ballast element 1 built into the case 5 is constructed as described above, and the following experiments were conducted on various ballast main bodies 8 having such a configuration. As a result, the noise can be reduced by setting the frequency at which the maximum peak level of the vibrations of the ballast element 1 that occurs when the discharge lamp is lit is at least 11 times the natural vibration frequency of the ballast body E). It was found that the amount of water was reduced by about 6 to 9 bons.

In this experiment, as shown in FIG.
The ballast body 8 is vibrated by hitting the end of the pond, and the vibrations transmitted to the pick amplifier 10 by this vibration are detected by the observation device 11.
When a damped oscillation as shown in Figure 2 is observed, it is defined as the frequency of the most prominently observed oscillation among the i or damped oscillations. This natural vibration frequency r. It has been found that the value varies depending on the shape and structure of the case 53, the type of filler 7, the size of the ballast element 1, the placement position of the ballast element 1, etc. In addition, as shown in Fig. 3, a pick amplifier 10 for vibration detection is attached to the side of the magnetic flux leakage part of the leakage transformer 4 used as the ballast element 1, and when the discharge lamp is lit, the pick amplifier 10 is activated as shown in the figure. Vibrations generated in the left-right direction were detected, and the frequency of the vibration showing the maximum peak level among the vibrations observed by the observation device 11 connected to the pickup 10 was defined as r. The experimental results are shown in the table below. In this table, A, B, and C in the item "Case structure" correspond to Figures 5 (a), (b), and (c), respectively, and A means case 5 with one side. It is composed of a box body 12 that is opened and a lid plate 13 that closes the opening of the box body 12, and the peripheral edge of the opening of the main body 12 and the peripheral edge of the lid plate 13 are caulked together, and B is stable. It has a shape that goes around the periphery of the ballast element 1 and wraps around the ballast element 1, and its both ends are welded. and its both ends are caulked and connected.

■ ■ ■ − − − ” - If we graph the relationship between frequency ratio and noise among the results shown in the table, we can see that the frequency ratio is 1 as shown in Figure 4.
．． It has been found that when the number is 4 or higher, the noise becomes extremely loud. In the graph of Figure 4, × indicates a rapid type ballast element that lights two 4.0 W fluorescent lamps, and △ indicates]
1 (Rapid type ballast element that lights two IW fluorescent lamps, ◎ indicates a rapid type ballast element that lights one 40W fluorescent lamp.

[Effect of the Invention 1] As described above, the present invention has a ballast main body configured by housing a ballast element for a discharge lamp lighting circuit in a case, and stabilizes the frequency indicating the maximum peak level of vibration of the ballast element. Since it is 1.4 times or more higher than the natural resonant frequency of the ballast body, vibration generated by the ballast element and resonance with the ballast body are prevented, which prevents large noise from being generated when the discharge lamp is lit. It has the advantage of being

[Brief explanation of the drawing]

Figure 1 is a schematic sectional view showing an embodiment of the present invention, Figure 2 is a diagram showing an example of a waveform when measuring the natural vibration frequency of the same A perspective view showing an example of a ballast element, Fig. 4 is an operation explanatory diagram showing noise with respect to frequency ratio at 1-, and Fig. 5 (a) (1+)
(c) is a schematic sectional view showing the structure of the same case. 1 is the ballast element, 5 is the case, 3 (is the ballast body, ". is the natural resonant frequency of the ballast body, and [l is the frequency indicating the maximum peak level of the ballast element. Agent Valve I!li l2 stone III 艮 78-81

Claims (1)

[Claims] (1) The ballast body is constructed by housing the ballast element for the discharge lamp lighting circuit in a case, and the frequency indicating the maximum peak level of vibration of the ballast element when the discharge lamp is lit is the natural resonance of the ballast body. A discharge lamp ballast characterized in that the frequency is 1°4 times or more.