Relay for radio circuit and electronic ballast employing the relay

Abstract

The invention relates to a relay used in fluorescent lamps, more particularly T5 fluorescent lamps, and an electronic ballast using the relay. The relay comprises a shell, a fixed contact and a dual-metal sheet both sealed inside the shell, and an inert gas filled inside the shell. The fixed contact and the dual-metal sheet, at one end, are respectively led out of the shell to form electrode outlet terminals, and the two electrode outlet terminals are connected in parallel with the start capacitor of the electronic ballast. During the start-up, the relay can pre-heat the fluorescent lamp to prevent the burn-out of fluorescent lamp due to instantaneous illumination. Additionally, the T5 fluorescent lamp needs a high start voltage, particularly the T5 fluorescent lamp requires pre-heat treatment when applied to the T8 or T10 lamp holder, therefore, the invention helps for the popularization and application of T5 fluorescent lamps.

Description

Technical field [0001] The present invention relates to the field of lighting, in particular to an electronic ballast applied to a T5 fluorescent lamp and a relay applied to the electronic ballast. Background technique [0002] At present, there are roughly two types of fluorescent lamps sold and used in the market, one is T8, T10 fluorescent lamps and their supporting lamps, the other is T5 fluorescent lamps and their supporting lamps, and the latter belongs to a new generation of light source products. Compared with T8 and T10 fluorescent lamps, they have the advantages of energy saving, high luminous efficiency, high color rendering index and long working life. They have gradually been favored by people, but for some users who are already using T8 and T10 lamps, such as in factories and schools In large places such as supermarkets, supermarkets, etc., if you want to switch to T5 light source, due to the inconsistency of the specifications of the two lamp holders and the incons...

AI Technical Summary

Problems solved by technology

[0002] At present, there are roughly two types of fluorescent lamps sold and used in the market, one is T8, T10 fluorescent lamps and their supporting lamps, the other is T5 fluorescent lamps and their supporting lamps, the latter belongs to a new generation of light source products, it is the same as Compared with T8 and T10 fluorescent lamps, they have the advantages of energy saving, high luminous efficiency, high color rendering index, and long working life, and have gradually been favored by people. However, for some users who are already using T8 and T10 lamps, such as in factories and schools , Supermarkets and other large places, if you want to switch to T5 light source, due to the inconsistent specifications of the two lamp holders and the inconsistent length of the lamp tube, the T5 lamp cannot be directly applied to the T8 and T10 lamp holders. There are several existing technologies in the prior art. A converter that enables T5 lamp tubes to be applied to T8 and T10 lamp holders, such as the Chinese utility model patent with the publication number 200520144489.6 and the Chinese utility model patent with the publication number 03231029.3. There are two plugs on the body with jacks on the other end. Insert the plug of the T5 lamp tube into the jack on the body, and insert the plug on the body into the T8 and T10 lamp holders to realize the connection between the T5 lamp tube and the T8 and T10 lamps. Although the original T8 and T10 lamp holders can still be used, it is necessary to remove the lamp holder, re-change the circuit, and install an electronic ballast to make the lamp work.

[0003] The existing electronic ballast consists of a rectification filter circuit, a high-frequency oscillation circuit, a half-bridge drive circuit and a lamp output circuit, as shown in Figure 1. This kind of electronic ballast is applied to a T5 lamp. When it is started, City AC enters through 220V / 50HZ through PIN1 and PIN2, and is filtered by bridge rectifier D1~D4 and electrolytic capacitor C1, so that 220V AC becomes 300V DC. In the case of 300V DC power supply, transistor T1 and transistor T2 Working alternately, a high-frequency, series, self-excited resonant circuit is formed, so that the DC 300V becomes a high-frequency AC, which is output by the transistor T1 and the transistor T2 half-bridge, and the point A becomes a high-frequency (40kHZ~50kHZ) voltage, through the choke The flow coil TIB supplies the lamp tube, and the starting capacitor C5 of the lamp tube resonates with the choke coil TIB. At the time of resonance, the voltage VC5 applied to both ends of the lamp tube is several times the half-bridge output voltage (voltage at point A), that is, QVC5 (Q is the quality factor of the series resonant circuit), due to the thinning of the T5 lamp tube, the starting voltage of the lamp tube is much higher than that of T8 and T10 (the starting voltage of the T5 lamp reaches 800V, and the starting voltage of the T8 and T10 lamp 400V), because the electronic ballast circuit has no preheating protection function, the lamp will light up when it is turned on, which belongs to cold cathode emission, which will seriously damage the cathode of the lamp tube, and the electronic powder will sputter on the tube wall, making the lamp The premature blackening of the tube shortens the life of the lamp, and impacts the electronic components in the electronic ballast, which damages the electronic ballast or shortens its life. That is, if the T5 lamp is to be applied to the existing T8 / On the T10 lamp holder, with the help of the electronic ballast in the prior art, although the T5 lamp can be started, but due to the high starting voltage, one is that the lamp tube is very easy to turn black due to no preheating, and the other is the impact when starting. And the lamp tube is often easy to break down the transistors T1 and T2 in the electronic ballast in an abnormal state, so that the entire electronic ballast is damaged

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