CN2146098Y

CN2146098Y - Protecting device for electronic ballast

Info

Publication number: CN2146098Y
Application number: CN 92234787
Authority: CN
Inventors: 沈咏元
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-09-30
Filing date: 1992-09-30
Publication date: 1993-11-10
Anticipated expiration: 2002-09-30

Abstract

The utility model relates to a protecting device for electronic ballasts, in which a PTC element (a positive temperature coefficient thermistor) is connected with the main circuit of the rectifier of an electronic ballast. When a fluorescent lamp generates abnormal faults, such as failure of starting, etc. The PTC element can perform a protective function, which makes the electronic ballast achieve the technical index of the national relevant trade standards, and the reliability of the electronic ballast is improved.

Description

Protecting device for electronic ballast

The utility model relates to a kind of protective device of electronic ballast for fluoresent lamp, especially uses the PTC(semistor) element makes the protective device of electric ballast.

At present, electronic ballast for fluoresent lamp is in the plastic casing the inside on the market, is connected by rectifier, oscillating circuit and fluorescent lamp, generally all is not provided with protective device.Over-voltage and over-current is taking place, particularly during fluorescent lamp abnormal condition " lamp does not start " (seeing industry standard ZBK74011-89 of the People's Republic of China (PRC) and ZBK74012-90), electric current by electric ballast increases suddenly, and the electronic component in the ballast will very easily damage because of electric current is excessive.The electric ballast of the band overvoltage crowbar that＜electronics newspaper〉the 22nd phase in 1992 of looking into is introduced needs to increase more than ten element, complex circuit, and cost is high again, maintenance difficult.

The purpose of this utility model provides a kind of protective device of electric ballast, can prevent effectively because the fluorescent lamp electric ballasts that abnormality caused such as " lamp do not start " damages.

The purpose of this utility model is achieved in that in the main circuit with the rectifier of PTC element connected in series in electric ballast, promptly is connected in the input (Fig. 1) of rectifier or is connected in rectifier output end (Fig. 2).The PTC element is the low resistance state when fluorescent lamp normally starts work.The input electric current of 40W fluorescent lamp electric ballast just often has only about 160 milliamperes, and the pressure drop on the PTC element is very little, does not influence the operate as normal of electric ballast and fluorescent lamp; When abnormalities such as " not starting " takes place in fluorescent lamp, increase to more than 300 milliamperes by the electric current of electric ballast is fast, the PTC element heightens because of heating makes its resistance; its pressure drop also heightens thereupon; at this moment, the voltage that is added on the electric ballast is just very low, thereby has protected this ballast effectively.The fluorescent lamp that more renews, get rid of abnormality after, automatically restore to the low resistance state again after the PTC element is cold, electric ballast again can operate as normal, lights fluorescent lamp.

Above-mentioned protective device can be protected electric ballast effectively, and only use a PTC element when abnormalities such as fluorescent lamp " does not start ", cost is very low, and circuit is very simple, and maintenance, assembling and repacking are all very convenient.

Cheat below and close drawings and Examples the utility model is further specified.

Fig. 1 is an electrical schematic diagram of the present utility model.

Fig. 2 is another embodiment electrical schematic diagram of the present utility model.

Among the figure, 1PTC element, 2 rectifiers, 3 oscillating circuits, 4 fluorescent lamps.Electric ballast is that 2 and 3 two parts are formed.

In Fig. 1, PTC element (1) is connected in the input of rectifier, is that an end and power line join, and the other end and rectifier join.

In Fig. 2, PTC element (1) is connected in the output of rectifier, is that an end and rectifier join, and the other end and oscillating circuit join.

The utility model also can be to electric ballast itself and fluorescent lamp during because of accidents such as excessive generations of line current are fiery glimmering, and defencive function is arranged.

Facts have proved when the utility model can be implemented in faults such as fluorescent lamp generation abnormality, protect electric ballast effectively.Apply this protective device, can produce the more reliable electric ballast of quality, social benefit and economic benefit all are good.

Claims

1, a kind of electric ballast is in plastic casing, is made up of also and the fluorescent lamp connection rectifier, oscillating circuit, and the protective device that it is characterized in that it is connected in the main circuit of rectifier with a PTC element (semistor).

2, electronic ballast protection device according to claim 1 is characterized in that the PTC element is connected in the input of rectifier, is that an end and power line join, and the other end and rectifier join.

3, electronic ballast protection device according to claim 1 is characterized in that the PTC element is connected in the output of rectifier, is that an end and rectifier join, and the other end and oscillating circuit join.