CN2518297Y

CN2518297Y - Electronic ballast of fluorescent light

Info

Publication number: CN2518297Y
Application number: CN 01263105
Authority: CN
Inventors: 李博; 李先栗
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-10-08
Filing date: 2001-10-08
Publication date: 2002-10-23
Anticipated expiration: 2011-10-08

Abstract

The utility model relates to an electron ballast of a fluorescent lamp with reliable error state protecting function. The utility model adopts that a fluorescent tube is directly connected with a tickler coil in a circuit; the two ends of the connecting circuit are connected with an overvoltage time closing switch in a parallel way or an overvoltage timing relay. When the fluorescent tube cannot be ignited normally, the switch or relay makes a time closing action, thus the oscillation of the circuit stops, thereby effectively protecting a transistor from the damage caused by the overload. The utility model has the advantages that the structure of the circuit is simple and the protecting function is very reliable.

Description

Electronic ballast for fluoresent lamp

The utility model relates to a kind of electronic ballast for fluoresent lamp, especially a kind of electronic ballast for fluoresent lamp with reliable abnormal condition protection function.

At present; the structure more complicated of abnormal state protection circuit in the known circuit of fluorescent lamp electronic ballast; generally comprise 10 to 16 components and parts (referring to " lamp and illumination " 1998/4; P33 Fig. 1); this not only makes cost raise; " mistake protection " more seriously usually occur and have little time phenomenon such as protection; the result is that the failure rate and the user's return of goods rate that have added the product of protective circuit raise on the contrary; so that many factories have simply removed abnormal state protection circuit on circuit board, but such product is not meet the low-quality goods that GB requires.In order effectively to improve the reliability of electronic ballast for fluoresent lamp, reduce spoilage, need seek new abnormal state protection circuit.

The purpose of this utility model is exactly that a kind of circuit of fluorescent lamp electronic ballast structure with reliable abnormal condition protection function will be provided, the element that its abnormal state protection circuit part is comprised seldom, operation principle is simple, defencive function is very reliable.

The purpose of this utility model is achieved in that in the vibration of transistor HF switch and output circuit of existing circuit of fluorescent lamp electronic ballast, the coil L that will be used to feed back ₁FL directly is connected in series with fluorescent tube, and at coil L ₁Away from the end a point of fluorescent tube FL and fluorescent tube FL away from coil L ₁C/e point overvoltage timing closing K switch in parallel of an end with two lead-out wires, or at coil L ₁An end a point, fluorescent tube FL and coil L away from fluorescent tube FL ₁The b/d point of an end that is connected and fluorescent tube FL are away from coil L ₁The c/e point of an end connect an overvoltage time delay closing relay J with three lead-out wires, wherein 2 of a, b/d are connected with two lead-out wires of the contact switch part of J respectively, the c/e point is connected with another root lead-out wire of J.When fluorescent tube FL occur can not normal ignition abnormality the time, two ends b/d, the c/e of fluorescent tube F L and a, c/e point-to-point transmission will continue to occur too high voltage, make overvoltage retarded closing K switch or overvoltage time delay closing relay J produce the switch motion of retarded closing, with a, c/e or 2 short circuits of a, b/d, so flow through the coil L that is used to feed back ₁Electric current be zero, circuit is failure of oscillation immediately, thus protective transistor makes it avoid working in not normal ignition and OL abnormality takes place of fluorescent tube; If the fluorescent tube normal ignition, b/d, c/e and a, c/e point-to-point transmission voltage are relatively low normal value, and K/J will can not produce the switch motion of timing closing and keep normal off-state, circuit not produced any influence.

Owing to adopt such scheme; in fact the abnormal state protection circuit of electronic ballast for fluoresent lamp has only element of K/J; and defencive function is very reliable, has not only improved the performance of electronic ballast for fluoresent lamp, has also obviously reduced cost and the area that has dwindled circuit board.

Below in conjunction with accompanying drawing and embodiment the utility model is further specified.

Fig. 1 is the relevant circuit diagram of the utility model embodiment 1.

Fig. 2 is the relevant circuit diagram of the utility model embodiment 2.

Fig. 1 and Fig. 2 are respectively oscillatory trigger circuit and the vibration of transistor HF switch and the output circuit of 5 watts of electronic ballast for fluoresent lamps and 36 watts of electronic ballast for fluoresent lamps.K is the overvoltage timing closing switch with two lead-out wires among the figure; J is the overvoltage time delay closing relay with three lead-out wires; L1, L2, L3 are the coil that oscillating circuit is used to feed back; L is an inductance.Wherein K and J all can be the gas discharge switch with bimetal type moving plate and inertia working gas; Also can be thermomotive time-delay relay (or thermomotive delay switch) with bimetal type moving plate and piezo-resistance heater.The major parameter of K/J is 150 volts of minimum conducting voltage; 250 volts of the highest operation voltages; 0.5 ampere of specified switching current.

Because circuit working principle among the figure except that K/J and component parameter and existing homogeneous circuit are similar, so need not to be illustrated one by one.

Claims

1, a kind of electronic ballast for fluoresent lamp, mainly constitute by anti-electromagnetic interference circuit, rectification and filter circuit, circuit of power factor correction, oscillatory trigger circuit, transistor switch vibration and output circuit etc., it is characterized in that wherein the transistor switch vibration and the coil L that is used to feed back in the output circuit ₁FL directly is connected in series with fluorescent tube, and at coil L ₁Away from the end a point of fluorescent tube FL and fluorescent tube FL away from coil L ₁C/e point overvoltage timing closing K switch in parallel of an end with two lead-out wires, or at coil L ₁An end a point, fluorescent tube FL and coil L away from fluorescent tube FL ₁The b/d point of an end that is connected and fluorescent tube FL are away from coil L ₁The c/e point of an end connect an overvoltage time delay closing relay J with three lead-out wires.

2, a kind of electric ballast as claimed in claim 1 is characterized in that wherein overvoltage delay switch K or overvoltage time-delay relay J are the gas discharge switch with bimetal type moving plate and inertia working gas.

3, a kind of electric ballast as claimed in claim 1 is characterized in that wherein overvoltage delay switch K or overvoltage time-delay relay J are moving delay switch of heat or the moving time-delay relays of heat with bimetal type moving plate and piezo-resistance heater.