CN2212875Y

CN2212875Y - Multifunctional assembly for electronic ballast

Info

Publication number: CN2212875Y
Application number: CN 94241156
Authority: CN
Inventors: 李建平
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-08-23
Filing date: 1994-08-23
Publication date: 1995-11-15
Anticipated expiration: 2004-08-23

Abstract

The utility model discloses a multifunctional assembly for an electronic ballast. When the utility model is used for replacing a resonant capacitor of a common electronic ballast, the functions of filament preheating and abnormal state protection are added to the common electronic ballast, and thus, the service life of lamp tubes and the electronic ballast is prolonged. The utility model is suitable for electronic ballasts of various common fluorescent lamps and energy-saving lamps.

Description

The electric ballast multifunctional module

The utility model relates to a kind of multifunctional module that is used for the ordinary electronic ballast, particularly a kind of electric ballast multifunctional module that can make the ordinary electronic ballast increase filament pre-heating and abnormal condition protection function.

At present domestic ordinary electronic ballast adopts series resonance to produce the light a lamp starter mode of pipe of high pressure instantaneous point mostly, owing to do not carry out filament pre-heating, filament is in the pop-up electronic state, has caused splashing of filament electron-emissive material, the major injury fluorescent tube has reduced useful life.Simultaneously; this electric ballast scarcely possesses the abnormal condition protection function, and when the consumption of filament electron-emissive material is made a gift of to the greatest extent, fluorescent tube is normally during starter; series resonant circuit can produce for a long time, great resonance current, and this electric current can make the serious heating of active power device and damage.So fluorescent tube damages back as untimely replacing, promptly may cause the damage of electric ballast.

The method of existing solution filament pre-heating problem is: PTC resistance in parallel again at the resonant capacitance two ends in parallel with fluorescent tube.The shortcoming of this method is: during tube starting, there is very high voltage at PTC resistance two ends, fluorescent tube with the old situation that is difficult for starter under, this voltage can be up to 800 volts, present PTC resistance is easy to punch through damage under so high voltage.Existingly to fluorescent tube with the old guard method that situation adopted that can not starter be: the output current to electric ballast is taken a sample, and when electric current is excessive, forces the electric ballast power device to turn-off.The defective of this mode is: have no progeny when power device closes, the output current of electric ballast is zero, and sampling current disappears immediately, and this can make electric ballast restart work; Like this, electric ballast will work in the recurrent state of protection-work-protection repeatedly, still have bigger resonance current to occur in the quite a while, and the heating of power device is also relatively more serious.Simultaneously, the circuit of this protected mode and the tie point of electric ballast are more, only are fit to be contained in electric ballast inside, are difficult to from the outside now transforming at the ordinary electronic ballast of the unprotect function of using.

In order to restrain the easily breakdown weakness of PTC resistance in the existing electric ballast with filament pre-heating function of eye, improve the functional reliability of preheat function, the utility model is connected in parallel on the resonant capacitance two ends with a relay normally-closed contact replacement PTC resistance and carries out filament pre-heating, its course of work is: when electric ballast rigidly connects energize, relay normally-closed contact closure, resonant capacitance is by short circuit, carry out filament pre-heating, after after a while, normally-closed contact disconnects, the inductance of resonant capacitance and electric ballast inside produces series resonance, makes tube starting.Can not starter if fluorescent tube damages, abnormal state protection circuit can make the normally-closed contact of relay closed again, finishes protection with this; This state has only power cutoff to remove, and this has just been avoided occurring repeatedly the situation of resonance current.The electric ballast multifunctional module is realized the conversion of preheating and starter state with the break-make of relay contact, and withstand voltage than high many of PTC resistance, reliability is greatly improved.In addition, because the electric ballast multifunctional module has only two lead-out wires, also can will be transformed into electric ballast at the ordinary electronic ballast that uses from the outside easily with filament pre-heating and abnormal condition protection function.

Accompanying drawing 1 is a structured flowchart of the present utility model, and it is made up of resonant capacitance (1), rectification circuit (2), relay (3), delay circuit (4) and protective circuit (5).Whole assembly is directly parallel in lamp tube ends.

Accompanying drawing 2 is embodiment circuit of the present utility model.Among the figure; (C1) be resonant capacitance; diode (D1), (D2) form rectification circuit; delay capacitor (C2), time delay resistance R and multiple tube BG form delay circuit; voltage-stabiliser tube (D3), adjustable unijunction transistor (PTU) are formed protective circuit; (J) being relay coil, (J1) is the normally-closed contact of relay, (C3) is filter capacitor.

During energized, relay normally-closed contact (J1) is with resonant capacitance (C1) short circuit, and lamp tube ends voltage is very low, and fluorescent tube is in the filament pre-heating state.At this moment, the electric current that flows through filament is added on relay coil (J) and delay circuit (BG), (C2), (R) after (D1), (D2) rectification, because the initial voltage (C2) is very low, voltage between multiple tube (BG) collector electrode and emitter is also very low, and relay is failure to actuate.Along with the charging to (C2) of the base current of multiple tube (BG) and time delay resistance (R), (C2) voltage on raises gradually, and the voltage on the relay coil (J) also increases; When this voltage is elevated to the pick-up voltage of relay, the actuating of relay, warm finishes, and normally-closed contact (J1) disconnects, and (C1) with the interior inductance generation series resonance of electric ballast, makes tube starting.The electric current of (C1) of behind the starter, flowing through can make relay keep attracting state after rectification.Can not starter if fluorescent tube damages; (C1) be in resonance condition all the time, the electric current that flows through (C1) is very big, and this electric current can make the voltage on the electric capacity (C2) further raise; puncture until voltage-stabiliser tube (D3); trigger adjustable unijunction transistor (PTU), make it conducting, (C2) discharged; voltage between multiple tube collector electrode and base stage descends; relay discharges, and gets back to preheat mode, has realized abnormal condition protection.When the normal starter of fluorescent tube, starting time is very short, and (C2) voltage on can not be elevated to the puncture voltage of (D3), the misoperation of protective circuit can not occur.

Claims

1, a kind ofly be connected in parallel on lamp tube ends, by the electric ballast multifunctional module that resonant capacitance (C1), the relay (J) that has a normally-closed contact (J1), NPN type compound transistor (BG), delay capacitor (C2), time delay resistance (R), rectifier diode (D1), (D2) form, are used for increasing filament pre-heating function and abnormal condition protection function to electronic ballast for fluoresent lamp, it is characterized in that resonant capacitance (C1) is in parallel with the normally-closed contact (J1) of relay (J).

2,, it is characterized in that the coil two ends of relay (J) are connected with the collector and emitter of NPN type compound transistor (BG) respectively according to the described electric ballast multifunctional module of claim (1).

3,, it is characterized in that being parallel with delay capacitor (C2) between the collector electrode of NPN type compound transistor (BG) and the emitter according to claim (1), (2) described electric ballast multifunctional module.