CN2068744U - Electronic ballast with various kinds of protective circuit - Google Patents

Abstract

The utility model discloses an electronic ballast with various protective circuits relating to the technical field of the control of luminous electrons of an electric light source. The utility model is composed of a rectification circuit, a filter circuit, a lamp tube single trigger glow starting control circuit, a common emitter high frequency electronic inverter circuit, various protective circuits, etc. The daylight lamp which adopts the utility model generally has the advantages of power saving, light weight, no noise, long service life, low glow starting voltage, no stroboflash, soft and safe light ray, etc., being able to be used in the circuits of the daylight lamps with various types and sizes.

Description

Electronic ballast with various kinds of protective circuit

The utility model relates to the employed electric ballast of daylight light fixture of all kinds, specification, belongs to and electric light source luminous electron control technology field.

Disclosing the circuit of a kind of crying " VMOS pipe electronic ballast device " on February 26th, 1986 " electronics newspaper " on the 7th phase, is exactly in fact a kind of circuit of electronic ballast.This circuit provided a kind of electric ballast typically, comparatively complete circuit structure.This circuit adopts the VMOS pipe as oscillating tube, characteristics such as conducting speed is fast though it has, power utilization efficient height, and this pipe is too fragile, and is fragile, limited the brightness of sending out of its superiority in a sense; Disclose a kind of electric ballast on " radio " magazine in April, 1987; VMOS pipe is wherein changed into transistor, thereby but lack pressure limiting, current-limiting protection circuit in base stage, emitter circuit and other places of pipe and influenced its functional reliability to a certain extent.In addition, these two kinds of circuit all lack lengthen the life protection device and power connection state of fluorescent tube and change the personal safety protective circuit of fluorescent tube down, thereby still need in addition perfect.

The purpose of this utility model be to provide one kind of multiple protective circuits, the reliable electric ballast of more stable work, make it not only to have to be better than traditional iron inductance formula ballast, and characteristics and the performance that is better than some existing electric ballast arranged.

The utility model is made up of circuit and shell two parts, and wherein circuit part is a key component of the present utility model, and mainly by rectification and filter circuit, a starter trigger control circuit, common emitter high-frequency electronic inverter circuit, kinds of protect circuit etc. are formed for it.That the fluorescent lamp that this kind ballast is housed generally has is in light weight, energy-conservation, open wave voltage low, trigger sensitive, reliable and can one time starter, no arcing, noiseless, no stroboscopic and light is soft, the fluorescent tube long service life, even and change fluorescent tube when power connection is arranged and also can guarantee characteristics such as personal safety, thereby can be widely used in the daylight light fixture of all kinds, specification.

Accompanying drawing 1 is an electrical schematic diagram of the present utility model;

Accompanying drawing 2 is schematic appearance of the present utility model (being called for short DZLQ);

Accompanying drawing 3 is methods of attachment of the utility model and various types of fluorescent lamp (L).Wherein Fig. 3 a is the method for attachment of electric ballast and general fluorescent tube; Fig. 3 b is electric ballast and the filament method of attachment of disconnected general fluorescent tube; Fig. 3 c is the method for attachment of special-shaped fluorescent tubes (HL) such as electric ballast and H type.

The embodiment that provides below in conjunction with accompanying drawing describes operation principle of the present utility model in detail.

As shown in Figure 1, the alternating current of 220V/50HZ is added on by capacitor C after by the bridge rectifier DBR rectification of being made up of 4 semiconductor diodes ₁, C ₂And resistance R ₀Produce the high direct voltage about 330V behind the filter circuit of forming, used for entire circuit.BX among the figure is a fuse, and the resistance R in it and the filter circuit all can shield, when making the excessive or line voltage of electric current too high and circuit individual metablocks device go wrong and guarantee the safety of electric ballast when causing overcurrent.Here adopt two capacitances in series filtering, purpose is the requirement of withstand voltage that reduces single electric capacity.R among the figure ₃, C ₃, bidirectional trigger diode D ₁, isolating diode D ₂Form together by " starter control circuit of fluorescent tube ", its effect is to guarantee after the energized starter of fluorescent tube, and makes circuit working stable.After energized, rectified direct current passes through R ₃Give C ₃Charging.Work as C ₃On voltage reach D ₁Conducting voltage after, D ₁Conducting rapidly, and the transistor T in the high-frequency electronic inverter circuit ₂Base stage provides Control current, triggers the inverter circuit starting of oscillation, T ₂During conducting, capacitor C ₃On voltage by isolating diode D ₂, triode T ₂Discharge rapidly.Because the inverter circuit operating frequency is very high, R ₃C ₃Time constant bigger again, so inverter in case work, C ₃Go up just again not set up and make D ₁The voltage of conducting promptly guarantee once to trigger starting of oscillation, and starter is lighted fluorescent tube.D ₂This buffer action guaranteed that circuit oscillation is stable, this also just is not easy to take place the arcing phenomenon.Transistor T ₁, T ₂, resistance R ₁, R ₂, R ₄, R ₅, oscillatory feedback inductance coil of wire L ₁, L ₂, L ₃Form common emitter high-frequency electronic inverter circuit.As can be seen from the figure, vibration inductance L ₁, L ₃Respectively and resistance R ₂, R ₄Be connected on oscillating tube T after the series connection respectively ₁, T ₂Base loop in, in addition as " end of the same name " method of attachment of figure regulation, the very easily starting of oscillation of this circuit.After the starting of oscillation, T ₁, T ₂Be alternate conduction, and the work wave between A, the N is the square wave shape.R among the figure ₁, R ₄, R ₂, R ₅Play current limliting and negative feedback protective effect, make oscillating tube T ₁, T ₂Be difficult for puncturing or burning because of overcurrent because of overvoltage.Oscillating voltage passes through L ₂Coupling output, Chuan Lian C with it ₄Play the stopping direct current effect.Ballast transformer B ₁Elementary, capacitor C ₇Form the electrical appliance loop with fluorescent tube L.As can be seen from the figure, B ₁Elementary and C ₇Form series resonance and swing circuit, fluorescent tube is connected in parallel on capacitor C ₇On.After beginning energized and inverter circuit starting of oscillation, pulse square wave passes through C ₄Be added on by B ₁Elementary and C ₇Make it that resonance takes place on the series resonant tank of forming, resonance frequency F is approximate to be used

Expression, wherein Lb ₁Be B ₁Primary inductance.Because Lb ₁, C ₇The resonant tank of being formed has quality factor much larger than 1 (be Q " 1), thus fluorescent tube L not during starter, C ₇On voltage can be supply voltage Q doubly, reach kilovolt, be enough to make tube starting.In case lamp lighting-up, B ₁Promptly play the ballast effect.The diode D that is in parallel with the filament 1,2 and 3,4 of fluorescent tube L among the figure ₄, D ₅Can prevent the overtension on the filament, have the protective effect that prevents the early stage blackout of fluorescent tube, help the useful life of extended day light modulation.R in the circuit ₆, C ₆Be the inertia anti-jamming circuit, can prevent effectively that electric ballast from producing the interference to other electrical appliances, especially to the wireless interference of medium wave.Among the figure, by B ₁Secondary 5-6, diode D ₃, capacitor C ₅, resistance R ₇, R ₈, R ₉, R ₁₀, triode BG ₂, BG ₁Form the output open circuit protective circuit.When operate as normal, B ₁Secondary induction goes out the voltage of certain amplitude, through D ₃After the rectification at C ₅Last generation voltage is through biasing resistance R ₇Make BG ₂Conducting is to the greatest extent and at R ₈Last generation pressure drop makes BG ₁End.Because BG ₁Present very big impedance between its collector and emitter when ending, though it is connected in parallel on oscillating tube T ₂Base stage and emitter between, but do not influence the work of inverter.Resistance R ₉, R ₁₀Play the dividing potential drop effect, make BG ₁, BG ₂Voltage supplied unlikely too high.As fluorescent lamp tube open circuit (when promptly changing fluorescent tube), B ₁Elementary no current, thereby its secondary induction do not go out voltage, so BG ₂End BG ₂Collector electrode be high level, thereby BG ₁Conducting is low impedance state between its collector and emitter, with oscillating tube T ₂The short circuit of base emitter-base bandgap grading, inverter circuit is left alone without help to shake thereby make.Like this, just do not have voltage output,, do not have what danger yet, can shield personal safety even the people runs into the socket lead-in wire of fluorescent tube because of carelessness.

The utility model has adopted the kinds of protect circuit, and reliability is higher.But because of the transistor T in the inverter circuit ₁, T ₂Be operated in the inevitable phenomenon of more or less generating heat high-power time.In order to make circuit working more reliable, be at T ₁, T ₂Last radiation fin.Like this, generally just do not need maintenance, can be placed on it in plastic housing of air vent hole or seam, can be placed in the metal-back of doing with iron yet.The shell that the utility model adopts is preceding a kind of, as shown in Figure 2.Wherein 1 is plastic casing, and 2 are the heat radiation louver, and 3 are lead-in wire, and 4 is fixing threaded hole, in order to electric ballast is fixed on the lamp bracket.The circuit board section of whole electric ballast just is fixed within the shell.

Major advantage of the present utility model be in light weight, trigger sensitive, easily starting of oscillation, starting voltage is low, power factor is high, working stability, have various kinds of protective circuit; thereby it is energy-conservation to use fluorescent lamp of the present utility model generally to have; noiseless; no stroboscopic, light is soft and be conducive to vision protection, no arcing; but can turn black in early days by a starter preventing light tube; thereby the fluorescent tube long service life, wide accommodation is conducive to guarantee personal safety. This utility model not only can be used in the general fluorescent lamp, also can be used in the special-shaped lamp such as H type, but also can make the disconnected general old fluorescent tube " recovery " of filament. In addition, need not change circuit structure, only change the individual circuits parameter (such as T₁、T ₂Model and C₇、B ₁Parameter), just can be used in the daylight lamp fixture of all size of 7-40W.

Claims (4)

1, the electric ballast that has the kinds of protect circuit; once trigger to open by transistor bridge-type rectification circuit, filter circuit, fluorescent tube and wave control circuit, common emitter high-frequency electronic inverter circuit, kinds of protect circuit and shell and formed; it is characterized in that in the said common emitter high-frequency electronic inverter circuit oscillatory feedback inductance L ₁, L ₃With protective resistance R ₂, R ₄Be connected to oscillating tube T after the series connection respectively ₁And T ₂Base loop in; Said kinds of protect circuit comprise the work safety of electric ballast own, fluorescent tube lengthen the life the protection and the personal safety protection circuit;

2, as the said electric ballast of claim 1 with kinds of protect circuit; it is characterized in that the work safety protective circuit of described electric ballast own, be included in and meet fuse BX, RO in the current rectifying and wave filtering circuit, in the high-frequency electronic inverter circuit, be connected to protective resistance R ₁, R ₅, R ₂, R ₄

3, as the said electric ballast of claim 1 with kinds of protect circuit, it is characterized in that the described fluorescent tube protective circuit of lengthening the life, be meant at the tube filament two ends to be connected to diode D ₄, D ₅

4, as the said electric ballast of claim 1 with kinds of protect circuit; it is characterized in that described personal safety protective circuit; be made up of " output open circuit protective circuit ", this protective circuit is from going here and there the secondary sampling of the B in output loop, by conversion control circuit D ₃, C ₅, BG ₂, BG ₁Control signal is added on T ₂Base-emitter-base bandgap grading between.