CN2888792Y

CN2888792Y - Low-voltage energy-saving lamp

Info

Publication number: CN2888792Y
Application number: CNU200620032806XU
Authority: CN
Inventors: 樊霖
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-01-10
Filing date: 2006-01-10
Publication date: 2007-04-11
Anticipated expiration: 2016-01-10

Abstract

The utility model of a low pressure energy-saving lamp, which comprises a ballast filter circuit, a switch circuit, a resonance circuit and a lamp, all connected to the power. The output-terminal of the ballast filter circuit is connected with the input-terminal of the switch circuit; the resonance circuit consists of a first capacitance, a first winding of the transformer, a choking inductor and a second capacitance, wherein the first capacitance, the first winding of the transformer and the choking inductor are orderly connected in series between the first output-terminal and the second output-terminal of the switch circuit. The first capacitance is jointed to the lamp in parallel connection and one end of the second capacitance is connected to the ground while the other end of the second capacitance is connected to both the first winding of the transformer and the port of the choking inductor. Based on the setup of the choking inductor at the front end of the first winding of the transformer and the setup of the second capacitance, at the transient from the upper half period of the preheating stage to the under half period of the breakdown stage, discharge of the second capacitance can maintain the lamp potential on a certain level to make the lamp work under low impedance so as to reduce the power loss of the lamp and play a role in power compensation.

Description

Low-voltage energy-saving lamp

[technical field]

The utility model is about a kind of low-voltage energy-saving lamp.

[background technology]

See also Fig. 1, existing low-voltage energy-saving lamp comprises the ballast filter circuit, switching circuit, resonant circuit and fluorescent tube, this ballast filter circuit is used for the voltage of input is carried out ballast filtering, this switching circuit is used at resonance, following half period is selected different current channels respectively, this resonant circuit is used for starting of oscillation and makes fluorescent tube at resonance, following half period is carried out preheating respectively and is punctured conducting, the input termination power of this ballast filter circuit, the input of its output termination switching circuit, this resonant circuit comprise and are connected first of switching circuit in turn, capacitance C6 between second output, first capacitor C 8, the first coil L2-1 of choke induction L3 and transformer.But there is following shortcoming in this kind electricity-saving lamp: fluorescent tube is under the situation of cycle power supply, and its voltage and current can change, thereby causes fluorescent tube to extinguish automatically easily and can't start.

[utility model content]

The purpose of this utility model is to provide a kind of low-voltage energy-saving lamp with power back-off effect.

The purpose of this utility model is achieved in that this low-voltage energy-saving lamp comprises the ballast filter circuit that is connected with power supply, switching circuit, resonant circuit and fluorescent tube, the output of this ballast filter circuit is connected with the input of switching circuit, this resonant circuit comprises first electric capacity, first coil of transformer, the choke induction and second electric capacity, this first electric capacity, first coil of transformer and choke induction are in sequential series at first of switching circuit, between second output, and this first electric capacity is in parallel with fluorescent tube, first coil of second electric capacity, one termination transformer and the link of choke induction, its other end ground connection.

Described switching circuit comprises first, second triode, the collector electrode of this first triode connects the output of ballast filter circuit, its emitter connects the collector electrode of second triode, be parallel with second coil of diode and transformer between its base stage and the emitter, the grounded emitter of this second triode, the tertiary coil of parallel diode and transformer between its base stage and the emitter, the current collection of this first triode is first output of switching circuit very, and the emission of this first triode is second output of switching circuit very.

Described switching circuit also comprises resistance, starts electric capacity, diac and the 3rd diode, this resistance and startup capacitances in series are between the input and ground of ballast filter circuit, and its tie point all is connected with an end of diac and the anode of the 3rd diode, the other end of this diac is connected with the base stage of second triode, and the negative electrode of the 3rd diode is connected with the collector electrode of second triode.

Second, third coil of described transformer all is associated between the base stage and emitter of corresponding triode with resistance string.

Described second electric capacity is in parallel with a resistance.

Also be provided with capacitance between first output of described switching circuit and first electric capacity.

Described ballast filter circuit comprises filter capacitor and forms the bridge-type ballast by four diodes that one end of this filter capacitor is connected with the output of bridge-type ballast, its other end ground connection.

Compared with prior art, the utlity model has following advantage: the front end of first coil by choke induction being arranged on transformer and the setting of second electric capacity, the moment that fluorescent tube was changed to second cycle that punctures in first cycle by preheating, second capacitor discharge maintains on the certain level fluorescent tube current potential, make fluorescent tube can remain on work under the Low ESR, thereby reduced the power loss of fluorescent tube, played the effect of power back-off.

[description of drawings]

Fig. 1 is the circuit theory diagrams of existing low-voltage energy-saving lamp.

Fig. 2 is the circuit theory diagrams of the utility model low-voltage energy-saving lamp first execution mode.

Fig. 3 is the circuit theory diagrams of the utility model low-voltage energy-saving lamp second execution mode.

[embodiment]

See also figure Fig. 2, the utility model low-voltage electricity-saving lamp comprises the ballast filter circuit that is connected with power supply, switching circuit, resonant circuit and fluorescent tube, the output of this ballast filter circuit is connected with the input of switching circuit, this resonant circuit comprises first electric capacity, first coil of transformer, the choke induction and second electric capacity, this first electric capacity, first coil of transformer and choke induction are in sequential series at first of switching circuit, between second output, and this first electric capacity is in parallel with fluorescent tube, first coil of second electric capacity, one termination transformer and the link of choke induction, its other end ground connection.This ballast filter circuit is used for power supply input carrying out ballast and filtering, this switching circuit is used for selecting different current channels in the upper and lower half period of resonance, and this resonant circuit is used to produce resonance and controls the fluorescent tube preheating and puncture conducting in upper and lower half period respectively.

This ballast filter circuit comprises filter capacitor C2 and the bridge-type ballast of being made up of four diode D1, D2, D3, D4, the negative electrode of diode D1 links to each other with the negative electrode of diode D3, the anode of diode D1 links to each other with the negative electrode of diode D2, the plus earth of diode D2, the anode of diode D3 links to each other with the negative electrode of diode D4, the plus earth of diode D4, and the contact of diode D1, D2 is connected with positive source, and the contact of diode D3, D4 is connected with power cathode.The end ground connection of filter capacitor C2, its other end links to each other with the negative electrode of diode D1, D3.The negative electrode of this diode D1, D3 is the output of this ballast filter circuit.

This switching circuit comprises first, the second triode Q1, Q2, the collector electrode of this first triode Q1 connects the output of ballast filter circuit, its emitter connects the collector electrode of second triode, the second coil L2-2 of transformer connects back with resistance R 3 and diode D6 is connected in parallel between the base stage and emitter of the first triode Q1, the grounded emitter of this second triode Q2, the tertiary coil L2-3 of transformer connects back with resistance R 4 and diode D7 is connected in parallel between the base stage and emitter of the second triode Q2, and this is second years old, tertiary coil L2-2, the end of the same name of L2-3 is for negative, the current collection of this first triode Q1 is first output of switching circuit very, and the emission of this first triode Q1 is second output of switching circuit very.This switching circuit also comprises resistance R 1, starts capacitor C 4, diac DB3 and the 3rd diode D5, one end of this resistance R 1 is connected with the output of ballast filter circuit, its other end is connected with startup capacitor C 4, start the other end ground connection of capacitor C 4, and this startup capacitor C 4 all is connected with the end of diac DB3 and the anode of the 3rd diode D5 with the contact of resistance R 1, the other end of this diac DB3 is connected with the base stage of the second triode Q2, and the negative electrode of the 3rd diode D5 is connected with the collector electrode of the second triode Q2.In the present embodiment, the anode of diode D6 is connected with the emitter of the first triode Q1, and its negative electrode is connected with the base stage of the first triode Q1; The plus earth of diode D7, its negative electrode is connected with the base stage of the second triode Q2.

This resonant circuit comprises capacitance C6, first capacitor C 8, the first coil L2-1 and the choke induction L3 of transformer between the collector and emitter of the first triode Q1 in sequential series, and is parallel with second capacitor C 7 and resistance R 7 between the tie point of first coil L2-1 of this transformer and choke induction L3 and the ground.This fluorescent tube is in parallel with first capacitor C 8, it comprises the first filament LR1 and the second filament LR2, the end of this first filament LR1 is connected with capacitance C6, its other end is connected with an end of first capacitor C 8, the other end of this first capacitor C 8 is connected with the end of the second filament LR2, and the other end of this second filament LR2 is connected with the first coil L2-1 of transformer.

The operation principle of this low-voltage energy-saving lamp is as follows: when this low-voltage energy-saving lamp is powered to it by external power source, electric current flows through the ballast filter circuit and carries out the filtering of multiplication of voltage ballast under rated voltage, and electric current starts capacitor C 4 chargings through 1 pair of resistance R.(after the value of 28V～32V), diac DB3 produces avalanche effect and punctures conducting at once, and capacitor C 4 is discharged to the second triode Q2, and Q2 is subjected to the forward bias voltage electric current and conducting when capacitor C 4 voltages are raised to the breakover voltage of diac DB3.Produce current path a :+V after the Q2 conducting _DCThe first coil L2-1 of → capacitance C6 → filament LR1 → first capacitor C, 8 → filament LR2 → transformer → second capacitor C, 7 charging → choke induction L3 (being low-resistance energy storage state) → Q2 collector electrode → Q2 emitter → ground.This process i.e. this electricity-saving lamp is in the last half period of resonance, and this half period is used for the filament of fluorescent tube FL is carried out preheating.

When Q2 collector current direction transient change (di/dt): the first coil L2-1 of transformer gives second, tertiary coil L2-2, the two ends of L2-3 produce an induced electromotive force, polarity is first, second, tertiary coil L2-1, L2-2, the end of the same name of L2-3 is for negative, tertiary coil L2-3 is subjected to induced electromotive force to be low-potential state Q2 is ended, the second coil L2-2 is subjected to induced electromotive force to be high potential state and makes the Q1 conducting for drive current of base stage of the first triode Q1, start capacitor C 4 triggerings after diode D5 and second triode Q2 discharge make it under a low-potential state, therefore stoped triggering again diac DB3.It was subjected to the induction by current cumlative energy when choke induction was worked in the Q2 conducting.Current path is when the Q1 conducting :+V _DCThe emitter of the collector electrode of → triode Q1 → triode Q1 → choke induction L3 (inductance energy produces the high voltage stack and discharges) → second capacitor C, 7 discharges → the first coil L2-1 → filament LR2 → first capacitor C, 8 → filament LR1 → capacitance C6.Puncture conducting → capacitor C 6 by path first coil L2-1 → fluorescent tube FL in addition.First capacitor C 8 produces the LC series resonance with choke induction L3 simultaneously, and its self-excitation operating frequency reaches 25KHZ～100KHZ.This process i.e. this electricity-saving lamp is in the following half period of resonance, is the bright process of fluorescent tube FL breakdown potential.

See also Fig. 3, it is second embodiment of the present utility model, and the difference of itself and first embodiment is: the half-bridge ballast that this ballast filter circuit adopts.

Low AC power voltage supply generally can only obtain 1.4 times VDC direct voltage after ballast filtering.And having only 1/2 of VDC voltage through half-bridge driven Q1, Q2 collector electrode to emitter both end voltage, power saving fluorescent lamps is to work in the triode alternation switch state up and down, and choke induction L3 plays metering function in switch.The fluorescent tube FL of operating state has a constant impedance, so can produce corresponding light tube electric voltage VL and lamp current IL.Fluorescent tube is under the situation of cycle power supply, can be along with current potential and electric current change, once two ends supply power voltage and electric current fluorescent tube can self-gravitation can not satisfy the power saving fluorescent lamps condition of work time, cause fluorescent tube can't start work, by choke induction L3 being connected on the front end of the first coil L2-1 and the setting of second capacitor C 7, can address this problem.

The effect that choke induction L3 is connected on the front end of the first coil L2-1 and second capacitor C 7 is set is: when DB3 triggers the second triode Q2 conducting, lead ground (this process is that preheating filament is relatively being launched electronic material under the active state) by initial electric current to the emitter of triode Q2 of filament LR1, it is charging stored energys that this process is given second capacitor C 7; When the first triode Q1 conducting, the choke induction L3 and second capacitor C 7 release energy simultaneously, and the first coil L2-1 strengthened initial excitation induced current potential, play bigger booster action during to puncture fluorescent tube (gaseous discharge lamp all is a negative resistance charactertistic: impedance is similar to ∞ before having conducting) conducting, it plays the power of lamp tube compensating action when fluorescent tube enters operating state.The principle of these settings is: also give second capacitor C 7 chargings when the second triode Q2 gives power saving fluorescent lamps FL power supply, and the second triode Q2 turn-off transient current potential and electric current descend, the first triode Q1 does not open again that (power saving fluorescent lamps fluorescent tube pipe under the situation of the little electric current of electronegative potential presses the VL impedance that can raise to increase rapidly, it can cause to extinguishing when electric current and voltage can not guarantee that fluorescent tube is kept work), at this moment second capacitor C 7 begins discharge current potential dimension is continued on certain level, and at this moment fluorescent tube can remain on Low ESR under and work; Power under the fluorescent tube Low ESR again when the first triode Q1 conducting, reduced the power loss of fluorescent tube and triode naturally, triode is alternately in steady state operation.

The purpose of resistance R 7 is: when the fluorescent tube fracture of wire, choke induction L3 and second capacitor C 7 can be connected and can be made electronic component burn (resistance R 1, diac DB3 and 7 chargings of second capacitor C cause magnet ring induction starting of oscillation and drive triode switch work) for bypass resonance and useless power consumption, resistance R 7 be exactly when the fluorescent tube fracture of wire to the usefulness of capacitor C 7 leakage currents by its failure of oscillation, guarantee the safety of product.

Claims

1. low-voltage energy-saving lamp, comprise the ballast filter circuit that is connected with power supply, switching circuit, resonant circuit and fluorescent tube, the output of this ballast filter circuit is connected with the input of switching circuit, it is characterized in that: described resonant circuit comprises first electric capacity, first coil of transformer, the choke induction and second electric capacity, this first electric capacity, first coil of transformer and choke induction are in sequential series at first of switching circuit, between second output, and this first electric capacity is in parallel with fluorescent tube, first coil of second electric capacity, one termination transformer and the link of choke induction, its other end ground connection.

2. low-voltage energy-saving lamp as claimed in claim 1, it is characterized in that: described switching circuit comprises first, second triode, the collector electrode of this first triode connects the output of ballast filter circuit, its emitter connects the collector electrode of second triode, be parallel with second coil of diode and transformer between its base stage and the emitter, the grounded emitter of this second triode, the tertiary coil of parallel diode and transformer between its base stage and the emitter, the current collection of this first triode is first output of switching circuit very, and the emission of this first triode is second output of switching circuit very.

3. low-voltage energy-saving lamp as claimed in claim 2, it is characterized in that: described switching circuit also comprises resistance, starts electric capacity, diac and the 3rd diode, this resistance and startup capacitances in series are between the input and ground of ballast filter circuit, and its tie point all is connected with an end of diac and the anode of the 3rd diode, the other end of this diac is connected with the base stage of second triode, and the negative electrode of the 3rd diode is connected with the collector electrode of second triode.

4. low-voltage energy-saving lamp as claimed in claim 2 is characterized in that: second, third coil of described transformer all is associated between the base stage and emitter of corresponding triode with resistance string.

5. low-voltage energy-saving lamp as claimed in claim 1 is characterized in that: described second electric capacity is in parallel with a resistance.

6. low-voltage energy-saving lamp as claimed in claim 1 is characterized in that: also be provided with capacitance between first output of described switching circuit and first electric capacity.

7 low-voltage energy-saving lamps as claimed in claim 1 is characterized in that: described ballast filter circuit comprises filter capacitor and forms the bridge-type ballast by four diodes that one end of this filter capacitor is connected with the output of bridge-type ballast, its other end ground connection.