CN2178038Y

CN2178038Y - Electronic ballast

Info

Publication number: CN2178038Y
Application number: CN 94200044
Authority: CN
Inventors: 马绪明; 马可
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-01-04
Filing date: 1994-01-04
Publication date: 1994-09-21
Anticipated expiration: 2004-01-04

Abstract

The utility model relates to a high power factor electronic ballast suitable for voltage boosting and current reducing of florescent lamps. The ballast comprises a ballast casing. A circuit board is arranged in the casing body. The circuit board is provided with a rectifying filter circuit, a passive power factor compensation circuit, a starting circuit, a vibrating and output load resonating circuit, a ballast inductance coil B1 and a starting capacitor C6. In a vibrating circuit, a main coil L1 and the starting capacitor C6 of a pulse transformer are connected in series, and a capacitor C7 and the coil L1 are connected in parallel. Both ends of the circuit composed of the coil L1, the starting capacitor C6 and the capacitor C7 are respectively connected to two filaments of a fluorescent lamp A. A resistor R1 is connected with the circuit of a filtering capacitor C1 in series, and a diode D1 and a capacitor C2 are connected with both ends of the resistor R1 in parallel.

Description

Electronic ballast

The utility model relates to a kind of electric ballast that is applicable to fluorescent lamp, is that a kind of boosting subtracts the stream high power factor electronic ballast.

The work of fluorescent lamp is after starting by means of starter, to keep the operate as normal that lamp tube current guarantees fluorescent lamp by ballast again.Electric ballast now commonly used, for example the electric ballast announced of Chinese patent CN2119072U include have in ballast housing, the housing current rectifying and wave filtering circuit is arranged on circuit board, the circuit board, excitation circuits for triggering, oscillator, ballast inductance coil and starting capacitor.This electric ballast is compared with single inductance type ballast has the high advantage of tangible power factor.At present commercially available electric ballast producer is a lot, the nearly hundreds of spare of patent applied for, and majority claims that all power factor reaches more than 80%, even bragging about of having reaches 95%.Only about 70%, yet power factor reaches the circuit of electronic ballast complexity more than 85% to the measured power factor of actual product, and cost improves.

The purpose of this utility model is not increase the complexity of circuit, can improve power factor, can prolong the useful life of fluorescent lamp and electric ballast again.

The scheme that the utility model electric ballast is realized is by changing the annexation of available circuit element, primary coil on the pulse transformer of oscillator is moved to fluorescent lamp starting capacitor circuit, it is connected with the fluorescent lamp starting capacitor, filter-capacitor circuit at power supply rectification filter circuit is connected in series a resistance, other again semiconductor diode and the electric capacity of connecing of its resistance.

The advantage of the utility model electric ballast is by increasing a little element, change vibration main coil wiring position, in the useful life that both can improve power factor and prolongation electric ballast and fluorescent lamp, can making electric ballast really reach purpose of energy saving again.

Accompanying drawing electronic ballast circuit figure of the present utility model

Below in conjunction with drawings and Examples the utility model electric ballast is described in detail.

The electric ballast of present embodiment includes to have in ballast housing, the housing current rectifying and wave filtering circuit, starting circuit, vibration and output load resonant circuit on circuit board, the circuit board, current rectifying and wave filtering circuit is the bridge rectifier of four diodes compositions and the filter circuit of capacitor C 1 and C2 composition.Only adopt the filter circuit of capacity cell C1, can make voltage waveform generation distortion in the line when capacitor C 1 charging, power factor reduces.For this reason, require the capacitance of capacitor C 1 the smaller the better, but require from fluorescent lamp and circuit working, the circuit ripple was big when capacity was too small, flicker or brightness shakiness can appear in fluorescent tube, electric capacity easily generates heat, the lamp current crest is than big, influence capacitor C 1 and fluorescent tube life-span, present embodiment has solved this problem, it is characterized in that: series connection one Passive Power compensating circuit on capacitor C 1, and its Passive Power compensating circuit is by resistance R 1, diode D1 and capacitor C 2 compose in parallel, the effect of resistance R 1 is the distortion that reduces the line voltage waveform, capacitor C 2 helps the filtering of high order harmonic component, when circuit working, when circuital current strengthens, when commutating voltage is lower than voltage on the capacitor C 1, the C1 both end voltage can be passed through diode D1 repid discharge, to supply with circuit working, the principle of promptly utilizing trickle charge to put soon, change mains waveform, to improve the power factor of line.

Rectification circuit is added on the starting circuit through filtered voltage; starting circuit is made up of resistance R 2, capacitor C 3, resistance R 3, protection diode D2, capacitor C 4 and diac D3; resistance R 2 is in parallel with capacitor C 3; resistance R 3 is in parallel with protection diode D2; connect the two ends of diac D3 link with the E point and the D point of circuit respectively (as figure) then with capacitor C 4.Vibration mainly is made up of triode BG1, BG2, capacitance C5, pulse transformer, ballast inductance coil B1 with output load resonant circuit.

Three winding L 1 are arranged on the pulse transformer; L2 and L3; winding L 1 around to winding L 3 around to identical; with winding L 2 around to opposite; L2; L3 respectively with R4; R5 is connected in series in BG1; the base circuit of BG2; resistance R 6; R7 is connected on BG1 respectively; the emitter base diode circuit of BG2; BG1; be connected to protection diode D4 between the base stage of BG2 and emitter respectively; D5; the end of ballast inductance coil B1 directly is connected on the output C point of oscillator; the other end links to each other with 1 joint of fluorescent lamp A filament; one of capacitor C 5 is terminated at the common ground point G point (or anode F point of power supply) of circuit; the other end of capacitor C 5 links to each other with filament 3 joints of fluorescent lamp A; of the present utility model being characterised in that: the winding L 1 on the pulse transformer is in parallel with capacitor C 7; back in parallel is in series with starting capacitor C6; the other end of capacitor C 6 is connected on filament 2 joints, and the other end after winding L 1 and capacitor C 7 are in parallel is connected on filament 4 joints of fluorescent lamp A.

During use, the pulsating voltage that the 220V alternating current of being come in by civil power obtains through the bridge rectifier rectification, through adding on diac D3 and the capacitor C 4 through resistance R 2, R3 again after the filter circuit filtering, when initial, triode BG1 is cut-off state, 310V voltage through two groups of filaments of resistance R 2, capacitor C 3, ballast inductance coil B1, fluorescent lamp and winding L 1 and capacitor C 7 to capacitor C 6, capacitor C 5 chargings, then charge to capacitor C 4 by resistance R 3 in another road, when being charged to the breakover voltage of diac D3, diac D3 conducting, thus make the BG1 conducting.At this moment capacitor C 5; the C6 end of charging already; because BG1 conducting; capacitor C 5; C6 discharges by BG1 by above-mentioned charge circuit again; because the positive feedback effect of pulse transformer; thereby make BG1 conducting more; BG2 further ends; because this process; carry out to avalanche type; very fast discharge process finishes; the effect of protection diode D2 is to aim at the discharge loop that C4 is provided with; in order to avoid also conducting simultaneously of BG1 during the BG2 conducting; make the BG1 false triggering again; crossing the certain hour after-current is tending towards reducing; on pulse transformer, respond to the electromotive force that the BG2 conducting BG1 that sends as an envoy to ends; and develop into the BG2 saturation conduction very soon; BG1 ends fully; finish series resonance one after another so again and again; because the filament of fluorescent lamp A is to be connected in the oscillating circuit; obtain preheating from filament; its resonance frequency is substantially by ballast inductance coil B1 and capacitor C 5; C6 decision (mainly by ballast inductance coil B1 and C6 decision); again because the inductance of ballast inductance coil B1 and the electric capacity of starting capacitor C6 meet the series resonance condition; thereby capacitor C 6 can obtain very high voltage; make fluorescent lamp A starter; filament 2 behind the fluorescent lamp A starter; 4 liang of point voltage substantially constants; do not change, because the negative resistance charactertistic of fluorescent tube (be that line voltage raises, voltage also slightly reduces between fluorescent lamp A two filaments) with line voltage; and the winding L 1 of pulse transformer and starting capacitor C6 are in series in the present embodiment, thereby electric ballast of the present utility model has to boost and subtracts the characteristic of stream.In addition, because fluorescent lamp A is under abnormality when not starting, the voltage between fluorescent lamp A two filaments raises, cause that thus oscillation intensity increases severely, make the electric current that flows through between fluorescent lamp A two filaments strengthen, last, always the fluorescent tube that does not start is burnt out, and ballast is excellent.

The several component parameters of present embodiment electric ballast are as follows: resistance R 1 is got 1.8K～2.4K(9W fluorescent lamp) or 390～560 Ω (40W fluorescent lamp): capacitor C 2 is got 0.047～0.1 μ F; Capacitor C 7 is got 0.1～0.4 μ F.D1 can be with run-of-the-mill rectifying tube preferably.

The advantage of the electric ballast of present embodiment is because fluorescent lamp A when working under abnormality; even fluorescent tube burns out, and ballast also is excellent, thereby electric ballast of the present utility model has self protective function; promptly need not to add any safeguard measure; also can play holding function, the power factor height is when supply voltage raises; the electric current of fluorescent lamp does not increase; electric current does not only increase when voltage increases again, reduces on the contrary, thereby makes the life-span of fluorescent tube increase.

Claims

1; a kind ofly be applicable to that boosting of fluorescent lamp subtracts the electric ballast that stream improves power factor; include ballast housing; circuit board is arranged in the housing; current rectifying and wave filtering circuit is arranged on the circuit board; the excitation circuits for triggering; oscillator; ballast inductance coil B1 and starting capacitor C6; the filter circuit of current rectifying and wave filtering circuit has filter capacitor C1; the output of filter circuit adds to the excitation circuits for triggering; the excitation circuits for triggering are by the resistance R 2 that is in series; R3; capacitor C 4; C3 in parallel with R2 and protection diode D2 and diac D3 form; the two ends of diac D3 respectively with resistance R 3; the intermediate contact of capacitor C 4 links to each other with the oscillator input; oscillator is by triode BG1; BG2; capacitor C 5; pulse transformer; ballast inductance coil B1 forms; three winding L 1 are arranged on the pulse transformer; L2 and L3; winding L 1 around to winding L 3 around to identical; with winding L 2 around to opposite; L2; L3 respectively with R4; R5 is connected in series in BG1; the base circuit of BG2; resistance R 6; R7 is connected on BG1 respectively; the emitter base diode circuit of BG2; BG1; be connected to protection diode D4 between the base stage of BG2 and emitter respectively; D5; the end of ballast inductance coil B1 directly is connected on the output C point of oscillator; the other end links to each other with (1) joint of fluorescent lamp A filament; one of capacitor C 5 is terminated at the common ground point G point of circuit; the other end of capacitor C 5 links to each other with filament (3) joint of fluorescent lamp A

Of the present utility model being characterised in that:

Winding L 1 on the pulse transformer is in parallel with capacitor C 7, and back in parallel is in series with starting capacitor C6, and the other end of electric capacity 6 is connected on filament (2) joint, and the other end after winding L 1 and capacitor C 7 are in parallel is connected on filament (4) joint of fluorescent lamp A; Series connection one Passive Power is mended circuit on capacitor C 1, and its Passive Power compensating circuit is composed in parallel by the cloudy R1 of electricity, diode D1 and capacitor C 2.