CN2192125Y

CN2192125Y - Preheating starting type electronic ballast

Info

Publication number: CN2192125Y
Application number: CN 94214325
Authority: CN
Inventors: 索玉升
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-06-20
Filing date: 1994-06-20
Publication date: 1995-03-15
Anticipated expiration: 2004-06-20

Abstract

The utility model relates to a preheating starting type electronic ballast, which realizes preheating, starting and illumining a lamp tube by controlling the rapid rise of the voltage of both ends of the lamp tube. That is when the voltage at an induction coil end rises upwards, an interior charging circuit in a voltage control circuit suppressed in double directions is firstly charged; a control transistor is conducted in virtue of the conduction of a voltage regulator diode; then a vice-transistor is properly conducted in advance to make a main transistor cut off in time for effectively controlling the energy provided for filament loads; when the lamp tube is suppressed to start, the rapidly rising high voltage at both ends preheats the lamp tube. The preheating starting type electronic ballast saves electric power, avoids filament being rapidly damaged, and prolongs the service life of the lamp tube.

Description

Preheating starting type electronic ballast

The utility model relates to a kind of fluorescent lamp annex, exactly, relates to a kind of electronic ballast for fluorescent lamp with preheat starting function.

Since electronic ballast came out, little because of its power consumption, temperature was low, starts advantages such as fast, has become the main flow of fluorescent lamp ballast.

Though at present the electric ballast that uses has plurality of advantages, its build-up of luminance that generally all is the high voltage that is excited with the higher-order of oscillation, high electric current trigger fluorescent tube is lighted.This oscillation circuit that utilizes promotes fluorescent tube two tube voltage pressure reduction rapidly, mode till lighting fluorescent tube, because it is enough to accumulate the high pressure of kilovolt at short notice, and in the moment of lighting fluorescent tube, this high pressure acts on the filament of fluorescent tube, makes filament under the situation that has little time to react, pure forcing owing to the two ends high pressure, make electronics rapidly from the filament sur-face peeling, fluorescent material in the indirect stroke fluorescent tube and luminous.So not only easily make filament damage (number of times of lighting a lamp reduction), simultaneously,, also can cause the undesired acceleration precipitation of fluorescent material in the fluorescent tube, thereby quicken the aging of fluorescent tube, impel the life-span of fluorescent tube to lower because of exciting in too high voltages down.

The purpose of this utility model provides a kind of preheat starting formula electric ballast that can improve above-mentioned electronic ballast defective.

The utility model includes a pulse protection circuit of the required power supply of generator, a power factor correction circuit and a filter rectifier; Circuits for triggering of generator start trigger signal; Avoid device to trigger later on a trigger protection circuit of trigger action again; The main transistor LC oscillating circuit of generator frequency of oscillation; Drive the opposite each other inferior utmost point induction coil of polarity, so that main transistor presents conducting constantly or end in difference, to keep a driving transformer of vibration; And a control is paid a transistorized conducting and whether is made main transistor present in good time switch motion, the unlikely too high voltage control circuit of terminal voltage when making the fluorescent tube starting; It is characterized in that: this voltage control circuit is made up of oxide-semiconductor control transistors, charge inside loop and bleeder resistance that diode, voltage stabilizing didoe and resistance capacitance constituted; Wherein the collector electrode of this oxide-semiconductor control transistors is connected with a pair transistorized base stage, makes the charge circuit photoelectric process that electric current can quicken and pair transistor base is connected in series of oxide-semiconductor control transistors conducting, pays a transistor conducting as early as possible thereby make; The charge inside loop is serially connected in the base stage of oxide-semiconductor control transistors, and is connected in series mutually with a diode, makes the charge inside loop saturated gradually and make oxide-semiconductor control transistors be off state in the persistent oscillation of inferior utmost point induction coil, thereby reaches the purpose of pipeline start up by preheating fluorescent tube.Above-mentioned voltage control circuit should and be paid between the transistorized base stage at secondary induction coil.The time constant that the charge circuit of this voltage control circuit inside sets is the required time of preheating fluorescent tube.

The utility model be utilize metal at high temperature easily ionization produce the physical characteristic of discharge process, effectively reduce the required voltage of fluorescent tube starting, realize pre-heated starting, make that filament is unlikely to discharge under too high voltages, thereby improve the defective of above-mentioned electric ballast.

Below in conjunction with drawings and Examples, further introduce the utility model.

Fig. 1 is that circuit theory of the present utility model is implemented illustration.

As shown in Figure 1, AC power SAC through pulse protective circuit 11, power factor correction circuit 12 and filter rectifier 13, handles power supply after being imported by R, S end, the burning voltage that generator is required, and its positive terminal is connected on transistor Q2 and the capacitor C 1.Circuits for triggering 14 are made up of resistance R 8 and capacitor C 3 in parallel, the bidirectional diode D5 and the R2 of serial connection, with the start trigger signal of generator.D6 is the trigger protection diode, prevents to trigger later triggering again, takes this to form the trigger protection circuit.The switch motion of main transistor Q1 and Q2 cooperates the inductance L 1 of its serial connection and capacitor C 1, C2, CF to form LC series connection oscillation circuit, so that the energy of fluorescent tube F to be provided.Wherein D1, D2, D3, D4 are and protect the corresponding crystal plumber to do used.Because of transformer T2 is opposite with the polarity of T3, and induction effect is arranged, make not conducting simultaneously of transistor Q2 and Q1 with T1; Promptly when the T2 terminal voltage was the vibration of positive half cycle, the transistor initial condition was the Q2 conducting, and to make Q4 be nonconducting state.But when reaching the forward bias voltage drop of Q4, pays the E4 charge circuit voltage that is connected in series with the Q4 base stage, transistor Q4 conducting, and main transistor Q2 then ends; In like manner, when T3 was the vibration of positive half cycle, the transistor initial condition was the Q1 conducting, and Q3 is a cut-off state, and under the effect of E3, makes Q3 and Q1 change state mutually; Wherein pay transistor Q3 and Q4 and be the control switch as main transistor Q1 and Q2, its two ends respectively have clamp diode (CLAMP DIODE) D7, D8 promptly to make its voltage.Charge circuit E1 and E2 improve circuit as the drive signal of Q1 and Q2, and R6, Q7 are connected in series with the base stage of transistor Q1, Q2 respectively.

In the foregoing circuit structure, voltage control circuit 16 is made up of oxide-semiconductor control transistors Q6, diode D10, voltage stabilizing didoe D12 and resistance R 51, R52, R1 and capacitor C 5.Behind electric power starting, when A point oscillating voltage is raise by positive half cycle electronegative potential, diode D10 conducting, the charge inside loop R51 that is connected in series with diode, C5 and R1 just begin charging, and when voltage stabilizing didoe D12 conducting, because of the forward bias voltage drop of the Q6 base stage and the radio utmost point makes transistor Q6 conducting, electric current makes the E4 accelerated charging via the Q6 collector electrode that links to each other, and owing to the effect of E4 makes a pair transistor Q4 shift to an earlier date conducting, Q2 just in time ends like this, takes this to suppress the rising of fluorescent tube energy, makes the unlikely height of scurrying unusually of ballast lamp tube ends voltage when lighting fluorescent tube, cause bad destructive high pressure, simultaneously, at voltage more slowly in the uphill process, by the electric current of the filament of flowing through, make fluorescent tube reach pre-heat effect, light required voltage of fluorescent tube and energy thereby reduce.After above-mentioned pre-heat effect reaches, because charge inside loop R51, C5 and R1 are gradually saturated in secondary induction coil T2 persistent oscillation, make oxide-semiconductor control transistors Q6 by and no longer work, this moment, lamp tube ends voltage was raise with regard to no longer being suppressed, simultaneously because filament preheating, will instantaneously light, the A point voltage also is the quite stable state, and fluorescent tube can not influenced and operate as normal by voltage control circuit.R1 also is the bleeder resistance of C5.

In like manner, voltage control circuit 17 also in due course machine control Q3 present conducting state, thereby Q1 ended and reach above-mentioned identical purpose.Therefore two circuit structures are symmetry, and function is suitable, so no longer describe in detail.Above-mentioned control circuit 16 and 17 is to tackle transistor Q3 and Q4 implementation two-way control simultaneously, and effect is better than monolateral control, also can adapt to the different fluorescent tubes of multiple different size, electrical characteristic, so its scope of application is wider.

In a word, the utility model is with voltage control circuit 16,17 are serially connected in secondary induction coil T2, between T3 and the transistorized base stage, when positive half cycle raises under the induction coil voltage, charge in the charge inside loop, and because of the effect of voltage stabilizing didoe, make the oxide-semiconductor control transistors conducting, promptly so that pay transistor Q3, Q4 does sth. in advance conducting and allows main transistor Q1, Q2 ends ahead of time, so that suppress the voltage that lamp tube ends is upwards climbed sharply, make fluorescent tube reach pre-heat effect, and be the charge inside loop R51 that is subjected in the voltage control circuit its warm-up time, the time constant TIMECONSTANT of C5 and R1 controls (be that the charge inside loop is gradually saturated, make transistor end).Because the preheating fluorescent tube can make the starting voltage of lighting fluorescent tube decrease, and can make filament no longer be subjected to impacting with high pressure and accelerated ageing like this when preheat starting, thereby the protection fluorescent tube prolongs its useful life.

Claims

1, a kind of preheat starting formula electric ballast.Include a pulse protection circuit of the required power supply of generator, a power factor correction circuit and a filter rectifier; Circuits for triggering of generator start trigger signal; Avoid device to trigger later on a trigger protection circuit of trigger action again; The main transistor LC oscillating circuit of generator frequency of oscillation; Drive the opposite each other inferior utmost point induction coil of polarity, so that main transistor presents conducting constantly or end in difference, to keep a driving transformer of vibration; And a control is paid a transistorized conducting and whether is made main transistor present in good time switch motion, the unlikely too high voltage control circuit of terminal voltage when making the fluorescent tube starting; It is characterized in that: this voltage control circuit is made up of oxide-semiconductor control transistors, charge inside loop and bleeder resistance that diode, voltage stabilizing didoe and resistance capacitance constituted; Wherein the collector electrode of this oxide-semiconductor control transistors is connected with a pair transistorized base stage, makes the electric loop charging process that electric current can quicken and pair transistor base is connected in series of oxide-semiconductor control transistors conducting, pays a transistor conducting as early as possible thereby make; The charge inside loop is serially connected in the base stage of oxide-semiconductor control transistors, and is connected in series mutually with a diode, makes the charge inside loop saturated gradually and make oxide-semiconductor control transistors be off state in the persistent oscillation of inferior utmost point induction coil, thereby reaches the purpose of pipeline start up by preheating fluorescent tube.

2, preheat starting formula electric ballast as claimed in claim 1 is characterized in that: above-mentioned voltage control circuit should and be paid between the transistorized base stage at secondary induction coil.

3, preheat starting formula electric ballast as claimed in claim 1 is characterized in that: the time constant that the charge circuit of this voltage control circuit inside sets is the required time of preheating fluorescent tube.