CN2059043U - Neon lamp power supply with overload protection - Google Patents

Abstract

The utility model relates to a power supply with overload protection for a neon lamp. The circuit of the utility model which is provided with an output terminal overload and a short protection circuit adopts high-frequency oscillation and a transformer with a ferrite core to boost voltage. The input power of the utility model which has small size, light weight, low cost and convenient installation can follow with the length of the lamp tube within a certain rang, causing energy saving to be reasonable and the effect to be conspicuous. Adopting the utility model which is easy to realize the program control, the tube of the neon lamp has soft light and color, vivid color, long service life and high efficiency of light.

Description

Neon lamp power supply with overload protection

The utility model is a kind of rainbow lamp power.

The prior art neon lamp power source generally has two kinds, leakage inductance formula iron core gas tube sign transformer and neon sign electron transformer.The former shortcoming is that power consumption is many, is generally about 450VA, and making needs great deal of steel and copper material, and the latter adopts the electronic circuit, produces tens kilo hertzs high frequency, is boosted by core transformers, supplies with neon light.Because of its design feature; the latter need take necessary maintenance measure to the high pressure output; though on December 23rd, 8 or seven was disclosed similar invention in the open patent of invention in China; but owing to only used " high pressure open-circuit-protection " device in power supply inside; and be to be connected in the high tension loop; therefore, exist certain defective.This device is high pressure to occur in the high-pressure side when utilizing load open circuit, this high pressure can puncture the space that is connected on high-tension side two contacts, form arc discharge, and utilize electrical discharge arc will be connected on the blowout of two contact middles, reach the purpose of cutoff high.This method is because of being connected to two discharge contacts in the high-pressure side, make the dielectric strength of high-voltage output circuit, destroyed to a certain extent, when the higher or inevitable ambient dust of air humidity increases to some extent, unnecessary face discharge and the corona of prolonging will be occurred in the high-pressure side.During the protective device action, arc discharge occurring, also is disadvantageous to power supply.This method, when changing the open circuit fuse, complicated operation, as very not careful, fuse is not in the arc of discharge contact, or is partial to a certain contact, the protective device reliability will be reduced, even directly destroy the complete machine performance.

Task of the present utility model is: utilize the existing electronic circuit of ripe electric daylight lamp ballast to change slightly; position at former load fluorescent lamp; replace with output boostering transformer; a more rational overload protecting circuit has been proposed on this basis; the residing scope of magnetic core net sectional area optimum ratio of output transformer and feedback transformer has been proposed simultaneously.

Overload protecting circuit of the present utility model is the low voltage side at whole power supply, guarantees the integrality of output High-Voltage Insulation, makes on high-tension side insulation property, is greatly improved.The fuse processing ease is changed in no arc discharge in the power supply.Blown fuse is reliable.The optimum ratio of the magnetic core net sectional area of output transformer and feedback transformer is in the scope that the utility model proposes, and the input power of power supply has the characteristics (within the specific limits) of following the tracks of fluorescent tube length, and it is more reasonable to make it work.

Fig. 1 is the block diagram of the utility model embodiment.

Fig. 2 is circuit theory diagrams, and dotted line goes out four frame segments.

Fig. 3 is another embodiment.

Fig. 4 is another embodiment.

The utility model comprises power circuit, overload protecting circuit, oscillating circuit and four part compositions of output transformer.

Power circuit is by rectifier diode D ₁～D ₄, fuse BX ₁, capacitor C ₁, resistance R ₁Form, the exchange conversion of importing is become direct current, for oscillating circuit provides power supply, we do circuit 1 to the power circuit note.In the oscillating circuit, C ₄Be High frequency filter, resistance R ₅, C ₅Be attempted by after being in series positive source Vc end and systematically between, resistance R ₆Be attempted by C ₅On, triode BG ₁Collector electrode be connected on power supply Vc end, emitter and triode BG ₂Collector electrode joins, BG ₂The emission collection receive systematically.Diode D ₇Positive pole and bidirectional diode D ₆Be connected on R ₅, C ₅Contact on, diode D ₇Negative pole receive BG ₁Emitter, bidirectional diode D ₆The other end be connected on BG ₂Base stage.By R ₅, C ₅, R ₆, D ₆The circuit of forming passes through D before oscillating circuit work ₆To BG ₂Base stage provides a narrow current impulse, makes the oscillating circuit starting of oscillation, after the circuit starting of oscillation, because D ₇Existence, close narrow current impulse automatically.Capacitor C ₆Be attempted by BG ₁Collector and emitter on, limiting AC spike protective transistor, capacitor C ₇With output transformer B ₂Primary coil L ₅, feedback transformer primary coil L ₃After being in series and at BG ₁Collection, penetrate between, C wherein ₇Meet BG ₁Collector electrode, L ₃Meet BG ₁Emitter, C ₇, L ₅, L ₃Form series resonance during work, oscillating current feeds back to BG by feedback transformer ₁And BG ₂Base stage, resistance R ₈With L ₄After the series connection again with R ₉Parallel connection is together and at BG ₁Base stage and emitter between, resistance R ₁₀With L ₂After the series connection again with R ₁₁Parallel connection is together and at BG ₂Between base stage and the emission, by regulating resistance R ₈, R ₉, R ₁₀, R ₁₁Resistance, can adjust the operating state of triode, make it work the best.Output transformer B ₂In L ₆For the high-voltage output line circle, pass through L ₆Provide voltage to load, we do circuit 2 to the oscillating circuit note.

Overload protecting circuit is by protecting silk BX ₂, resistance R ₃, R ₄, RX, capacitor C ₂, C ₃, controllable silicon SCR, diode D ₅, triode BG ₃, coil L ₁Form.BX ₂Be connected between circuit 1 and the circuit 2 the main circuit power supply anode.RX and C ₂Be connected on the negative terminal of main circuit power supply between circuit 1 and the circuit 2 after the parallel connection.C ₂Negative terminal connection circuit 1, R ₃At the anode tap of SCR, with the negative terminal that connects after SCR connects with power supply VC and circuit 1.Triode BG ₃Emitter and the control utmost point of SCR join base stage welding system ground, D ₅Positive pole meets L ₁, negative pole series connection R ₄After meet BG ₃Collector electrode, C ₃And at BG ₃Collector electrode and base stage between, L ₁Other end welding system ground.L ₁Be output transformer B ₂A secondary coil, L ₁, D ₅, R ₄, C ₃Power supply for protective circuit.We do circuit 3 to the protective circuit note.

Output transformer comprises a primary coil L ₅With two secondary coil L ₁, L ₆And the magnetic core composition, the major function of output transformer is to boost, by L ₆Neon light is supplied with in output, auxiliary winding L ₁, only export several tens volts of voltages supply protective circuits that lie prostrate.

The course of work of typical circuit is such: power connection, and current rectifying and wave filtering circuit becomes interchange into direct current, supply circuit 2, in the circuit 2, BG ₁, BG ₂For ending, power supply is through R ₅To C ₅C is worked as in charging ₅On voltage reach and be enough to make D ₆During conducting, D ₆To BG ₂Base stage is exported a short duration current, BG ₂Conducting, power supply is through B ₂In L ₅And B ₁In L ₃To C ₇Charging, charging current is at B ₁Two secondary winding L ₂, L ₄Induced current make BG ₂Saturation conduction, BG ₁More reliable ending is through of short duration charging, C ₇Charging current begin to reduce, at B ₁On L ₂, L ₄Induced current make BG ₂Move back saturated and transfer to and ending, and BG ₁Transfer conducting, BG to by ending ₁After the conducting, capacitor C ₇Pass through BG ₁, L ₃, L ₅Discharge, discharging current is at B ₁On induced current, make BG ₁Further saturation conduction, BG ₂Reliably end, when discharging current reduces gradually, because B ₁Coupling make BG ₁Become and end, BG ₂Conducting, so repeatedly.BG ₁, BG ₂Conducting is C in turn ₇Provide charging and discharging circuit, C ₇, L ₅, L ₃Form resonance, after circuit enters operate as normal, because D ₇Have an appointment half time of negative terminal be the current potential that is near systematically, make C ₅On voltage do not reach D ₆The value of conducting, D ₆No longer to triode BG ₂Narrow current impulse is provided, and output transformer is the load of above-mentioned oscillating circuit, secondary coil L ₆The number of turn far more than primary coil L ₅The number of turn, L ₆Output voltage be several kilovolts of high pressure, use for fluorescent tube.

L ₁Be another secondary winding of output transformer, its turn ratio L ₅Much less, this winding voltage is through D ₅, R ₄, C ₃Behind the rectifying and wave-filtering,, controllable silicon provides power supply for triggering the loop.With regard to regard to a kind of neon light pipe (all identical fluorescent tubes such as thickness, color, technology): L ₆On output voltage be proportional to fluorescent tube length within the specific limits, the input current of whole power supply is proportional to L within the specific limits ₆On output voltage, in other words, within the specific limits, the input current of the long more power supply of fluorescent tube is big more, fluorescent tube is long will to make L ₆Output voltage too high, too high output voltage can cause transformer B ₂Damage.Therefore, carry out certain restriction, according to above-mentioned principle, at (or wherein one on) series connection fuse BX on two major loops that circuit 1 neutralizing circuit 2 is connected to output voltage ₂With current sampling resistor RX, when output voltage surpasses the regulation safety value, flow through the electric current on the RX, also surpass certain value, make RX go up voltage and increase, and be enough to make BG ₃Conducting makes the controllable silicon SCR conducting that is triggered, because R ₃Value can be zero or less, so, flow through R ₃Just very big with the electric current of SCR, be enough to make fuse BX ₂The power supply of 1 pair of circuit 2 of circuit is cut off in fusing.

The ratio of the output transformer that the utility model adopts and the magnetic core effective area of feedback transformer is (12～25): 1.Has the performance that output is not afraid of short circuit, because of its input power increases (within the specific limits) with the increase of fluorescent tube length, so said " overload " is that fluorescent tube length has surpassed specific length, until endless (open circuit).

Current sampling resistor in the overload protecting circuit described in the utility model and circuit have multiple connection form, and the element composition of having nothing in common with each other, and Fig. 3, Fig. 4 are other two kinds of representative instances.Among Fig. 3, current sampling resistor is connected on the positive pole of circuit 1 and the Vc end of circuit 2, adopts bidirectional triode thyristor and PNP transistor BG ₃'.Has the same defencive function of the protective circuit shown in Fig. 2 of going the same way.Fig. 4 is with another transformer B ₃A kind of scheme as the power supply of circuits for triggering.Also have with the same function of protective circuit shown in the circuit diagram 2.

The element choosing value scope of the utility model exemplary embodiments is: BX ₁Be 2A, 250V.D ₁～D ₄Be 1A～3A/400V, BX ₂Be 0.5A～1A/250A.C ₁Be 47 microfarads～100 microfarads/450V, R ₁Be 470 kilo-ohms, R ₃Be 0～100 Europe, R ₅, R ₆, R ₇Be respectively 470 kilo-ohms, 390 kilo-ohms, 390 kilo-ohms, R ₈, R ₁₀Generally get 6.8～51 Europe, R ₉, R ₁₁Generally get 68 Europe, R ₄Get 100～200 Europe, the resistance of RX is in 1～8 Europe.C ₂, C ₃, C ₄, C ₅, C ₆, C ₇Get 100 microfarads, 4.7 microfarads, 0.1 microfarad/400V, 0.047 microfarad～0.1 microfarad, 4700 picofarads～0.01 microfarad/630V respectively.Controllable silicon is generally got 3A～15A/400V～600V.BG ₁, BG ₂Generally get high back-pressure large power triode such as BU ₂₀₈Deng, BG ₃Be 3DG ₁₂B or substitute model.D ₅With the higher diode of frequency.D ₆Be generally common bidirectional trigger diode.D ₇Be 1A/400V, the magnetic core of feedback transformer diameter 10 * 5 * 5(mm) ferrite beads, L ₂, L ₄Be 3～4 circles, L ₃Be 12～15 circles.Output transformer B ₂Magnetic core U ₁₆FERRITE CORE, L ₁Be 7～20 circles, L ₅Be 115～125 circles, L ₆Be 2500～2700 circles, wherein L ₆Require withstand voltagely more than 20,000 volts, thinner as line can be obtained directly at 0.09～0.15mm in line footpath, L ₆Two deliveries all should be unsettled over the ground, must not an end ground connection.When the overload protective circuit adopts the scheme of Fig. 3, Fig. 4, can be with reference to the Scheme Choice element of circuit diagram 2.

Power supply according to this typical circuit parameter is formed when load is diameter 10mm neon light tube cell, can make power supply drive 10 rice lamp pipe input powers about 80VA by regulating the value of RX.

Claims (4)

1, a kind of neon lamp power source that has overload protection is made up of power circuit, oscillating circuit, overload protecting circuit and output transformer, and operating frequency is 10KHZ and 70KHZ, and output transformer work magnetic bias is at 1,2 quadrants, and the vibration major loop is by capacitor C ₇, output transformer B ₂Elementary winding L ₅, feedback transformer B ₁Elementary winding L ₃And transistor BG ₁, BG ₂Form BG ₁, BG ₂Alternate conduction is C ₇, L ₅, L ₃The loop provides and discharges and recharges the vibration path, and it is characterized in that has the current sampling resistor that is serially connected in the main circuit power supply in the overload protecting circuit, and circuit is the dual transformer structure, and the ratio of the magnetic core net sectional area of output transformer and feedback transformer is (12～25): 1.

2, according to the described neon lamp power source of claim 1, it is characterized in that the overload protecting circuit sample resistance is to be connected in power circuit and the major loop that oscillating circuit is connected, the value of resistance in 1 Europe～100 Europe.

3, according to the described neon lamp power source of claim 1, it is characterized in that dual transformer is FERRITE CORE, the magnetic core effective cross-section of feedback transformer is: (8～20) square millimeter.

4,, it is characterized in that overload protecting circuit is by SCR and R according to the described neon lamp power source of claim 2 ₃Be attempted by the anode and the negative terminal of power supply after the series connection, BX ₂All be serially connected in rectifier power source and the major loop that oscillating circuit is connected with RX, RX is last and meet capacitor C ₂, BG ₃Emitter connect the SCR trigger electrode, base stage welding system ground, L ₁On induced voltage through D ₅, R ₄, C ₃Supply with BG behind the rectifying and wave-filtering ₃Collector electrode.

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