CN2131269Y - Electronic transformer for neon lamp - Google Patents

Abstract

The utility model relates to a high-frequency high-voltage power supply which can be matched with various neon lamps, comprising a rectification circuit, a start-up circuit, a self-excited oscillation circuit, a constant-current shaping circuit and a high-voltage forming circuit. The utility model has a high power factor, low self wastage and constant-current constant-voltage characteristic, and thus when the voltage of the power supply of the utility model is varied, the utility model has small influence on the brightness of the neon lamp, and can realize the full-automatic protective function of the open circuit and the short circuit of a load, making up for insufficiency of the performance of the common dry type transformer of the neon lamp. The high-frequency high-voltage power supply can be matched with various neon lamps, can be served as a high-voltage power supply, and is applied to the technical fields of electrical engineering, medical care, measurement, etc.

Description

Electronic transformer for neon lamp

The utility model relates to the high-frequency and high-voltage power supply of a kind of and all kinds of neon light adapteds---neon sign electron transformer.

Common neon light system is made up of the very high dry type induction step-up transformer of the neon light tube of some and transformation ratio.This high voltage is generally all at the 13-17 kilovolt, and neon light produces glow discharge and lights under this action of high voltage.Because work frequency is low, and is very poor to the activation capability of electrode and gas, so requirement must have very high voltage just can light, and consumes more electric energy.Like this, require transformer that harder external characteristic must be arranged.In addition because step-up ratio too high (generally more than 60 to 70), so the high pressure of output is responsive especially to the fluctuation of line voltage, the brightness that directly influences neon light with light.Be in operation, the equivalent inductance of primary coil makes the power factor of transformer extremely low (about about 0.3) greatly.Produce this kind transformer except that consuming a large amount of non-ferrous metal and problems such as special steel material and High-Voltage Insulation, its use has also brought great idle burden to electrical network.

The purpose of this utility model is that a kind of neon light that makes of design is lighted easily, brightness stability, and have lower loss, and higher power factor, open circuit short circuit global function is protected safe and reliable gas tube sign transformer automatically.

The utility model comprises rectification circuit, start-up circuit, self-maintained circuit, constant current shaping circuit and booster circuit; The bridge rectifier that connects civil power is via resistance R _1-2, capacitor C ₃And diac D ₅The start-up circuit that constitutes is to the switch triode T of self-maintained circuit ₁Emitter and T ₂Base stage; Self-maintained circuit is by switch triode T ₁, T ₂Summation current transformer CT forms, the coil I head end of current transformer CT and switch triode T ₁Base stage is joined, and the coil II tail end of current transformer CT connects T ₂Base stage, current transformer CT coil III head end and T ₁Emitter, T ₂Collector electrode and CT coil I tail end join; Current transformer CT coil III tail end connects step-up transformer TP primary coil L I one end of constant current shaping circuit, the capacitor C of another termination two series connection of primary coil L I ₁, C ₂Mid point, two capacitor C after the series connection ₁, C ₂And receive switch triode T ₁Collector electrode and T ₂Emitter, the step-up transformer TP secondary coil L II two ends of high-pressure forming circuit are to the high pressure lead-out terminal; Said step-up transformer TP iron core is a square shape manganese Gan oxygen soft magnetic bodies, and primary coil L I and secondary coil L II are wound into the both sides of square shape magnetic core respectively.

The utlity model has higher power factor, lower own loss and constant current stabilized voltage characteristic.Therefore when mains voltage variations, less to the influence of neon light brightness, can realize the full-automatic defencive function of load open circuit, short circuit having remedied the deficiency of dry type gas tube sign transformer on performance of using always.It not only can with all kinds of neon light adapteds, also can be used as high voltage source and use, be applied to technical fields such as electrician, medical treatment, measurement.

Accompanying drawing is circuit theory diagrams of the present utility model.

Further describe below in conjunction with accompanying drawing: industrial-frequency alternating current or corresponding direct current (below omit corresponding direct current) are added to by D through power supply terminal and fuse RD ₁-D ₄The bridge rectifier of forming carries out full-wave rectification.Direct voltage after the rectification is added in by R ₁, R ₂, C ₃, D ₅On the start-up circuit of forming, C ₃Through R ₁Begin charging.Work as C ₃Last terminal voltage rise to D ₅Trigger value the time, D ₅Conducting also adds to switch transistor T to this voltage ₂Base stage, T ₂Saturation conduction, the A point is a zero level.The direct current anode passes through C ₁, transformer T _PPrimary coil L I, the coil III of current transformer CT, switch transistor T ₂Conducting over the ground, C ₁Charging, C ₂T is finished in discharge ₂Startup open-minded.T ₂Start when opening electric current and flowing through the coil III of CT, the coil I induces voltage negative just down on one, and this voltage is enough to make T ₁Saturation conduction, the coil II induces one and goes up negative positive voltage down simultaneously, and this voltage is enough to make T ₂Close dead.CT is here by mutual inductance effect between the coil I, II, III, played that conduction pipe is closed is dead, closed the effect of dead conducting, cooperates switch transistor T ₁, T ₂The common self-maintained circuit of forming.T ₁Conducting T ₂Close after death, the direct current anode passes through T ₁, coil III, transformer L ₁, C ₂Conducting over the ground, the A point is a high level, C ₂Charging C ₁A cycle of oscillation is finished in discharge.(T ₂During conducting, the A point is a zero level, C ₁Charging, C ₂Discharge; T ₁During conducting, the A point is dc positive power voltage C ₂Charging, C ₁Discharge).In this cycle of oscillation, flow through T _PThe electric current of primary coil L I is just opposite, and this electric current at one by T _PPrimary inductance L I and C _1-2Flow through in the second order network that is composed in series, make the pulsating current sineization, formed the constant current shaping circuit.So T _PSecondary L ₂More satisfactory sine voltage output is arranged.As long as booster circuit---be step-up transformer T _POne suitable transformation ratio is arranged, T _PSecondary L II high-frequency and high-voltage sinusoidal ac output can be arranged, to satisfy the needs of load.

The defencive function of load open circuit short circuit utilizes circuit self structure characteristics to finish: when load open circuit, and T _PThe primary coil equivalent inductance very big, L ₁Equiva lent impedance also very big, make T ₂Startup to open electric current minimum, the induced voltage in I, II is also extremely low and be not enough to promote T like this ₁, T ₂Conducting or close, and can not form vibration, T like this _PSecondary coil L ₂Just there is not voltage output yet.When load short circuits, be equivalent to T _PSecondary coil L ₂Short circuit, impedance are zero, promptly are equivalent to T _PPrimary coil L I for straight-through, its inductance is zero, itself and C ₁, C ₂Form second-order circuit, its timeconstant=2 π LC formulas, because of L → 0, and τ → 0 is so can not produce vibration.So T _PSecondary coil L ₂Do not have voltage output yet, played the automatic protective effect of short circuit.Must suitably determine L I and C ₁, C ₂Value just can guarantee out the reliable of short-circuit protection function.

The number of primary turns of said step-up transformer TP is 50-300, and the secondary coil L II number of turn is 2000-6000; The inductance value of current transformer CT coil I is 0.04-0.12mH, and the inductance value of coil II is 0.04-0.12mH, and the inductance value of coil III is 0.02-0.1mH.

Claims (2)

1, a kind of neon sign electron transformer has step-up coil, it is characterized in that it comprises rectification circuit, start-up circuit, self-maintained circuit, constant current shaping circuit and booster circuit; The bridge rectifier that connects civil power is via resistance R _1-2, capacitor C ₃And diac D ₅The start-up circuit that constitutes is to the switch triode T of self-maintained circuit ₁Emitter and T ₂Base stage; Self-maintained circuit is by switch triode T ₁, T ₂Summation current transformer CT forms, the coil I head end of current transformer CT and switch triode T ₁Base stage is joined, and the coil II tail end of current transformer CT connects T ₂Base stage, current transformer CT coil III head end and T ₁Emitter, T ₂Collector electrode and CT coil I tail end join; Current transformer CT coil III tail end connects step-up transformer TP primary coil L I one end of constant current shaping circuit, the capacitor C of another termination two series connection of primary coil L I ₁, C ₂Mid point, two capacitor C after the series connection ₁, C ₂And receive switch triode T ₁Collector electrode and T ₂Emitter, the step-up transformer TP secondary coil L II two ends of high-pressure forming circuit are to the high pressure lead-out terminal; Said step-up transformer TP iron core is a square shape manganese Gan oxygen soft magnetic bodies, and primary coil L I and secondary coil L II are wound into the both sides of square shape magnetic core respectively.

2, according to the described neon sign electron transformer of claim 1, the number of primary turns that it is characterized in that said step-up transformer TP is 50-300, and the secondary coil L II number of turn is 2000-6000; The inductance value of current transformer CT coil I is 0.04-0.12mH, and the inductance value of coil II is 0.04-0.12mH, and the inductance value of coil III is 0.02-0.1mH.