KR870002137B1 - Operating circuit of a discharge lamp - Google Patents

Abstract

In the invention employing OTL type magnetic feedback, a voltage doubler and a bridge rectifier conect via a coil with 1st switch sect. and a pulse generator, whose output connecting to the bias input of 2nd switch sect. and to a coil of a magnetic oscillation trans T1. The 1st and 2nd switch sect.s connect in common to the trans. coil L4, its other end connecting to 1st switch's bias input. The input of an overvoltage detector connects to 2nd coil of a step- up trans., whose other end connects via 1st and 2nd overvoltage controls with base bias of 1st and 2nd switch sects.

Description

Free discharge lamp lighting circuit for 100V / 2200V combined use

1 is a circuit diagram of the present invention.

* Explanation of symbols for main parts of the drawings

A: Double voltage rectifier B: Bridge rectifier

C, d: 1st, 2nd switching part e, bar: 1st, 2nd overcurrent control part

G: Overvoltage detector H: Pulse generator

IC ₁ , IC ₂ : photocoupler T ₁ : self-oscillating transformer

T ₂ : Boost transformer FL: Discharge lamp

The present invention relates to a discharge lamp lighting circuit for a preload using a self-feedback circuit of the OTL method.

In general, the discharge lamp circuit has a disadvantage that the capacity of the discharge lamp is determined according to the capacity of the current-limiting coil. Therefore, a discharge lamp having a different capacity cannot be used except for the discharge lamp suitable for the capacity of the current-limiting coil of the corresponding discharge lamp lighting circuit. Since the discharge lamp is turned on by using the peak value of, the power factor of the discharge lamp lighting circuit is large due to the enormous power consumption during startup, unnecessary power consumption for a considerable time until the overvoltage of the discharge lamp is stabilized after startup, and power consumption during the maintenance of the discharge lamp lighting. And there was a problem that the efficiency is lowered, and since the discharge lamp is usually turned on at a phase voltage of a low frequency of 50Hz-60Hz, there was a drawback that there may be a visual impairment and hearing impairment due to the flicker phenomenon and the oscillation noise generated at this time.

In view of the above, the present invention provides an OTL-type discharge lamp lighting circuit using a switching transistor and a self-oscillating transformer, and turns on the discharge lamp at a high frequency output voltage of 30KHz-40KHz, thereby causing flicker phenomenon and oscillation noise. It is an object of the present invention to remove, and to maximize the use of power.

Referring to the configuration of the present invention by the accompanying drawings as follows.

In FIG. ₁ , a double voltage rectifier (a) consisting of a diode (D ₁ , D ₂ ), a capacitor (C ₁ , C ₂ ), or a bridge rectifier ( _b ) consisting of a bridge diode (D ₁₁ ) and a capacitor (C ₁₀ ) DC220V output terminal through transistor (TR ₁ ), diode (D ₂ , D ₃ , D ₁₀ ), capacitor (C ₃ , C ₄ , C ₅ ) and resistor (R ₁₃ ) through high frequency suppression coil (L ₁ ) Of the pulse generator comprising a first switching unit ( _c ) and transistors (TR ₆ , TR ₇ ), resistors (R ₂ , R ₃ , R ₄ , R ₅ , R ₁₁ ) and a capacitor (C ₁₃ ). The pulse output terminal of the pulse generator (h) is connected to a power supply terminal, and a transistor (TR ₂ ), a diode (D ₄ , D ₅ , D ₆ ), a capacitor (C ₆ , C ₇ , C ₈ ) and a resistor (R). ₁₀ ) is connected to the bias input terminal of the second switching unit (D) and one end of the coil (L ₂ ) of the self-oscillating transformer (T ₁ ), each end of which is an output end of the first and second switching unit (D). the other end of the self-oscillation transformer (T ₁₎ coil (L ₄₎ in a first switching gongjeop (C) the discharge lamp (LL) of the bias input terminal, a magnetic oscillation transformer (T ₁₎ 1 the secondary coil (L ₅₎ of the other end of the step-up transformer (T ₂₎ of the coil (L ₃₎ and connected in parallel, the capacitor (C ₁₆ ) Are connected in series, and the diode D ₈ , the capacitor C ₁₅ , the diode D ₉ , the capacitor C ₁₄ , and the trigger voltage input terminal of the pulse generator (h) are connected in parallel.

In addition, the input terminal of the overvoltage latching part (g) composed of the transistor TR ₅ , the diode D ₇ , the resistors R ₈ , R ₉ , R ₁₂ , and the capacitor C _{17 is} connected to ₂ of the boosting transformer T ₂ . an output terminal of connecting the primary winding (L _6), said over-voltage detector (G) are each photo-coupler (IC _1), the transistor (TR _3), and a photo-coupler (IC _2), the transistor of claim 1 consisting of (TR ₄₎ It is configured by connecting to the base bias stages of the first and second switching units (D, D), respectively, via the second overcurrent control unit (e, bar).

In the figure, reference numeral R ₇ denotes a resistor for starting current supply of the pulse generator (a).

Referring to the operation and effects of the present invention configured as described above are as follows.

DC 220V output voltage of the 100V input double voltage rectifying unit (A) or the 220V input bridge rectifying unit (B) of FIG. ₁ passes through the high frequency suppression coil L ₁ and the transistor TR ₁ of the first switching unit (C). Is applied to the collector and the collector and base of the transistors TR ₆ and TR ₇ of the pulse generator (a).

At this time, the voltage of DC 220V through the resistor R ₇ is connected to the discharge lamp FL in parallel with the capacitor C ₁₆ and the transistor TR ₇ of the pulse generating unit H through the resistor R ₆ . Since it is input to the gate, the initial start pulse is generated at the output terminal of the pulse generator (a).

In this way, since the start pulse voltage generated by the pulse generator (a) is input to the base of the switching transistor TR ₂ through the capacitor C ₈ of the second switching unit (d), the transistor TR ₂ is turned on. In addition, since the starting pulse voltage is applied to the coil L ₂ of the self-oscillating transformer T ₁ through the resistor R ₁₀ , the voltage induced in the coil L ₄ is the resistance of the first switching unit (C). The transistor TR ₁ is turned on by being input to the base of the transistor TR ₁ through the R ₁₃ and the capacitor C ₃ .

On the other hand, since the coils L ₂ and L ₄ of the self-oscillating transformer T ₁ are wound so as to be out of phase with each other, the base bias voltages of the transistors TR ₁ and TR ₂ have a constant phase difference. Switching transistors TR ₁ and TR ₂ as charge / discharge time constants of the capacitors C ₃ , resistors R ₁₃ , and capacitors C ₈ and R ₁₀ of the _first and second switch units (C, D). ), The high frequency output of 30KHz-40KHz appears.

Since the high frequency pulse voltage of 30KHz-40KHz is applied to the coil L ₃ of the self-oscillating transformer T ₁ , self oscillation is performed by the pulse voltage fed back to each coil L ₂ and L ₄ . .

At this time, the current flowing through the coil (L ₃ ) of the self-oscillating transformer (T ₁ ) is positively connected through a capacitor (C ₁₆ ) connected in parallel to the primary coil (L ₅ ) of the boost transformer (T ₂ ) and the discharge lamp (FL). Since the pulse component flows to the capacitor C ₁₅ and the diode D ₈ , and the sub pulse component flows to the capacitor C ₁₄ and the diode D ₇ , the primary coil L ₅ of the boosting transformer T ₂ . A very high AC pulse voltage is generated, and at this time, the tube voltage of the discharge lamp FL rises sharply to discharge the discharge lamp.

Once this way the discharge lamp (FL) is lit, the internal impedance of the discharge lamp is significantly reduced, because a pure resistance load, a resistance (R _6), a capacitor (C ₁₆₎ and a capacitor to the parallel circuit of the internal resistance of the discharge lamp (C _15, C ₁₄ ) and a series charge / discharge circuit to which the diodes D ₈ and D ₉ are connected are established, and the lighting of the discharge lamp is maintained by the oscillation output of the self-oscillating transformer T ₁ coil L ₃ .

Meanwhile, the voltage of the secondary coil L ₆ induced in proportion to the voltage between both ends of the primary coil L ₅ of the boost transformer T ₂ may have a different value depending on the load, that is, the capacity of the discharge lamp FL. The voltage is rectified by the diode D ₇ and the capacitor C ₁₇ of the overvoltage detector 4 and then applied to the base bias voltage of the transistor TR ₅ .

Therefore, when the voltage induced and rectified in the secondary coil L ₆ of the boost transformer T ₂ becomes equal to or greater than the bias voltage of the transistor TR ₅ determined by the resistors R ₉ and R ₁₂ , the transistor TR _{Since 5} ) is turned on, each of the photocouplers IC ₁ and IC ₂ and transistors TR ₃ and TR _{4 of the} overcurrent controller (e.g., bar) is operated.

Therefore, each base current of the switching transistors TR ₁ and TR _{2 of the first} and second switching units C and D is a diode D ₃ , D ₅ , a transistor TR ₃ , TR, and a diode D ₁₀ , D. ₆ ) and the feedback current is fed through each series circuit composed of the capacitors C ₃ and C ₈ , so that the base current of each switching transistor TR ₁ and TR ₂ is kept constant.

Therefore, since the base current of the switching transistor is automatically controlled as the capacity of the discharge lamp is changed, the oscillation output voltage induced in the coil L ₃ of the self-oscillation transformer T ₁ is a stable output voltage suitable for the capacity of the corresponding discharge lamp. It becomes.

On the other hand, the high frequency blocking coil (L ₁ ) is to prevent the high frequency pulse voltage of 30KHz-40KHz generated by the switching transistor (TR ₁ , TR ₂ ) to flow into the AC power input terminal.

The present invention provides a pre-lighting circuit of a discharge lamp using an OTL-type magnetic feedback circuit, and the oscillation noise in the discharge lamp is eliminated by turning on the discharge lamp with a high frequency output voltage of 30KHz-40KHz, which is higher than the audible frequency. The brightness of the is evenly (the quality of the light is improved), as well as having an unusual effect to maximize the power utilization.

Claims (1)

In the discharge lamp lighting circuit using the self-feedback of the OTL method, the coil L ₁ connected to the normal double voltage rectifying unit (A) and the bridge rectifying unit (B) is connected to the first switching unit (C) and the pulse generating unit (H). The output terminal of the pulse generator (a) is connected to the bias input terminal of the second switching unit (d) and one end of the coil (L ₂ ) of the self-oscillating transformer (T ₁ ), each end of which is first, 2 The other end of the self-oscillating transformer T ₁ and the coil L ₄ , which are in contact with the output end of the switching unit (C), the bias input terminal of the first switching unit (C), and the other end of the coil L ₃ is boosted. Trigger input terminals of the capacitors C ₁₄ and C ₁₅ and the pulse generator A through the primary coil L ₅ of the transformer T ₂ , the discharge lamp FL of the parallel connection, and the capacitor C ₁₆ in series. connection, and the input terminal of the voltage detection unit (G) has the step-up transformer (T ₂₎ 2 secondary coil (L _6), the output stage has first and second over-current control (e, F) via the first and second switching unit for ( Da, la) A 100 V / 220 V combined pre-discharge lamp lighting circuit, which is configured by being connected to a bias bias terminal.

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