KR100396386B1 - Trigger circuit of gas discharge lamp - Google Patents

Abstract

The circuit has a bias stage connected between the positive and negative terminals of a rectifier bridge (D1,D2,D3,D4) coupled to the AC network, the bias stage including a filter circuit (C1,C2,C3,DR1,DR2) and a HF oscillator (R2-R6,T1,T2,D5,D6,C6,I1,I2). The inductive windings (I1,I2) of the HF oscillator are wound on a common core with a third inductance (I3,I4) to form a current transformer. A series current limiting circuit with an inductance (DR3,I4) and a capacitor (C8) is inserted in the current circuit between one terminal of the discharge lamp (FL) and the rectifier bridge.

Description

Trigger circuit of gas discharge lamp

The present invention includes a ballast between an anode and a cathode of a stop in an ac circuit network having a conductor and a neutral conductor, the ballast having a filter stage, an oscillation circuit and a high frequency resonant circuit, a decoupling capacitor, and a third winding. The three windings are wound on a common core together with the two windings of the high frequency resonant circuit to form a current transformer, and the ballast is configured to guide the gas discharge lamp from the connection terminal between the two transistors through the connection lead to one electrode of the discharge lamp. To a circuit for triggering.

Electrical ballasts for fluorescent lamps have been known for a long time. These ballasts cause the line voltage to rise from a typically 110 or 220-250V to a very high ignition voltage of about 1000V. It is also known that the frequency rises from a normal standard frequency of 50 or 60 Hz to a high frequency of 30 to 40 Hz. This measure has the advantage that the lamp can be ignited immediately upon switching on.

The current supplier, on the one hand, requires that the harmonics do not fall into the radio frequency range. This will occur if the frequency of the lamp supply voltage is 50 Hz and has a third harmonic of 150 Hz. Thus, the frequency must be less than 50 Hz but greater than 25 Hz for operation. On the other hand, reactive current is a big problem because it is difficult to measure and calculate.

Another problem is caused by the high frequency peak voltage, since the peak of the voltage overlaps the vibration of the line voltage. This problem is solved if the choke is inserted into the lead line according to DE 36 11 611. However, this has the disadvantage that the choke cannot be embedded in the stand of the current saving lamp because the choke must be relatively large at standard frequencies of 50-60 Hz. In order to reduce the harmonics, in Germany in particular 32 32 534, a direct connection circuit of a choke and a diode with two capacitors forms a wave divider at the junction of the two elements, which causes the transistor to be heavily loaded. Also, since the additional choke is part of the high frequency resonant circuit, it only partially cancels out the interference, so that the harmonics are higher than allowed, and in addition, the reactive current component cannot be reduced in this manner.

Accordingly, it is an object of the present invention to construct a circuit such that the reactive current component is almost zero and the voltage peak is suppressed on the lead side.

The object is to provide a series resonant circuit with an inductor and a capacitor in the current circuit for the purpose of limiting the current and for forming the voltage potential of the high frequency supply of the discharge lamp for the conducting connection of the diode in the rectifier according to the invention. This is achieved by providing between the terminals of the discharge lamps in the rectifier.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

In the circuit according to FIG. 1, power is supplied from an alternating current source AC to a line voltage of 220 V mil 50 to 60 kV via a terminal P as a conductor and a terminal 0 as a neutral conductor. A safety device (Si) protects the electronic circuit from high currents. Diodes D1, D2, and D4 are rectifier bridge circuits of known devices having chokes DR1 and current compensated filter chokes DR2 and compensation capacitors C1, C2, C3. To form. The electrolytic capacitor C5 is used as a smoothing capacitor.

The device for triggering the discharge lamp FL comprises a push-pull frequency generator with two transistors T1, T2 and return diodes D5, D6 as main components. do. The two transistors T1, T2 and the return diodes D5, D6, together with the resistor R6 and the capacitor C7, stabilize the high frequency resonant circuit. In this case, the capacitor affects the rising characteristics of the transistors T1 and T2. The transistor has resistors R2, R4 and emitter resistors R3, R5 connected in series for its operation. Coupling capacitor C4 is used to define the rising edge of the rectifier with diodes D1, D2, D3 and D4. The oscillation circuit consists of a first resistor R1, a capacitor C4, a diode D7, and a diac, and a base resistor R2 when the line voltage AC is connected to the terminals P and 0. The high-frequency resonant circuit having the first winding 11 to and the second winding 12 to the base resistor R4 is brought into a resonance state. The two windings 11 and 12 are wound on a common ring core.

The electrode E1 of the current saving discharge lamp FL is connected between the two transistors T1 and T2 via a connection lead VL having another choke DR3, the third winding I3 and the capacitor C8. It is connected to the connection point H of. The other electrode E2 is connected to the ground 0 of the AC voltage AC. The series resonant circuit consists of a resonant inductor of the choke DR2, a coupling capacitor C6, and a resonant capacitor C7. In this case, the resonant inductor DR2 and the coupling capacitor C6 are connected between the aforementioned connection point between the transistors T1 and T2 and the electrode E1 of the discharge lamp FL, and the resonant capacitor C7 is It is connected to the heating circuit of the discharge lamp FL. The manner of operation of a series resonant circuit for operating a push-pull frequency generator and a lamp is known on the one hand to the person skilled in the art and on the other hand the book "Elektronik-Schalt ungen", W. Hirschmann (Siemens Aktiengesellschalt), page 148. Since it is shown, it is not demonstrated here.

Two further diodes D8 and D9 are connected via a high frequency resonant circuit having transistors T1, T2 and return diodes D5, D6. The connection point of the two diodes (D8) and (D9) is connected to the connection point between the capacitors (C12, C13) connecting the two electrodes (E1) and (E2) of the discharge lamp (FL) through the temperature-dependent resistance (PTC). Connected. The arrangement causes preheating of the discharge lamp.

The resistance PCT at connection of the ballast is generally cold and therefore has a low ohmic resistance. In this switching state, the capacitor should have a relatively high capacitance, typically approximately 6 nF, in order to prevent the voltage between the electrodes E1 and E2 from occurring and the glow discharge in the discharge lamp. By the load circuit of the ballast, in this state, a current of about 100 mA flows through the spiral filaments of the electrodes E1 and E2 and the resistance PTC is heated to about 900 ° C. within a few seconds. This causes the resistor PTC to have a high ohmic resistance, whereby the voltage at the electrodes E1 and E2 rises to 1000 V, thereby causing the discharge lamp FL to ignite without glow discharge. In an ignited discharge lamp, the voltage drops to about 100V. In order to ensure that the resistance in the ignited discharge lamp does not continue to consume about 0.5 W of current, it is proposed to separate the current supply of the preheat circuit and the discharge lamp from each other. This is done by drawing the supply current of the discharge lamp from the connection point H. The ignition process is as described above, but in the discharge lamp ignited by the diodes D8 and D9, the current no longer flows through the resistor PTC and the resistance is cooled again. Therefore, unnecessary current consumption is avoided by the resistor PTC.

The circuit arrangement can also be used when a series circuit having an inductor I3 and a capacitor CB is connected to the connection lead VL between the connection point H and the electrode E1. As shown in FIG. 1, by feeding back the second electrode E2 to the rectifier, in front of the AC side rectifiers D1, D2, D3, and D4, the current is limited and the discharge lamp FL During the high frequency power supply of the power supply, a voltage potential is formed in the rectifier for the conductive connection of the diodes D1, D2, D3, and D4. Therefore, the peak of the high frequency voltage follows the sinusoidal vibration of the alternating current, and the voltage peak cannot overlap the alternating voltage.

This clearly shows that the operation of the discharge lamp can be significantly improved by the present invention. The circuitry does not increase much compared to the known circuitry because the inductor I3 is provided as an additional winding on the ring core with the windings I1 and I2, so that only one capacitor C8 This is because additionally necessary.

According to FIG. 2, a conventional current-saving discharge lamp having one and the same base including the electronic device according to FIG. 1 may be used at a small additional cost. For this purpose, it is proposed to provide four different taps to the choke DR3 and subdivide the inductor I3 of the series circuit into four partial windings I4a, I4b, I4c, and I4d. Of course, also in this case, four different capacitors C8a, C28b, C8c and C8d are required.

Another variant is shown in FIG. In this variant, since the choke is no longer present in the connection lead VL, it is not placed in the circuit for the electrode E1, but instead the choke DR5 is placed in the circuit of the electrode E2, that is, the rectifier D1. ), (D2), (D3), (D4) in the positive current path. The choke DR5 together with the additional choke DR6 forms a direct current supply for the high frequency generator. The electrode E2 is connected to the connection point of the two chokes DR5 and DR6. The operation is basically the same as described above, but here the charging of the rectifier diode takes place on the DC side in the rectifier.

Another short form is shown in FIG. A fourth choke DR4 is provided here in addition to the embodiment according to FIG. 1. The choke DR4 is connected to an AC lead wire between the terminals of the compensation capacitor C3 and the blocking capacitor C4. Thus, at the same cost, the ratio of effective power to apparent power is increased by more than 0.95 and the harmonics acting into the AC network are reduced to less than 10%. In laboratory tests, an ideal power factor of 99.5 was measured.

This is the action of the high frequency resonant current fed back to the AC voltage supply through the choke DR3, the capacitor C8 and the fluorescent lamp FL. The choke DR4 is oscillated by the resonance current. Therefore, the capacitor C4 is formed between the AC conductor O or P and the DC terminals of the rectifiers D1, D2, D3, and D4 together with the choke DR4 to form a unique oscillation oscillation circuit. The capacitor C4 may be omitted since the choke DR4 is oscillated by the high frequency current fed back through the lead VL. At the AC terminals, this vibration is likewise rectified at the rectifiers D1, D2, D3, and D4, causing modulation of the high frequency current by the standard frequency of the AC terminal, resulting in unwanted current peaks in the AC. Removed.

For the sake of certainty, FIG. 5 is basically configured as described above, but instead of full-wave rectification with four diodes, the voltage with diodes D10 and D11 connected with capacitors C2 and C3. Represent a voltage doubling circuit. The smoothing of direct current is made by two electrolytic capacitors (C4) and (C5), the electrolytic capacitors comprising a direct current output of diodes (D10) and (D11) and a phase lead of lead power supply (AC) ( Connected via P). The electrode E2 is naturally connected to the alternating current side. Here, too, since the high frequency voltage may reach only the height of the instantaneous amplitude of the AC voltage, there may be no or minimal distortion due to the wave vibration.

1 is a schematic diagram of a circuit for operating a current saving discharge lamp fed back from the discharge lamp to the lead side of the rectifier.

FIG. 2 is a circuit similar to FIG. 1 with a variant of the series oscillating circuit for operating discharge lamps of different power having the same ballast.

FIG. 3 is a circuit similar to FIG. 1 with terminals of an oscillation circuit having a discharge lamp and a second electrode on the direct current side in the series oscillation circuit.

FIG. 4 is a circuit similar to FIG. 1 with a device for defining the rising edge of the rectifier and a first electrode connected to the alternating current side.

5 is a circuit similar to that of FIG. 1 designed for a supply voltage of 110V.

Explanation of symbols on the main parts of the drawings

C1-C8: Capacitor D1-D9: Diode

DR1-DR4: Choke E1, E2: Electrode

FL: Discharge lamp I1, I2: Winding

T1, T2: Transistor VL: Connection Lead

Claims (7)

A ballast is provided between the positive and negative poles of the rectifiers D1-D4 connected to the alternating current network with the top conductor P and the ground conductor O, which stabilizes to charge the gas discharge lamp FL. High frequency resonant circuits R1-R5, T1, T2, C6, I1, I2 for switching capacitor C5, and output of the high frequency resonant circuits R1-R5, T1, T2, C6, I1, I2. As a circuit configuration for driving a gas discharge lamp in which the series resonant circuits DR3, I3, and C8 exist in the connection lead VL between (H) and the input of the rectifying means D1-D4, An additional choke DR4 is connected from the AC terminals O and P to the rectifying means D1-D4 and the blocking capacitor C4 at the AC lead, and the choke DR4 is connected via the blocking capacitor C4. It is connected to the high frequency resonant circuits R1-R5, T1, T2, C6, I1, I2 and is connected to the second electrode E2 of the gas discharge lamp FL through the compensation capacitor C3, and the choke DR4. ) Is excited to feed back through the connection lead (VL) and oscillate by the resonance current flowing through the electrode (E2) and the compensation capacitor (C3), and through the choke (DR4) charge path (D1-D4); A circuit arrangement for driving a gas discharge lamp, characterized in that DR4 and C4 are formed. A ballast between the anode and the cathode of the rectifying means (D1-D4) connected to an alternating current network having a phase conductor (P) and a neutral conductor (0), said ballast being smooth to charge the gas discharge lamp (FL) High frequency resonant circuits R1-R5, T1, T2, C6, I1, I2 for switching capacitor C5 and outputs of the high frequency resonant circuits R1-R5, T1, T2, C6, I1, I2 ( A circuit configuration for driving a gas discharge lamp provided with series resonant circuits I3 and C8 in the connection lead VL between H) and the input of the rectifying means D1-D4, The charging path has two series-connected chokes DR5 and DR6, the series connection being connected to the terminal of the second electrode E2 of the gas discharge lamp FL by the junction between the chokes DR5 and DR6. The choke serial connections DR5 and DR6 are connected to the outputs of the rectifying means D1 to D4, and the choke serial connections DR5 and DR6 are connected to the high frequency resonant circuits R1-R5, T1, T2, C6, It is connected to the output H of I1, I2, The said choke serial connection part DR5, DR6 is connected to the smoothing capacitor C5, The choke DR5, DR6 is connected to the diode D1-D4 from the high frequency DC side. ) Is configured to drive a gas discharge lamp. 2. The charging path of claim 1, wherein the charging path has two series-conducted diodes D5 and D6, and the series connection is made through the junction between the diodes D5 and D6. , T2, C6, 11, 12 are connected to the output H, each diode (D5, D6) of the high frequency resonant circuit (R1-R5-1-1, T2, C6, I1, I2) It is connected in anti-parallel to the emitter-collector junction of two transistors T1 and T2, and the diode series connection D5, D6 is connected to the output H and the series resonant circuit DR3, It is connected to the input of the said rectifying means D1-D4 via I3, C8, The said diode series connection part D5, D6 is connected in parallel with the smoothing capacitor C5, and the said diode D5, D6 is connected The smoothing capacitor C5 is charged by the addition of the high frequency voltage and the main voltage, and the rectification of the AC network low frequency at which the high frequency is superimposed is performed. A circuit configuration for driving a gas discharge lamp, characterized in that. The electrode E1 of the gas discharge lamp FL is connected to the inductance coils I3 and DR3 and the capacitor C8 of the series resonant circuits DR3, I3, and C8. It is connected to the output H of the high frequency resonant circuits R1-R5, T1, T2, C6, I1, I2, so that the gas discharge lamp FL is connected to the series resonant circuit DR3, through the connection lead VL. I3, C8), the circuit arrangement for driving a gas discharge lamp characterized in that the operation. 4. The gas discharge lamp FL according to claim 1 or 3, wherein the series resonant circuits DR3, I3, and C8 are directly connected to one of the current connection parts P and 0 through the connection leads VL. And a second electrode (E2) of () is directly connected to the current connection portion (P, 0). The inductance coil (I3) and capacitor (C8) of the series resonant circuit (DR3, I3, C8) are parallel branches (I3a, I3b, I3c, I3d, C8a, C8b, C8c, C8d). As configured and preferred, the connection of the gas discharge lamp FL to the first electrode E1 occurs in one of the branches for adapting the light efficiency of the gas discharge lamp FL. Circuit configuration to drive the lamp. The method according to claim 1 or 2, wherein two diodes (D8, D9) are connected in parallel to diodes (D5, D6) in a high frequency resonant circuit, the central tap of which is connected to the gas via a temperature-dependent resistor (PTC). And a preheating circuit connected to a junction portion of two capacitors (C12, C13) that crosses two electrodes (E1, E2) of the discharge lamp (FL).