SU1350851A1 - Device for stabilizing discharge of gas-discharge tube - Google Patents

Abstract

The invention relates to electrical engineering, in particular, to control gears for gas discharge lamps. The aim of the invention is to increase reliability and efficiency. The device contains a bridge inverter on controlled keys 1-4, a switching element 14, a control unit 18, and other elements. Due to the implementation of the switching element 14 symmetric, the introduction of an additional reverse diode 13 and a storage capacitor 16 in the device, some of the ballast functions of the filter choke 12 are combined. The lamp current envelope is created by discharging during the breaks of the network current of the precharged capacitor 16. Through key elements 1-4 of the inverter passes only part of the lamp current, which reduces their loading and loss. 4 il. with ate with "i u j with sd 00 ate

Description

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The invention relates to electrical engineering, in particular, to the control gear for the gas discharge lamp (GRL).

The purpose of the invention is to increase reliability and CODE.

Fig. 1 shows a diagram of a device for stabilizing the discharge of a GRL; in fig. 2 is a control block diagram; FIGS. 3 and 4 are time diagrams of currents and voltages.

The device contains a bridge inverter on controlled keys 1-4 (Fig. 1) with shunting diodes 5-8 to the output terminals of which are connected to a circuit of series-connected corrective throttle 9 and GRL 10, the first reverse diode 11, connected to the junction of the first cathode the output of the choke of the filter 12, the anode of the second reverse diode 13 and the switching element 14, the other output of which is connected to the terminal 15 for connecting the network, and the capacitor 16. The second output of the choke. The filter 12 and the second terminal 17 for connecting the network are connected to the output terminals of the bridge inverter, and the switching element 14 is implemented as an AC key.

The device also comprises a control unit 18 for controlling the operation of the control keys 1-4 of the bridge inverter and the switching element 14.

The control unit 18 (Fig. 2), the actuator .35 torus 16 - the return diode 11 - the choke

None in the form of a generator of 19 rectangular pulses, two blocks 20 and 21 of forming the pulse duration of the I-block 22 time shift carried out on the basis of the waiting multivibrators, the integrator 23, the lamp current sensor 24, the distributor 25 pulses, made on the basis of T-trigger - pa, and two blocks 26 and 27 match on the NAND gate 28-31.

At the same time, the output of the lamp current sensor 24 is connected via the integrator 23 with the control, the inputs of the waiting multivibrators of the pulses forming units 20 and 21, the output of the first of which is connected to the control input of the switching element 14, and the output of the second is connected to one of the inputs of the blocks 26 and 27 are coincident impulses, the second inputs of which are connected to the corresponding outputs of the distribution of 25 pulses, and the outputs of each of them are connected to

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20

25

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the control inputs of the corresponding switches 1-4 of the bridge inverter, the clock inputs of the first pulse shaping unit 20 and the pulse distributor 25 directly, and the second pulse shaping unit 21 through the time shift block 2.2 are connected to the output of the square pulse generator 19.

The device works as follows.

During the open state of the switching element 14 (time interval t, Fig. 3), the filter choke 12 connected in series is connected to the power supply voltage, a correcting choke 9 and GRL 10. At this stage the lamp current 1d is equal to the input current 1 „ ettj jv

with the supply voltage and inductance of the indicated chokes. P1ei reaching the level determined by the conditions for the creation of a sinusoid of its envelope, from the control unit 18 receives a signal to open the element 14 (time t, Fig. 3).

Starting from the moment t (until the moment tj, the energy stored in throttle x 9 and 12 returns to storage capacitor 16. At this stage, it is discharged through the following two circuits: filter throttle 12 - shunt diode 5 - condensate 12 of the filter; corrective choke 9 - GRL 10 - shunt diode .7 - capacitor 16 - shunt diode 6 - corrective choke 9.

In the interim

Chtj is the formation of the necessary / envelope current of the lamp 1d by discharging the storage capacitor 16 with the help of a bridge inverter; In the first

In the event that the current through the lamp 1d from the charged capacitor 16 flows along the circuit, the capacitor 16 - key 1 g correction throttle 9 - GRL 10 - key 4 - capacitor 16, and in the second

(shown in Fig. 3 by the dotted line) capacitor 16 - switch 3 - GRL 10 - correction throttle 9 - switch 2 - capacitor 16.

At the time point C, the bridge inverter's transistors are locked and the energy stored in the inductance 9 returns to the storage capacitor along the circuit: correction choke 9 - GRL 10 - shunt diode 7 - capacitor 16 - shunt diode 6 correction throttle 9, shunt diode 5 - capacitor 16 - shuntyyushy 1Y diode 8 - GRL 10 - choke 9 (in the second case).

Then follows the time interval tj.- tj, in which the processes occurring in the scheme are qualitatively similar to those considered earlier at stage t. After the return of the energy of the throttles 9 to the storage capacitor 16, the processes in the circuit for the positive half-wave of the supply voltage are repeated. For a negative half-wave pitka voltage, the processes in the device are similar to those considered.

The formation of the sinusoidal envelope of the input current i is carried out by introducing feedback (OS) at the average value of the current over its flow interval (t,) and selecting the appropriate transfer coefficients of the integrator 23 and the duration shaping unit 20. As a result, at the input of the key 14, a sequence of control pulses and, 4 (Fig. 3), is variable in duration.

FIG. Figure 3 also shows the sequences of control pulses U, and Uj, of the keys of the bridge inverter, with the help of which, at stages t and tg, the envelope current of the lamp 1d is formed. In the proposed device, it is also possible to control the current envelope of the lamp 1d with sinusoidal input current 1 (FIG. 4) The current envelope of the lamp is controlled by varying the amplitude and duration of the discharge current of the storage capacitor 16, which is achieved by varying the duration of the control pulses U and U, jj ( Fig. 4) arriving at the keys 1, 4 and 2, 3 of the bridge inverter, by introducing an additional OS over the average value of the current 1d in the interval of its flow tj. It is evident that the signal from the current sensor 24, integrated by the integrator 23, affects the time circuit of the waiting multivibrator of the duration shaping unit 21.

In this case, the optimum envelope current of the lamp should be considered as such that the pulsation coefficient of the luminous flux does not exceed the specified values. FIG. 4 shows an example of such an envelope, where, by inserting the OS, the average value of the current of the lamp 1d is maintained at a constant level.

Due to the implementation of the switching element symmetric introduction of an additional reverse diode and a storage capacitor in the device combines part of the ballast functions of the choke of the network filter. The necessary current envelope of the lamp is created by discharging during the pauses of the mains current of the precharged capacitor. In this case, only a part of the lamp current passes through the key elements of the inverter, which reduces their loading and losses, and consequently, increases the reliability of the device efficiency.

Claims (1)

Invention Formula A device for stabilizing the discharge of a gas discharge lamp, comprising a bridge inverter on controlled keys with shunt diodes, the output terminals of which are connected to the terminals for connecting the gas discharge lamp, the first reverse diode, the cathode connected to the combined terminals of the filter throttles and the switching element, another output which is connected to one of the terminals for connecting the network, another terminal for connecting the network, while the anode of the first reverse diode is connected to that input of the bridge inverter to which The anodes of its shunt diodes are connected, the control unit, the operation of the switching element and the keys of the bridge inverter, characterized in that, in order to increase reliability and efficiency, a second reverse diode is inserted, the anode of which is connected to the cathode of the first reverse diode, and the cathode with a different input terminal a bridge inverter, a storage capacitor connected between the input terminals of the bridge inverter, a correction choke, through which the output terminals of the bridge inverter are connected to the leads for connecting a gas discharge lamp, The switching element is made in the form of an AC key, and the operation control unit switches the element and the keys of the bridge inverter in the form of a square pulse generator, two pulse width shaping units, a time shift block, an integrator, a lamp current sensor, a pulse distributor and two matching blocks, the output of the current sensor of the lamp is connected via an integrator with the control inputs of the pulse duration shaping units, the output of the first of which is connected with the control input of the cross connecting element, and the output of the second is connected to one from the outputs of the pulse matching unit, the second inputs of which are connected to the corresponding outputs of the pulse distributor, and the outputs of each of them are connected to the control inputs of the corresponding keys of the bridge inverter, the clock inputs of the first pulse shaping unit and the pulse distributor directly, and the second block forming pulse durations through time shift blocks are connected to the output of a square pulse generator. L 6 fjr If, % 1 П П П П П  P JL l l l l P P P P P P G1 l l l l l l  L BUT. t / and, and llib -PGPGPP GPPP P PPP P GP Jd. l Jl Jil Jl L H P P Editor A. Shishkin Compiled by L. Krasnov Tehred M. Morgental Order 5300/58 Edition 799 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 Jil Jl L P P t to Proofreader A. T sko