RU547U1 - Device for powering a fluorescent lamp - Google Patents

Abstract

A device for supplying a fluorescent lamp, containing a transistor inverter with its power and control circuits, to the output of which is connected a circuit containing a choke, an isolation capacitor and a discharge gap of the fluorescent lamp, formed by the first terminals of the first and second electrodes of the fluorescent lamp, and a circuit is connected between the second terminals of the electrodes containing a resonant capacitor and a posistor, characterized in that the parameters of the posistor satisfy the conditions M = (0.9 - 3.0) * (N * T1 * Rpts / T2 * Re) (J / ° С), (T2 * M) (/ Rpts * I ^ 2) = (0.4-2) (° C ); (Rrts + 2Re) * I <0.7 * Uз; where M and N are the heat capacities of the posistor and electrode; T1 is the temperature of the electrodes at which ignition should be carried out, ° C; T2 is the transition temperature of the posistor from a low-resistance to a high-resistance state, ° С; Re is the average resistance of the electrodes in the temperature range from 0 to T1, Ohm; Rrts is the average resistance of the posistor in the temperature range from 0 to T2, Ohm; I is the output current, A; Uз - ignition voltage, V.

Description

The device relates to electrical engineering; e, in particular, to a ei: poHHb ivi CCD-regulating apparatus (ZPRA) for luminescent: lunch (LL) and

can be used in lighting systems

most of the well-known electronic starting-cutting ycTpoiCTs (see, for example, US Pat. No. 4459516 according to CL 315/209, FRG application J 362: UMN according to CL 05/41 41/29) do not take special measures to exclude the possibility of ignition M with whether the electrodes are not warm enough. According to 1; Because of this, the durability of M when applying these ballasts is: it seems that the 1st rule is lower than the potential, which is their disadvantage -.:.

Electronic ballasts are known in which special measures are provided to reduce the risk of ignition of LL with insufficiently heated electrodes (see, for example 4, A.S.SSSR 1403393 according to KL.N05V 41/24. Lighting technology 5, 0.7-8) by the use of an additional relay in time to / hA / - / - ///, // the zone is clear capacitors or by using a node in the EPRL for measuring the frequency, made on an additional transistor, transfer mount, and other elements. A common drawback of these ballasts is the relative syllable, and, consequently, the increased cost and reduced reliability.

Known electronic ballasts (patent EP OI56439BI - prototype), in which, d.1a. ensuring preliminary heating of the LL electrodes, parallel to p;:; 3p i: iiior.fy the resistor with positive temperature coefficient of resistance (posistor) is inserted into the gap and sequentially from the LL electric arc. At the same time, according to the solution, the heat capacity of the posistor (A1) and the current sensitivity of the LL (D) electrodes are related by the ratio:

 () AK 3);

where: Tj (° С) is the temperature of the LL electrodes at which it is desirable to ignite the LL;

That (° C) is the temperature at which the posistor changes from a low coma to a high state (basic tegscheraturs); (The initial temperature of the posistor and the LL electrodes is very vague; well), Despite its merits (simplicity of circuit implementations, the jiaiiiioe solution is not without drawbacks, namely: shtutye / t walsz;: I, imposed by expression (I), do not exclude ignition LL with: .- 1е.; Just accurate heating of the electrodes, which is accompanied by destruction; -jX о: -: ol;.:. Of the left layer and a decrease in the durability of LL. The purpose of this is to optimize the ignition mode of LL. This goal is achieved by device for pltziya Lee containing a transistor inverter with its circuits power supply and control, the output of which is connected to a circuit containing a choke, an isolation capacitor and a discharge gap LL formed by the first outputs of the first and second electrodes II, between the second terminals of the ® -first and second electrodes is connected a circuit containing a resonant microchip resistor and a posistor, the properties and the parameters of the posistor are selected;: from the conditions / 1 / - Ti - Rpr A1. (0.9.0) (2) G2A-d. (KfTC J (RPT - o / 5r / 7 where: y is the output current of the transistor inverter ( de osstvuyu.ee chtchenie); and - LL ignition voltage at an electric locomotive temperature less than Tj. The joint fulfillment of conditions (2) - (4) ensures optimization of the ignition capacity of LL due to the fact that for different types of LL with different operating currents, the use of a posistor with an angle of azole: howling the properties of gli ensures: 1) fast (in 1-2 seconds ) heating of the electrodes of L. Ya to the tag "sheratury, in which the ignition of an electric discharge is not accompanied: act. destruction of the oxide layer of the cathodes; 2) the difference of the potent electrons insufficient for ignition of the discharge in LL: - :: do the electrodes during the time of their heating, and the fast singing of this potential difference to and above the ignition voltage only after sufficient heating of the cathodes. It should be noted that the transition of the LL from the preheating mode to the ignition mode and the actual ignition of the AL occur with the inventive device very quickly (in less than 0.1 time), which, together with providing a preliminary preheating of the cathodes, practically eliminates the glow discharge phase, negatively ;; Yu i-a durability LL. /

Designations in figure 1

transistor inverter with control circuits;

inverter power unit;

throttle;

isolation capacitor;

5 - a luminescent lamp;

6- resonant capacitor;

7- posistor.

As an inverter I, a half-bridge trisistor inverter with a three-winding current transForshor in transistor control circuits and a start circuit made on a diistoric relaxation generator can be used. The preferred operating frequency of inBsrtor I is kHz.

As a power supply unit of the inverter 2 can be used in conjunction with an accumulator capacitor. If necessary, a knot; -,.

be supplemented by a radio noise filter, a harmonic filter of the network s; (or) voltage stabilizer.

The inductor 3 and the isolation capacitor 4 form a ballast circuit for LL 5 after operation, and together with the resonant capacitor b, the inductor 3 forms a circuit whose resonant frequency and quality factor are controlled by the resistor 7.

The claimed device operates as follows. Most likely, in the inverter I, self-oscillations are excited, which from its output through the inductor 3 and the capacitor 4 go to the first output of the first LL electrode 5. The output current of the inverter I flowing through the circuit, Blyakakti-ugs the first LL LL 5, 7 resistor with the bridging device b and the second electrode LL 5 connected in parallel, it is determined by the supply voltage of the inverter I and the impedance of the inductor 3 and capacitor 4. This current heats the LL electrodes 5 and the posistor 7 for a period of time, which determines, in conjunction with condition (3), the temperature of the resistor Tg, its heat capacity Tew / 1, osgfotivleniya RTB and output current inverter I U.

This time, during which the temperature of the posistor 7 reaches the value of Tg, should be, according to condition (3) 0, ok. At lower values of time, there is a risk of insufficient heating of the oxide on LL 5 electrodes, and at high values of time at GLG: consumer properties of the lamp are written using this technical solution.

The fulfillment of condition (2) ensures the simultaneity of narpeiis from the effector 7 to the teg terature Tg and the LL electrodes 5 to the temperature Tm. When this value is large, the multiplier in front of the right side corresponds to bp-leo full heating of LL 5 electrodes.

- h - 6-

The fulfillment of condition (4) eliminates the risk of ignition of La 5 as long as the posistor 7 and LL electrodes 5 are heated.

After the temperature reaches 7 values, rzByasg :; T; /, its resistance increases sharply. For this reason, the voltage across the posistor 7 and, therefore, across the loose jLi circuit is extremely high: Due to resonance in the circuit formed by the inductor 3 and the capacitor 4 and b, the voltage across the discharge gap LL 5 can exceed the inverter power supply I, and provides reliable and fast s.p.

ttt with jiJi Oh.

Taking into account the preliminary heating of the LL 5 electrodes, it is fast; the r-st voltage on the LL 5 ensures the exclusion of destructive for Mei-i types of modes of half-wave and glow discharges.

In practice, the posistor 7 can be made, for example, .er, sooo; The prevailing image of alloyed titanium and barium with tesuraturs ;: TV limits 100 130 ° С. Resistance value for rose 1g-: 1st

LL types can range between 50-f500 ohms. Tep. 71 hedgehog: awn nc-3no 0 pa HELL is of the order of 0.2-10.05 j / ° C. Taking into account the need to reduce the heating by the posistor 7 of the other elements of the device, it is feasible to execute the posistor 7 with a mini-heat sink surface.

In order to improve the conditions of self-excitation of the inverter I, a capacitor having on the open can be connected with a posistor 7; frequency is less than the value

Authors: / 7p Volkov

A.F. Groysman

.A.N. Rabodzey .-- S.E. Shatalov

Claims (1)

A device for supplying a fluorescent lamp, containing a transistor inverter with its power and control circuits, to the output of which is connected a circuit containing a choke, an isolation capacitor and a discharge gap of the fluorescent lamp, formed by the first terminals of the first and second electrodes of the fluorescent lamp, and a circuit is connected between the second terminals of the electrodes containing a resonant capacitor and a posistor, characterized in that the parameters of the posistor satisfy the conditions M = (0.9 - 3.0) * (N * T1 * Rpts / T2 * Re) (J / ° С), (T2 * M) (/ Rpts * I ^ 2) = (0.4-2) (° C ); (Rrts + 2Re) * I <0.7 * Uз; where M and N are the heat capacities of the posistor and electrode; T1 is the temperature of the electrodes at which ignition should be carried out, ° C; T2 is the transition temperature of the posistor from a low-resistance to a high-resistance state, ° С; Re is the average resistance of the electrodes in the temperature range from 0 to T1, Ohm; Rrts is the average resistance of the posistor in the temperature range from 0 to T2, Ohm; I is the output current, A; Uз - ignition voltage, V.