SU1654990A1 - Lighting device - Google Patents

Abstract

The invention relates to electrical engineering and can be used in lighting installations for various purposes. The purpose of the invention is to simplify the design, increase the reliability and efficiency of the device. The invention makes it possible to reduce the heating current of the electrodes of the fluorescent lamp 1 by increasing the frequency of operation of the converter after ignition of the lamp, i.e. increase the load current of the converter; stabilize the lamp current. This is achieved by introducing transistors 17, 18, connecting the resistor 16 to the base-emitter junction of transistor 14 and using the cut-off voltage of the transistor 14 as a comparison device. To increase the reliability of the device, the output voltage of the converter must be lower than the cold ignition voltage, but more than the hot voltage of the fluorescent lamp. 1 il. I C /) f el F ce

Description

The invention relates to electrical engineering and can be used in lighting installations for various purposes.

The purpose of the invention is to simplify the design, increase the reliability and efficiency of the device.

The drawing shows a diagram of the lighting device.

The lighting device contains a fluorescent lamp 1, an inductive ballast 2, a two-phase transistor voltage converter, consisting of transistors 3 and 4, a transformer 5, a resistor 6 and diodes 7 and 8, two incandescent windings 9 and 10 of the voltage converter transformer 5 are connected to the corresponding successively connected throttles m 11 and 12 and to the filament electrodes of the fluorescent lamp 1, the secondary winding 13 of the transformer 5 through the inductive ballast 2 is connected to the fluorescent lamp 1, the third transistor 14, the connected em Tteroter With the first output 15 for connecting a power source, a resistor 16, included between the base and the emitter of the third transistor 14, two auxiliary transistors 17 and 18, whose collector-emitter transitions shunt the base-emitter transitions 3 and 4, respectively. , the bases of transistors 17 and 18 are connected to the collector of transistor .14, the base of which is connected to the midpoint of the primary winding 19 of transformer 5, the combined leads of transistors 3 and 4 are connected to the second terminal 2P for connecting a power source.

The device works as follows.

After connecting the push-pull voltage converter to the power supply, the amplitude of the current through the transistors 3 and 4 of the converter is limited by the level determined by the cut-off voltage of transistor 14 and the resistor 16 nominal. As soon as the instantaneous voltage across resistor 16 exceeds the cut-off voltage ba - a zo-emitter junction of the transistor 14, this transistor opens and turns on the transistors 17 and 13, turning off the transistors 3 and 4. The greater the load current, the higher the frequency of generation of the test voltage. At the output voltage of the converter

0

5 0 5 about 45, -Q 5

0

five

less than the voltage of the cold ignition, but more than the voltage of the hot ignition, at the initial moment the converter is loaded only on the electrodes of the fluorescent lamp 1. After the electrodes warm up, the fluorescent lamp 1 lights up, the load current of the voltage converter increases dramatically, which leads to an increase in the output voltage frequency converter and reducing the heating current of the electrodes of the fluorescent lamp 1 by increasing the resistance of the chokes 11 and 12, i.e. increase the efficiency of the device.

The introduction of control of the operation of transistors 3 and 4 of the voltage converter and the use of a resistor as a current sensor, and as a device for comparing the cut-off voltage of transistor 14, can simplify the design and increase the reliability of the device, stabilizing the lamp current.

Claims (1)

Invention Formula A lighting device containing a fluorescent lamp, inductive ballast, a transistor push-pull voltage converter, the two windings of the transformer of which are connected to the corresponding series-connected choke and filament electrode of the fluorescent lamp, and the secondary winding of the transformer is connected to one of the fluorescent lamp electrodes, the third a transistor connected by an emitter to a first terminal for connecting a power source; a resistor connected by a first terminal to The base of the third transistor, the second output for connecting the power source, characterized in that, in order to simplify the design, increase reliability and efficiency, two additional transistors are introduced, the collector-emitter junction of which shunts the corresponding base-emitter junction of both main transistors of the voltage converter, additional transistors are connected to the collector of the third transistor, the second output of the resistor is connected to the first output for connecting the power supply, and the first output of the resistor is connected en the middle of the primary winding transform- rgoodu ora preob516549906 voltage generator, free py-kinescent lamp, and the combined secondary water winding transformer leads transistors through inductive ballast the connected voltage is connected to the second inlet to another filament electrode for connecting the power source