RU12320U1 - ELECTRONIC CONTROL UNIT - Google Patents

Abstract

An electronic ballast, a DC / DC converter connected to the output of the rectifier, an inverter connected to the output of the converter, an inverter control unit, to the control input of which a timing capacitor and an ignition unit are connected, comprising a reactor, the primary winding of which is connected to the inverter output, a dinistor and a storage a capacitor connected in series with the secondary winding of the said reactor, and two charging resistors, characterized in that it is up to it is additionally equipped with a discharge resistor connected in parallel to the storage capacitor of the ignition unit, a voltage sensor connected to the output of the rectifier, an additional time-setting capacitor and a power control unit containing a comparator, a pulse selector in duration and a trigger, while the comparator is connected to the output of the voltage sensor by its input, and output to the pulse selector input in duration, the trigger input is connected to the pulse selector output in duration, and the trigger output is connected with the control input of the inverter control unit through an additional time-setting capacitor, the inverter input through the charging resistors is connected to the storage capacitor of the ignition unit.

Description

ELECTRONIC CONTROL UNIT

The useful model belongs to the field of electrical engineering and is intended for ignition and power supply of a high frequency of high-pressure gas-discharge lighting lamps.

Known electronic ballasts containing, a rectifier connected to an AC power source and a half-bridge transistor inverter, the output of which is connected through an isolation capacitor and a current-limiting reactor to a discharge lamp. A start capacitor is connected between the terminals for connecting the lamp. / Berezin M.Yu., Remnev A.M. Electronic ballast for high pressure mercury lamp. - Lighting. 1998. N3. C.7 /.

The disadvantage of such devices is the low stability of the inverter output voltage and, accordingly, the output power, which reduces the lamp life. In addition, triggering at the resonant frequency is used, which leads to long 3-4-fold overcurrents of power semiconductor devices and reduces the reliability of the device.

Known electronic ballasts containing connected to the input terminals of the DC voltage Converter, the output of which is connected to a half-bridge transistor inverter. The inverter output through the ignition device is connected to the output terminals for connecting a discharge lamp. The ignition device is a reactor, to the secondary winding of which a storage capacitor is connected through a dynistor, the charge of which is made through charging resistors. / Power semiconductor devices. International Rectifier. Application book. Per, from English, ed. V.V. Tokareva. - Voronezh: Publishing house Elist. 1995.S..600 /. Control gears.

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thanks to the DC-voltage converter, they provide a high power factor, a low level of higher harmonic components in the consumed mains current and stabilization of the inverter supply voltage. The lamp is ignited by high-voltage pulses, which allows continuous operation with currents slightly differing from the rated lamp current.

The disadvantage of such devices is the low life of the lamp, for ignition and power supply of high frequency, which is intended to consider the ballast. In addition, the inverter circuit is asymmetrical, which doubles the amplitude of the high-frequency current pulses consumed by the inverter and, accordingly, increases the level of generated interference.

The technical problem solved by the utility model is to increase the lamp life by introducing a power control mode.

The objective is achieved by the fact that the electronic ballast device containing a DC voltage converter connected to the output of the rectifier, an inverter connected to the output of the aforementioned converter, an inverter control unit, to the control input of which a timing capacitor is connected, and an ignition unit containing a reactor whose primary winding is connected with the output of the inverter, a dynistor and a storage capacitor connected in series with the secondary winding of the said reactor, and two charge the resistor, is additionally equipped with a discharge resistor connected in parallel to the storage capacitor of the ignition unit, a voltage sensor connected to the output of the rectifier, an additional time-setting capacitor and a power control unit containing a comparator, a pulse selector in duration and a trigger, while the comparator is connected to the output of the voltage sensor by its input, and the output to the input of the pulse selector in duration, the trigger input is connected to

the output of the pulse selector in duration, and the trigger output is connected to the control input of the inverter control unit through an additional time-setting capacitor, the inverter input through charging resistors is connected to the storage capacitor of the ignition unit.

The essence of the utility model is illustrated by the drawing, which shows the electrical circuit of the ballast.

The electronic ballast device contains an AC power source 1, a rectifier 2 connected to it, at the output of which a DC-voltage converter 3 is connected. At the output of converter 3, an inverter 4 is turned on, made according to a half-bridge circuit on transistors 5.6 and isolation capacitors 7.8, and connected to its control unit 9 (see Power semiconductor devices. International Rectifier. Application book. Translated from English, Edited by V.V. Tokarev. - Voronezh: Publishing House Elist. 1995.p.600). At the control input of the control unit 9, time-varying capacitors 10.11 are connected. The output of the inverter 4 through the ignition unit 12 is connected to the lamp 13. The ignition unit 12 is made on the reactor 14, the primary winding of which is connected in series with the lamp 13, and the secondary winding through the dinistor 15 is connected to the storage capacitor 16. Charging resistors 17 are connected to the storage capacitor 16, 18, connected to the input of the inverter 4, the discharge resistor 19 is connected in parallel with the storage capacitor 16. The electronic ballast includes a power control unit 20, which contains a voltage sensor 21, the comparator 22, the pulse width selector 23, the trigger 24. The voltage sensor is connected to the input of the comparator 22, the output of which through the pulse width selector 23 is connected to the input of the trigger 24. The output of the trigger 24 is connected to the control 11 control input of the control unit 9 inverter 4 through a timing capacitor 11. The device operates as follows. After applying voltage

The power supply starts the converter 3 and the inverter 4. The converter 3 provides stabilization of the voltage at the input of the inverter 4. The inverter 4 is idling until the formation of a high-voltage ignition pulse. The packing capacitor 16 is charged through the resistors 17, 18 to the breakdown voltage of the dynistor 15. Upon reaching the breakdown voltage, the dynistor is unlocked 15. The capacitor 16 is discharged to the secondary winding of the reactor 14. A high-voltage pulse is generated on the secondary winding of the reactor 14, which is transmitted through the corresponding open transistor (5, or 6) is applied to the electrodes of the lamp 13. The lamp 13 is lit and goes into a low impedance state. A current begins to flow through it, determined by the resistance of the reactor 14 at the modulation frequency of the inverter 4 and the resistance of the lamp 13. When the device is turned on, the output of the trigger 24 is set to a low level voltage. In this case, the capacitor 11 is connected to the control input of the control unit 9 by the inverter 4 through the output key element of the trigger 24. The operating frequency of the inverter 4 is determined by the resistance of the resistor 16 and the total capacitance of the capacitors 17.18.

The transition to low power mode is carried out on command from an external device. The command is to briefly interrupt the supply AC voltage. The length of the pause may be, for example, a half-period of the supply voltage. In this case, a voltage pulse of the same duration is formed at the output of the comparator 22. Identification of the control action is performed by the selector 23 pulses in duration. If the pulse duration is in a predetermined range, an output is received from the output of the selector 23 to the input of the trigger 24. At the output of the trigger, a high level signal is set, which corresponds to the disconnection of the capacitor 11 from the control input of the control unit 9. The modulation frequency of the inverter 4 increases, and the resistance of the reactor

4

increasing. The lamp current decreases and, accordingly, the output power decreases.

The reverse transition to the rated power mode is carried out with a second command from an external device. In this case, the trigger 24 returns to its original state, the capacitor 11 is reconnected to the control input of the control unit 9, providing a decrease in the modulation frequency of the inverter. Lamp current and power increase to the nominal value.

The presence of the selector 23 of the pulse duration eliminates the false response of the power control device during power failures.

Claims (1)

An electronic ballast, a DC / DC converter connected to the output of the rectifier, an inverter connected to the output of the converter, an inverter control unit, to the control input of which a timing capacitor and an ignition unit are connected, comprising a reactor, the primary winding of which is connected to the inverter output, a dinistor and a storage a capacitor connected in series with the secondary winding of the said reactor, and two charging resistors, characterized in that it is up to it is additionally equipped with a discharge resistor connected in parallel to the storage capacitor of the ignition unit, a voltage sensor connected to the output of the rectifier, an additional time-setting capacitor and a power control unit containing a comparator, a pulse selector in duration and a trigger, while the comparator is connected to the output of the voltage sensor by its input, and output to the pulse selector input in duration, the trigger input is connected to the pulse selector output in duration, and the trigger output is connected with the control input of the inverter control unit through an additional time-setting capacitor, the inverter input is connected to the storage capacitor of the ignition unit through charging resistors.