RU145877U1 - DEVICE FOR IGNITION OF DISCHARGE LAMPS - Google Patents

Abstract

A device for igniting discharge lamps supplied directly from an alternating current main or through a current limiter, comprising a working capacitor charged via a current-limiting element and connected via a switching element parallel to the primary winding of a pulse transformer, through the secondary winding of which a discharge lamp is connected directly or through a current limiter to the network, characterized in that in parallel with the turns of the secondary part of the pulse transformer, an additional a capacitor with a capacitance determined from the condition: C (U / U) / 10 <C / K <C (U / U) where C is the capacitance of the additional capacitor; C is the capacitance of the working capacitor; U is the voltage amplitude of the network; U is the required amplitude high-voltage pulse on the secondary winding of the pulse transformer; K is a coefficient equal to the ratio of the number of turns of the secondary winding of the pulse transformer to the number of turns of the part of the secondary winding of the pulse transformer to which the auxiliary capacitor is connected, while the maximum voltage applied to the auxiliary condenser yell, K times smaller than U.

Description

The utility model relates to electrical engineering and can be used to ignite discharge lamps.

A device for igniting gas discharge lamps powered from an alternating current main through a current limiter comprising a working capacitor charged through a current-limiting element connected through a switching element parallel to the primary winding of a pulse transformer, the secondary winding of which is connected in series with the lamp, an additional capacitor is connected parallel to the secondary winding of the pulse transformer (RU No. 126249, IPC H05B 41/23, publ. March 20, 2012).

A disadvantage of the known solution is that as an additional capacitor, an expensive capacitor is used with an acceptable voltage greater than the amplitude of the high voltage pulse (more than 5000 V), which reduces the reliability of the device

The technical result consists in increasing the reliability of the device by using an additional capacitor with a lower permissible voltage.

The technical result is achieved in that the device, fed directly or through a current limiter from the AC mains, contains a working capacitor charged through a current-limiting element, connected via a switching element parallel to the primary winding of the pulse transformer, through the secondary winding of which a discharge lamp is connected directly or through a current limiter in network. Parallel to the part of the turns of the secondary winding of the pulse transformer, an additional capacitor is connected with a capacitance determined from the condition:

where: C is the capacitance of the additional capacitor;

C _P - capacity of the working capacitor;

U _With - the voltage amplitude of the network;

U _And - the required amplitude of the high voltage pulse on the secondary winding of the pulse transformer;

K is a coefficient equal to the ratio of the number of turns of the secondary winding of a pulse transformer to the number of turns of a part of the secondary winding of a pulse transformer to which an additional capacitor is connected,

wherein the maximum voltage applied to the auxiliary capacitor is K times less than U _AND .

In FIG. 1 shows a device including a working capacitor 1 connected through a switching element 2 (for example, a transistor, sidak) parallel to the primary winding of a pulse transformer 3. A circuit consisting of a series-connected secondary winding of a pulse transformer 3 and a discharge lamp 4 is connected directly or through current limiter 5. The shunt capacitor 6 is connected to the network through the current limiter 5. The working capacitor 1 is connected to the network through the current-limiting element 7 and the current limiter 5. Pa parallel to the part of the turns of the secondary winding of the pulse transformer 3, an additional capacitor 8 is connected, the capacity of which is determined from the condition:

where: C is the capacity of the additional capacitor 8;

C _P - capacity of the working capacitor 1;

U _With - the voltage amplitude of the network;

U _And - the required amplitude of the high voltage pulse on the secondary winding of the pulse transformer 3;

K is a coefficient equal to the ratio of the number of turns of the secondary winding of a pulse transformer 3 to the number of turns of a part of the secondary winding of a pulse transformer 3, to which an additional capacitor 8 is connected.

Due to the fact that the additional capacitor 8 is connected to the turns of the secondary winding of the pulse transformer 3, the maximum voltage applied to the additional capacitor 8 is K times less than U _AND .

The device operates as follows. A working capacitor 1 is charged through a current-limiting element 7. As soon as the voltage U on the capacitor 1 reaches a certain value (usually within 0.5-1 of the amplitude value of the mains voltage), the switching element 2 goes into a conducting state (usually for a time of 1-100 μs) . During this time, the working capacitor 1 is discharged through the primary winding of the pulse transformer 3, the secondary winding of which is connected in series with the discharge lamp 4 to the network directly or through a current limiter 5. The emf induced on the secondary winding provides a breakdown of the electrode gap of the discharge lamp 4. The shunt capacitor 6 protects the inductor from breakdown. Due to the energy stored in the auxiliary capacitor 8, connected in parallel to the turns of the secondary part of the pulse transformer 3, the discharge current of the capacitor 1 through the interelectrode gap reaches values sufficient for the gas discharge lamp 4 to reliably ignite. After the occurrence of an arc discharge in the discharge lamp 4, the device is turned off.

Compared with the known device, the proposed allows to increase the reliability of the device due to the use of an additional capacitor with a lower permissible voltage.

Claims (1)

A device for igniting discharge lamps supplied directly from an alternating current main or through a current limiter, comprising a working capacitor charged via a current-limiting element and connected via a switching element parallel to the primary winding of a pulse transformer, through the secondary winding of which a discharge lamp is connected directly or through a current limiter to the network, characterized in that in parallel with the turns of the secondary part of the pulse transformer, an additional capacitor with a capacitance determined from the condition: C _P (U _C ² / U _AND ² ) / 10 <C / K ² <C _P (U _C ² / U _AND ² ) where C is the capacitance of the additional capacitor; With _P is the capacity of the working capacitor; U _With - the voltage amplitude of the network; U _And - the required amplitude of the high voltage pulse on the secondary winding of the pulse transformer; K is a coefficient equal to the ratio of the number of turns of the secondary winding of a pulse transformer to the number of turns of a part of the secondary winding of a pulse transformer to which an additional capacitor is connected, wherein the maximum voltage applied to the auxiliary capacitor is K times less than U _AND .