JPH02103900A - Lamp driving source - Google Patents

Abstract

PURPOSE:To make it possible to apply preheating current, lighting current and darkening current separately to a lamp respectively by connecting an inductor and a transformer in series to the filament of the lamp and providing a DC source section to superpose a variable DC current to the AC current flowed in the inductor. CONSTITUTION:When a switch SW is turned on, a filament current is flowed in the filament of a lamp 32, and the current is detected with an AC current detecting means 6 through a resistor 7, and a driving means 8 turns a transistor 9 on/off, then DC current is controlled by a variable DC source and the resultant inductance of the primary winding 21 and the inductor 13 is decreased, thus an AC current superposed with a definite DC current is flowed in the filament of the lamp 32 to preheat the filament. When the switch SW is turned off, the AC current is cut off and the AC voltage generated in the secondary winding 1c is applied between the both filaments of the lamp 32. Thereby the lamp 32 can be lighted by the applied starting voltage to flow a tube current in the lamp 32.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a lamp drive power source that drives a lamp by applying an alternating current power source.

(Prior Art) FIG. 3 is a circuit diagram illustrating an example of a conventional lamp driving power supply, and 31 is an AC power supply, which applies an AC current of, for example, 50/60) 1z between the filaments of the lamp 32, and 32 is turned on. 33 is an inductor, lamp 32
Limit the alternating current applied between the filaments. 3
4.35 is a capacitor that divides the AC current applied to each filament of the lamp 32 and generates a preheating current for the lamp 32. SW is a switch that is turned on during preheating and turned off when the lamp 32 is turned on.

When turning off the lamp 32, the voltage of the AC power source 31 is lowered and the power supply is cut off. As a result, the lamp 32 is turned off.

On the other hand, when preheating the lamp 32, the switch SW is turned on, the alternating current is limited by the inductor 33, and a preheating current for the filament is obtained by dividing the current between the filament of the lamp 32 and the capacitors 34 and 35.

Furthermore, when the lamp is turned off, the switch SW is turned off and the alternating current is applied to the lamp 32 as a tube current, thereby lighting the lamp 32.

[Problem to be solved by the invention]

In this way, in the conventional lamp drive power supply, the lamp 3
Current during preheating 2 When controlling the current during 1 lighting, the AC power supply 31 is connected to the inductor 33 and the capacitor 34, 35.
Therefore, there were problems such as the inability to control the current using part of the multi-output power supply.

This invention was made to solve the above-mentioned problems, and by varying the inductance of the inductor that connects the alternating current supplied to the lamp from the alternating current power source to the lamp circuit, it is possible to Turn off the lamp using the current.

The object of the present invention is to obtain a lamp driving power source that can individually apply one preheating current and one lighting current.

[Means to solve the problem]

The lamp driving power source according to the present invention connects an inductor and a transformer to the filament of the lamp.
A DC power supply unit that is connected to the series through the next winding and variably superimposes a DC current on the AC current generated by the inductor is installed through the secondary winding of the transformer, which has the same inductance as the inductor and has the opposite polarity. This is what I did.

[Effect]

In this invention, when an alternating current is applied to the filament of the lamp from a transformer power source and a direct current is applied from a direct current power source, the secondary winding of the transformer, which is wound with the same inductance as the inductor and with opposite polarity, The wire cancels the AC component and applies enough DC current to preheat the filament, controlling the lighting, preheating, and extinguishing of the lamp.

(Embodiment) FIG. 1 is a power supply circuit diagram illustrating the configuration of a lamp drive power source showing an embodiment of the present invention, and the same components as in FIG. 3 are given the same reference numerals.

In this figure, 1 is a transformer, which is composed of a primary winding 1a and secondary windings lb and Ic.The primary winding 1a includes a transistor 2 driven by an oscillator 3 and a DC power supply 11.
is connected to the secondary winding 1b, a diode 4 and a capacitor 5 are connected to the secondary winding 1b, and a rectified DC voltage is outputted to both ends.

The filament of the lamp 32 is connected to one end of the secondary winding 1c, and the inductor variable section 12 is connected to the other end.
A primary winding 21 of a transformer constituting the transformer is connected thereto.

Reference numeral 6 denotes an alternating current detection means for detecting an alternating current flowing through the resistor 7. The resistor 7 is connected to the inductor 13,
One end of the inductor 13 is connected to the primary winding 21 of the inductor variable section 12. Reference numeral 8 denotes a drive means that turns on/off a transistor 9 to vary the DC voltage from the DC power supply 10, and a secondary winding 22 having the same inductance as the inductor 13 and opposite polarity changes the inductance of the inductor 13. .

FIG. 2 is a circuit diagram illustrating the configuration of the inductor variable section 12 shown in FIG. 1, and the same components as in FIG. 1 are given the same reference numerals.

In this figure, 21 is a primary winding, which constitutes the inductor variable section 12 together with the secondary winding 22, and a transformer is installed between the open side of the primary winding 21 and the inductor 13, that is, between the terminals a and 1. An alternating current voltage Vi generated on the secondary winding 22 side is applied. One end of the secondary winding 22 and one end of the primary winding 21 are connected to the inductor 13, and the other end of the secondary winding 22 is connected to the variable DC power supply 25 via the resistor 24.
The other end of the secondary winding 21 is connected to the secondary winding 1c.

The variable DC power supply 25 is constituted by, for example, the DC power supply 10 shown in FIG. It may also be configured by varying the potential applied.

Here, the inductances of the primary winding 21, secondary winding 22, and inductor 13 are respectively! 1°112, I13
Assuming that, the following equations (1) to (3) hold true.

When an AC voltage Vi is applied across the primary winding 21 and the inductor 13, voltages Vl and V2 that satisfy the following equation (1) are generated across the primary winding 21 and the inductor 13, respectively.

Furthermore, voltages Vl and V3 are generated in the secondary winding 22 that satisfy the following equation (2).

As shown in the figure, if the coil winding direction is such that voltage V3 and voltage V2 generate voltages in opposite directions, AC voltage (V3- V2) satisfies the following (3) from the above equations (1) and (2).

V 3 V 2 = (11,3/kI)
V I V 2= (Il, 3/i2) V3-
V2=((Il, 3/I12)-1)V2...
(3) Furthermore, the inductance I13 of the primary winding 21 and the inductance ℃2 of the inductor 13 have the same value (J13; ℃2
), the AC voltage (V3-V2) generated across the resistor 24 and the variable DC power supply 25 becomes "0". That is, the AC voltage Vi is canceled, no AC voltage is applied to the variable DC power supply 25, and the DC voltage E2 from the variable DC power supply 25 is applied to the secondary winding 22. Note that the ratio between inductance I13 and inductance A2 is 0.
．． By setting it to 7 to 1.3, the AC voltage (■3-V2
) can be suppressed to ±0.3·v2.

Then, when the DC voltage E2 from the variable DC power supply 25 is applied to the secondary winding 22, the DC current I flows through the resistor 24, the secondary winding 22. This DC current I flows through the inductor 13, and the DC current I is superimposed on the AC current flowing through the inductor 13, so that the inductance of the inductor 13 can be varied by 2, and when the capacity of the DC current ■ is increased, the inductor 13 is Magnetic saturation is caused and 2 can be further varied by inductance.

Note that by making the hysteresis curve and the magnetic saturation characteristics the same, a stable variable inductor can be constructed by keeping the ratio of the inductance I1.3 and the inductance 2 constant.

Next, the operation of the circuit shown in FIG. 1 will be explained.

When the oscillator 3 turns on and off the transistor 2, eight AC voltages are generated across the secondary windings 1b and 1c of the transformer 1, and a rectifier consisting of a diode 4 and a capacitor 5 is connected to the inductor (secondary winding) Ib side. The circuit generates a DC voltage. Note that this DC voltage may be used for the DC power supply 10.

In this state, when the switch SW is turned on and the transistor 9 is turned off, the inductance made up of the primary winding 21 and the inductor 13 becomes maximum, and the alternating current applied via the secondary winding 1C flows through the lamp 32. The current flows through one filament of the switch SW, the other filament of the lamp 32, and the variable DC power supply 25. However, as described above, the combined inductance of the primary winding 21 and the inductor 13 is too high, so the lamp 32 is turned off.

On the other hand, when the switch SW is turned on, the filament current flowing through the filament of the lamp 32 is detected by the alternating current detection means 6 via the resistor 7, and the drive means 8
turns on/off transistor 9, variable DC power supply 2
5, the DC current flowing from the DC power source 10 is controlled, and 1
Since the combined inductance of the secondary winding 21 and the inductor 13 decreases, an alternating current with a constant direct current superimposed flows through the filament of the lamp 32, and a constant current flows through the filament to preheat it.

Further, when the switch SW is turned off, the alternating current is cut off, and the alternating current voltage applied to both ends of the secondary winding 1C is applied between both filaments of the lamp 32. For this reason,
The lamp 32 receives a starting voltage and lights up, and a tube current flows through the lamp 32. This tube current is detected by the alternating current detection means 6 via the resistor 7, and the drive means 8 turns on/off the transistor 9, thereby making it possible to control the tube current to a constant value.

In this way, the inductor 13 is connected in series with the inductor of the transformer 1, and the lamp 32 is connected to the inductor variable section 12, which is composed of the primary winding 21 and the secondary winding 22, which have the same inductance as the inductor 13. connect,
By applying direct current from the direct current power supply 10 to the inductor 13 and the primary winding 21, the composite inductance connected to the lamp 32 can be varied.

In the above embodiment, the tube current of the lamp 32 is
Although the case has been described in which the tube current of the lamp 32 is controlled by detecting the voltage through the resistor 7 connected to the resistor 7, the tube current of the lamp 32 may also be controlled by detecting the voltage of the lamp 32 during preheating.

Further, in the above embodiment, a case has been described in which the inductor variable section 12 is constituted by the primary winding 21 of the transformer and one inductor 13, but it may be constituted by an inductor with a center tap instead of the transformer.

Further, in the above embodiment, the case where the alternating current is generated from the secondary winding 1c has been described, but a multi-output power supply may be used.

〔Effect of the invention〕

As explained above, the present invention connects an inductor and a transformer to the series through the primary winding of the transformer to the filament of the lamp, and provides a DC power source that variably superimposes a DC current on the AC current generated by the inductor. Since the part is arranged through the secondary winding of the transformer, which has the same inductance as the inductor and has the opposite polarity, the AC current component supplied from the transformer power supply can be adjusted without changing the AC voltage supplied from the transformer power supply. is canceled by the inductor and the secondary winding of the transformer connected to this inductor,
Preheating current can be supplied to the filament from a DC power source while varying the composite inductance connected to the lamp filament.

Therefore, by simply using a portion of the multi-output power supply that makes up the hardware power supply circuit, it is possible to variably control the AC power supply, and in particular, the drive circuit that drives the lamp can be greatly simplified, significantly reducing circuit costs. It has excellent effects such as being able to lower the

[Brief explanation of the drawing]

FIG. 1 is a power supply circuit diagram illustrating the configuration of a lamp drive power source showing an embodiment of the present invention, FIG. 2 is a circuit diagram illustrating the configuration of the inductor variable section shown in FIG. 1, and FIG. FIG. 2 is a circuit diagram illustrating an example of a conventional lamp drive power source. In the figure, 1 is a transformer, 2 and 9 are transistors, 3 is an oscillator, 6 is an alternating current detection means, 7 is a resistor, 8 is a drive means, and 1o is a direct current power supply.

Claims (1)

[Claims] In a lamp drive power supply that applies AC voltage output from a transformer power supply to the lamp to light the lamp,
An inductor and a transformer are connected to the series through the primary winding of the transformer to the filament of the lamp, and a DC power supply section that variably superimposes a DC current on the AC current generated in the inductor has the same inductance as the inductor. A lamp driving power source, characterized in that the lamp drive power source is arranged through the secondary winding of the transformer, which has opposite polarity.