JPS6055972B2 - Leading phase leakage transformer type discharge lamp ballast - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a phase advance leakage transformer type discharge lamp ballast, and more particularly to an arrangement of windings constituting a magnetic circuit.

In general, the current-limiting impedance required to keep a discharge lamp lit is usually controlled by a magnetic leakage transformer in the case of a lagging phase, and the magnetic coupling between the primary winding on the power supply side and the secondary winding on the load side. It is obtained by the inductance generated by In the case of phase advance, it is obtained as the total impedance of this inductance and the capacitance of the capacitor inserted on the load side. In the case of phase advance, the magnetic circuit is magnetically saturated due to the excitation magnetic flux on the primary winding side and the direction of the load magnet being polarized, so this magnetic saturation is suppressed, and the lamp current close to the rectangular wave characteristic of phase advance is suppressed. To obtain the waveform, the third
As shown in the figure, a primary winding P and a secondary winding S are wound around an iron core 1 through a magnetic shunt 2, and a slit 4 is formed in the secondary magnetic path of the iron core 1, leaving a bridge 3. The magnetic path between the primary winding P and the secondary winding s is partially separated. In addition, looking at the waveforms of the phase-advanced lamp current il, the wrap voltage ■, and the no-load secondary voltage V2O, as shown in Figure 1, the no-load secondary voltage waveform is near the top of the sine wave (period ■)
and a base part (period I) in which the sine wave is constricted, and period I is a period in which the bridge 3 of the remaining bonded part that formed the slit 4 is saturated, and the period (■) is a period in which the bridge 3 is not yet present. This is a period of saturation.

Looking at the energy transfer process, during period ■, the energy of the power supply passes through bridge 3 as magnetic flux, and current flows through the series circuit of the wrap load and the impedance of the sum of the inductance of the secondary winding S and the capacitance of the capacitor. . At this time, the capacitor is charged with electric charge. Therefore, the larger the bridge 3 of the secondary winding S and the larger the number of turns of the secondary winding S, the more the inductance increases, the composite impedance of the sum with the capacitance decreases, and the leading phase lamp current i in the period
The top of the l waveform becomes higher. In addition, in the next period I, the bridge 3 is saturated, the inflow of magnetic flux energy from the power supply is cut off, and the charge charged in the capacitor in the previous period ■ is discharged, and at this time, the direction of the phase-advanced lamp current il waveform is is reversed with respect to the previous period ■. At this time, the excitation magnetic flux and the load magnetic flux are in the same direction, but since the excitation magnetic flux is blocked from entering, magnetic saturation of the secondary magnetic path is suppressed, and a decrease in magnetic permeability and an increase in iron loss are suppressed. . The lamp current il waveform obtained in this way approximates a rectangular wave, and the lamp voltage V1 waveform is a rectangular wave unique to discharge lamps, so the lamp power during the time period between the lamp current il waveform and the lamp voltage ■ is the lamp current 11 waveform. A large value can be obtained compared to the effective value of . Therefore, in order to obtain the lamp current 11 waveform, the shape of the slit 4 forming the bridge 3 and the number of turns of the secondary winding S are important factors.

The peak of the lamp current 11 during the period ■ can be increased by increasing the ampere turns of the secondary winding S, but if it becomes too high, the peak of the lamp current 11 during the period ■ will be too high. On the contrary, the lamp power efficiency decreases and the power capacity of the leaky transformer increases, which is uneconomical. Therefore, the circuit configuration of the normal phase advance leakage transformer type discharge lamp ballast shown in FIG. 3 is as shown in FIGS. 2A and 2B.
That is, the configuration shown in FIG. 2a has a primary winding P connected to the power source 5.
A secondary winding S is connected in series to the secondary winding S, and a discharge lamp 7 is connected via a capacitor 6 to both ends of the primary winding P and the secondary winding S in series.
This configuration is used when the lamp voltage V1 is relatively high with respect to the power supply voltage Vs (for example, when the fluorescent lamp 1
10W 2 pieces, power supply voltage 200V 1 lamp voltage 160■2
(in the case of a total of 320 V), the configuration shown in Figure 2b is that the primary winding P
The secondary winding S1 capacitor 6 and the discharge lamp 7 are connected in series to the middle tap 8 of This is the case when increasing the secondary ampere-turns (for example, one 100W fluorescent lamp, 100V power supply voltage).
1 lamp voltage 160cm (in the case of 1 lamp). However, Figure 2a
In the configuration shown in , if the number of turns of the secondary winding S and the volume of the secondary winding S are too large, for example, there may be a case where there are two fluorescent lamps of 110 W, power supply voltage of 100 V, lamp voltage of 2, and a total of 320 cm. In this case, if the configuration shown in Figure 2a is applied as is, the secondary ampere turns will be too large, resulting in excessive power capacity, resulting in increased power consumption and a larger ballast, which will be uneconomical. Since the secondary winding S is large, both outer ends of the primary winding P and the secondary winding S. A considerably large distance occurs, and the coupling ratio between the primary winding P and the secondary winding S decreases, making it difficult to start the discharge lamp 7 and causing flickering when the lamp is turned on. It has the disadvantage that it tends to flow inside, increasing iron loss. Therefore, it may be possible to completely combine part of the secondary winding with the primary winding in the circuit configuration shown in Figure 2 A and b to prevent the secondary ampere turns and the secondary winding from becoming large. .

As shown in FIGS. 4 and 5, this configuration includes a primary winding P1 connected to a power source 5 to which a power supply voltage is applied, and a secondary winding S formed by a portion S and a remaining portion P2. '', and the ends of the other portion P2 of the secondary winding S'', which is magnetically coupled to the primary winding P1 and considered to be a part of the primary winding, are connected in series. and the primary winding P1 and this primary winding P1
A magnetic shunt 2 is formed between the primary winding P'' and a portion S of the secondary winding S'' formed by the other portion P2 of the secondary winding S'' magnetically coupled to the iron core. 1, a magnetic flux control slit 4 is formed corresponding to a portion S of the secondary winding S''. A structure is adopted in which the primary winding P1 and the other part P2 magnetically coupled to the primary winding P1 are wound around the same spool with one of them being wound on the inside and the other on the outside.
In this configuration, the volume of the primary winding P'' formed by the sum of the primary winding P1 and a portion P2 of the secondary winding S'' magnetically coupled to the primary winding P1 becomes large, and the volume of the primary winding P'' becomes large. The distance between the ends of the wire P1 and the portion S of the secondary winding S'' becomes considerably large, and the coupling ratio between the primary winding P1 and the portion S of the secondary winding S'' is reduced. As a result, it becomes difficult to start the discharge lamp 7, causing flickering during lighting of the discharge lamp 7, and high frequency magnetic flux tends to flow into the iron core 1, increasing iron loss. The present invention has been made in view of the above drawbacks.
The primary winding and a portion of the secondary winding are magnetically coupled via a magnetic shunt, with the remaining portion of the secondary winding being opposite the portion of the secondary winding with respect to the primary winding. If the lamp voltage is relatively high compared to the power supply voltage, the power capacity will be small.
Moreover, the present invention provides a ballast for a discharge lamp of the phase lead/leakage transformer type, which consumes less power, can be made small and lightweight, is economical, and has good lighting characteristics.

Next, the configuration of an embodiment of the present invention will be explained with reference to FIGS. 4 and 6.

The iron core 1 is wound with a primary winding P1 to which a power supply voltage is applied, and parts S and P2 obtained by dividing the secondary winding and winding each separately.

A magnetic shunt 2 is disposed between the primary winding P1 and a portion S of the secondary winding, and a slit for magnetic flux control is provided in the iron core 1 in a portion that becomes the magnetic path of the portion S of the secondary winding. form 4.

Further, the remaining part P2 of the secondary winding is arranged on the opposite side of the part S of the secondary winding via the primary winding P1. In other words, the order of the coils wound around the iron core 1 is a part S of the secondary winding,
This constitutes the primary winding P1 and the remaining other portion P2 of the secondary winding. In this configuration, there is no magnetic shunt between the primary winding P1 and the remaining part P2 of the secondary winding, and a slit for magnetic flux control is also formed. There is almost no magnetic action between the primary winding P1 and the remaining part P2 of the secondary winding, resulting in perfect magnetic coupling. This results in an ideal voltage transformation effect. Then, set the voltage of each coil as follows. The primary winding P1 is set to the power supply voltage or a value close to it, and the sum of the voltages of the primary winding P1 and the secondary winding S+P2 is set to the minimum value of the lighting sustaining voltage.

This configuration results in a ballast with the lowest secondary voltage for starting and maintaining the discharge lamp and the lowest impedance for limiting the lamp current.

Furthermore, by placing the primary winding P1, which is a coil to which a power supply voltage is applied, adjacent to a part S and the remaining part P2 of the secondary winding, the primary winding P1 and the remaining part P2 of the secondary winding are arranged adjacent to each other. The primary winding P1 and the part S of the secondary winding are almost completely coupled together, and the decrease in coupling rate due to the minimum magnetic shunt 2 and magnetic flux control slit 4 can be suppressed. Therefore, a secondary voltage with a good coupling ratio with respect to the power supply voltage and a small voltage drop is obtained, and the lamp starts discharging and transitions to a stable sustained discharge, resulting in good starting of the lamp.

Further, as shown in FIG. 1, the lamp current 11 is almost the third
It is clear that it is sufficient to consider up to the 5th harmonic, which is approximated to harmonics, and these harmonics are caused by the magnetic saturation of the bridge 3 adjacent to the magnetic flux control slit 4 and the magnetic imbalance, as described above. Obtained by saturation.

And since there are almost no harmonics higher than this in the lamp current, there are almost no harmonics corresponding to this frequency in the lamp current, so high-frequency magnetic flux corresponding to this frequency is generated in the ballast. However, it does not contribute as impedance for lamp current control, but is consumed as iron loss in the ballast. For example, using a long secondary winding,
If the distance between the primary winding and the secondary winding is increased, the magnetic distribution will be unevenly distributed, high frequency leakage magnetic flux will occur, the coupling ratio between the saw primary winding and the secondary winding will decrease, and the inductance will decrease. This results in poor lamp starting, reduced lamp power efficiency, and increased ballast losses. Therefore, it is effective to place the single thorn winding P, and a portion S of the secondary winding, which is the minimum required for limiting the lamp current, adjacent to each other. A ballast for a discharge lamp using a phase-advancing leakage transformer that is practical and has good lighting characteristics can be obtained.

Next, we set two fluorescent lamps of 110 W, power supply voltage of 100 V, lamp voltage of 160 V x 2 = 320, the power of each lamp was adjusted by a capacitor so that they were the same, and we changed the arrangement of the primary and secondary windings for comparison. Then, the result will be as shown in the table below. Examples 1 and 2 are part of the secondary winding of the present invention S1 primary winding P
Example 3 is a case in which the remaining parts P2 of the secondary winding 1 are arranged in the order of the remaining parts P2 of the secondary winding S.
This is a case where the primary windings P1 are arranged in the order, and a magnetic shunt 2 is provided between the primary winding P1 and a portion S of the secondary winding.
A slit 4 is formed in the magnetic path of a portion S of the secondary winding.

As is clear from the table above, Examples 1 and 3 are cases where the number of turns of the primary winding and secondary winding are the same, and the no-load secondary voltage is higher in Example 1 than in Example 3. It can be seen that the case of Example 1 has a good binding rate.

In example 2, the number of turns of the remaining part P2 of the secondary winding is adjusted so that the no-load secondary voltage is the same as in example 3. It can be seen that the starting voltage is low despite the low voltage, and the starting is good. In addition, the lamp voltage is almost the same in Examples 1, 2, and 3, but the lamp current is lower in Examples 1 and 2 than in Example 3, which indicates that Examples 1 and 2 have higher lamp power efficiency. .

Since the secondary short circuit current is smaller in A and B than in Example 3, it can be seen that Examples 1 and 2 have higher power efficiency.

Furthermore, since the secondary short circuit current is smaller in Examples 1 and 2 than in Example 3, it is possible that the permeability in Examples 1 and 2 decreases due to pole saturation due to generation of high-frequency magnetic flux due to uneven distribution of magnetic flux in the magnetic path. It turns out that there are few. In addition, since the secondary short circuit current is less in Examples 1 and 2 than in Example 3, in Examples 1 and 2 the magnetic permeability decreases due to pole saturation due to generation of high frequency magnetic flux due to uneven distribution of magnetic flux in the magnetic path. You can see that there are few things happening. Furthermore, since power loss is smaller in Examples 1 and 2 than in Example 3, Examples 1 and 2 have less power capacity and less power consumption, and therefore can be made smaller and more economical.

Next, the structure of another implementation will be described with reference to FIG.

In the above embodiment, a configuration in which a magnetic shunt is not interposed between the primary winding P1 and the other part P2 of the secondary winding has been described, but in this configuration, the primary winding P1 and the other part P2 of the secondary winding
A magnetic shunt 8 is interposed between the two, and the other configuration is the same as that shown in FIG.

In this configuration, since there is no magnetic flux control slit in the magnetic path of the other part P2 of the secondary winding, the primary winding P1 is
By adjusting the degree of coupling using the magnetic shunt 8, it is possible to limit mainly the fundamental wave component of the lamp current.

According to the present invention, a portion of the primary winding and the secondary winding are magnetically coupled via a magnetic shunt, a magnetic flux control slit is formed in the magnetic path of the portion of the secondary winding, and a slit for controlling the magnetic flux is formed in the magnetic path of the portion of the secondary winding. Because the other parts of the secondary winding are placed on the magnetic path on the opposite side of the primary winding from the secondary winding, the action of the phase advancing magnetic leakage transformer is The magnetic action between the primary winding and the other parts of the secondary winding is almost completely magnetically coupled, resulting in an ideal transformation action. In other words, a part of the secondary winding and the other part of the secondary winding can be placed adjacent to the primary winding that serves as the power supply voltage applying coil, and the primary winding and the other part of the secondary winding are almost completely coupled. In addition, a portion of the primary winding and the secondary winding can suppress a reduction in the coupling ratio due to the minimum magnetic shunt and control slit. Furthermore, the magnetic saturation and magnetic unsaturation of the bridge adjacent to the slit formed in the magnetic path of a portion of the secondary winding contributes to impedance for limiting the lamp current, and an optimum lamp current can be obtained. Furthermore, since the primary winding and the minimum secondary winding necessary for limiting lamp current can be placed adjacent to each other, the starting voltage is low and starting is performed well, the lamp power efficiency is high, the power capacity is low, and the power consumption is low. Accordingly, a ballast for a discharge lamp of the type leakage transformer, which is small and lightweight, economical, and has good lighting characteristics, can be obtained. In addition, a magnetic shunt is interposed between the primary winding and other parts of the secondary winding, and since there is no control slit in the magnetic path of the other part of the secondary winding, the primary winding is The degree of coupling between the primary winding and other parts of the secondary winding can be adjusted using a magnetic shunt, and the fundamental wave component of the lamp current can be limited, so the primary winding and the secondary winding can be Coupled with flux control between sections of wire, an efficient ballast is obtained.

[Brief explanation of drawings]

Figure 1 is a waveform diagram, Figures 2A and b are circuit diagrams of a conventional discharge lamp ballast, Figure 3 is a cross-sectional plan view of the same ballast, and Figure 4 is a diagram of the discharge lamp ballast of the present invention. 5 is a cross-sectional plan view of a discharge lamp ballast which is a premise of the present invention, FIG. 6 is a cross-sectional plan view of a discharge lamp ballast showing an embodiment of the present invention, and FIG. 7 is a cross-sectional plan view of a discharge lamp ballast that is a premise of the present invention. FIG. 7 is a cross-sectional plan view of a ballast for a discharge lamp showing another embodiment of the invention. P1...Primary winding, S...Part of the secondary winding, P2...Other part of the secondary winding, 2,8.
...Magnetic shunt, 4...Slit for magnetic flux control.

Claims (1)

[Claims] 1. A part of the primary winding and the secondary winding are magnetically coupled via a magnetic shunt, and a slit for magnetic flux control is formed in the magnetic path of the part of the secondary winding. and the remaining part of the secondary winding is arranged on a magnetic path opposite to the part of the secondary winding with respect to the primary winding. stabilizer. 2. The phase lead leakage according to claim 1, characterized in that a magnetic shunt is formed between the primary winding and the remaining part of the secondary winding that is magnetically coupled with the primary winding. Ballast for transformer type discharge lamps.