JPH07183142A - Dimmer discharge lamp stabilizer - Google Patents

Abstract

PURPOSE:To provide a compact, light weighted and low cost dimmer discharge lamp stabilizer capable of stepwise dimming without disconnecting the feed current to the lamp. CONSTITUTION:The dimmer discharge lamp stabilizer is provided with an iron core structure 21, the primary winding 24 engaged with the central leg 22a of this iron core structure 21 and the first secondary winding 25a and the second secondary winding 25b positioned on both sides of this primary winding 24 to be engaged with the central leg 22a. The second secondary winding 25b is parallel-connected to the first secondary winding 25a through the intermediary of a switch 30. On the other hand, the first and second secondary windings 25a, 25b are series-connected at least to a part of the primary winding 24. Through these procedures, the composite impedance of both secondary windings 25a, 25b can be changed corresponding the the making and breaking of the switch 30 so that the feed current to the lamp may be controlled to make two step dimming feasible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimming discharge lamp ballast for adjusting the brightness of a discharge lamp in two steps.

[0002]

2. Description of the Related Art For example, in a streetlight fixture for lighting a road (road), the brightness is reduced by one level at midnight when the traffic volume is small as compared with the normal lighting. Such dimming is commonly called stepped dimming as opposed to continuous dimming.

In the case of stepwise dimming, the impedance of the discharge lamp ballast used in the lighting circuit may be changed,
Fig. 4 suitable for stepped dimming of fluorescent lamps
And a dimming discharge lamp ballast A shown in FIG. 5 and a dimming discharge lamp stabilizer shown in FIGS. 6 and 7 suitable for stepped dimming of so-called HID lamps such as mercury lamps, metal halide lamps, and high pressure sodium lamps. Vessel B is known.

The conventional dimming discharge lamp ballast A shown in FIGS. 4 and 5 has a core structure formed by combining a T-shaped core 1 and a pair of L-shaped cores 2 as shown in FIG. Primary winding 3
A leakage transformer formed by providing a secondary winding 4 and a pair of pass cores 5. The primary winding 3 and the secondary winding 4 are provided by being fitted to the central legs 1a of the T-shaped iron core 1, respectively, and the pair of pass cores 5 are located between the windings 1 and 2 and the central legs are provided. It is arranged so as to be sandwiched between 1a and the side leg 2a of the L-shaped iron core 2.

The primary winding 3 of the ballast A is connected to the power source 6 as shown in FIG.
One end of the secondary winding 4 is connected to the intermediate tap 3a. A first relay switch 7a is connected to the other end of the secondary winding 4, and an intermediate tap 4a of the secondary winding 4 is connected.
The second relay switch 7b is connected to. Both switches 7a and 7b are connected to a power source 6 via a fluorescent lamp 8, respectively. In FIG. 4, 9 is both switches 7
A relay coil for opening and closing a and 7b in conjunction with each other, 10 is a relay power source, and 11 is a capacitor.

In the dimming discharge lamp ballast A having such a configuration, when the first relay switch 7a is closed and the second relay switch 7b is opened, the fluorescent lamp 8 is passed through the entire secondary winding 4. The rated current is supplied and the lamp 8 is turned on. When the first relay switch 7a is open and the second relay switch 7b is closed, the impedance of the secondary winding 4 changes according to the winding amount determined by the position of the intermediate tap 4a. The current supplied to the fluorescent lamp 8 is reduced, and the dimming is performed.

Another conventional dimming discharge lamp ballast B shown in FIGS. 6 and 7 is constructed by adding a choke coil 13 to the leakage transformer shown in FIGS. 4 and 5. Since the configuration of the leakage transformer has already been described, the same components are designated by the same reference numerals and the description thereof will be omitted. The choke coil 13 added is shown in FIG.
As shown in FIG. 2, the E-shaped iron core 14 and the I-shaped iron core 15 are combined into an iron core structure, and the central leg 14 of the E-shaped iron core 14 is provided.
It is formed by providing a choke coil winding 16 fitted to a.

As shown in FIG. 6, one end of the secondary winding 4 is connected to the intermediate tap 3a of the primary winding 3 connected to the power source 6. To the other end of the secondary winding 4, a Chuuk coil winding 16 is connected and a relay switch 17 is connected. The choke coil winding 16 and the relay switch 17 are connected to the power supply 6 via the HID lamp 18, respectively. In addition, 19 in FIG. 6 is a relay coil for opening and closing both relay switches 17.

In the dimming discharge lamp ballast for HID lamps having such a structure, the relay coil 19 is opened / closed to change the combined impedance on the secondary side, and thus the leakage transformer, that is, When the choke coil winding 16 is added to the discharge lamp ballast A shown in FIGS. 4 and 5, the HID lamp 1
8 can be lit at the rated current, and when the choke coil winding 16 is disconnected, the current supplied to the HID lamp 18 can be reduced to perform step dimming.

[0010]

As in the dimming discharge lamp ballast A shown in FIGS. 4 and 5, an intermediate tap 4a is provided in the secondary winding 4 to perform step dimming by switching the taps. In the configuration, the relay coil 9 includes the first and second relay switches 7 and 7.
When switching between a and 7b, the fluorescent lamp 8
The current supplied to the lamp is cut off and the fluorescent lamp 8 goes out. Therefore, this ballast A is unsuitable for stepped dimming of HID lamps.

In other words, the HID lamp requires several minutes to re-light after being turned off due to its characteristics, and in addition, it takes several minutes until the predetermined brightness is reached after re-lighting. is necessary. Therefore, when the HID lamp used for road lighting or the like is stepwise dimmed by the dimming discharge lamp ballast A shown in FIGS. 4 and 5 at midnight or the like, the HID lamp is turned off with the stepwise dimming. However, there is a problem in that the discharge lamp ballast A for dimming shown in FIGS. 4 and 5 cannot be used for step dimming of the HID lamp.

Further, in the dimming discharge lamp ballast B shown in FIG. 6 and FIG. 7, the HID lamp 18 is not turned off because the supply current is not cut off even for a moment due to the step dimming. . However, since the choke coil 16 is added for that purpose, the amount of windings and iron core required for the ballast B is large, and therefore, there is a problem that the ballast is heavy and large, and the cost is high. There's a problem.

An object of the present invention is to obtain a discharge lamp ballast for dimming which is small in size, light in weight and inexpensive, as well as being capable of stepwise dimming without interruption of the current supplied to the lamp.

[0014]

In order to achieve the above object, a dimming discharge lamp ballast according to the present invention comprises an iron core structure and a primary winding provided by being fitted to a central leg of the iron core structure. A first secondary winding and a second secondary winding provided on both sides of the primary winding and fitted to the central leg, the first secondary winding and the second secondary winding being provided with respect to the first secondary winding. Two secondary windings are connected in parallel via a switch, and the first and second secondary windings are connected in series with at least a part of the primary winding.

[0015]

In the above structure, by opening and closing the switch, the second secondary winding of the secondary winding is added to or separated from the lamp, so that the first secondary winding and the second secondary winding. Can be varied to control the supply current to the lamp accordingly. That is, when the switch is closed, the rated current is supplied to the lamp through the first and second secondary windings, and when the switch is opened, the current supplied to the lamp is supplied to the first secondary winding. Only the current that has passed through the lamp is used, and the lamp is dimmed in two stages due to the impedance change associated with such switching.

Further, in this structure, the electricity is supplied to the lamp through the first secondary winding regardless of whether the switch is opened or closed. As a result, the lamp is not turned off with stepped dimming, which is suitable not only when using a fluorescent lamp as the stepped dimming lamp but also when using an HID lamp. Further, a choke coil is not added to perform the step dimming, and the secondary winding is
Since the size of the iron core structure can be increased slightly in accordance with the division into the second both secondary windings, compared with the conventional dimming discharge lamp ballast with a choke coil. It can be small and lightweight.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. FIG. 2 is a plan view showing the configuration of the dimming discharge lamp ballast C according to the first embodiment.
The core structure shown by 1 includes a T-shaped core 22 formed by stacking a large number of core plates punched into a T-shape, and a pair of L-shaped cores 23 formed by stacking a plurality of core plates punched in an L-shape. Are formed so that the central leg 22a of the T-shaped iron core 22 and the side leg 23a of the L-shaped iron core 23 are parallel to each other.

A primary winding 24 is fitted to the central leg 22a, and a first secondary winding 25a forming a secondary winding.
And the second secondary winding 25b are fitted into each other. The first and second secondary windings 25a and 25b are arranged on both sides of the primary winding 24, respectively. A pair of first pass cores 26 is provided between one end of the primary winding 24 and the first secondary winding 25a, and the other end of the primary winding 24 and the second secondary winding 2 are provided.
A pair of second pass cores 27 is also provided between the second pass cores 27 and 5b. Both the first and first pass cores 26, 27 are arranged so as to be sandwiched between the central leg 22a and the side leg 23a.

FIG. 2 is a diagram showing a circuit configuration of the dimming discharge lamp ballast C having the above-mentioned configuration. As shown in FIG. 2, both ends of the primary winding 24 are connected to a 200 V power source 28. At the same time, a capacitor 29 is connected in parallel to the winding 24. In contrast to the first secondary winding 25a arranged on one end side of the primary winding 24, the second secondary winding 25b arranged on the other end side of the primary winding 24 is connected in series with this winding 25b. They are connected in parallel via the connected switch 30.

The primary winding 24 has an intermediate tap 24a, to which the first secondary winding 25a and the second secondary winding 25b are connected. Therefore, the first secondary winding 25a and the second secondary winding 25b primary winding 2
4 are connected in series.

The switch 30 and the first secondary winding 25a are at H level.
It is connected to the power supply 28 via the ID lamp 31. H
The ID lamp 31 is, for example, for road lighting, and a mercury lamp, a metal halide lamp, a high pressure sodium lamp, or the like can be used for this. The switch 30 is opened and closed by a relay coil 33 controlled by a relay control power supply 32. The relay control power source 32 energizes the relay coil 33 when a predetermined time (midnight) by a repeat timer (not shown) or the like is reached, and opens the switch 30 to maintain the state for a predetermined time. Has become.

The dimming discharge lamp ballast C having the above structure is a step-down type leakage transformer that steps down the voltage of the power supply 28 applied across the primary winding 24 and discharges it to the secondary side. There is. In this ballast C, when the switch 30 is held in the closed state, the current passing through the first secondary winding 25a and the first current connected to the winding 25a in parallel via the switch 30 are connected. The electric currents passing through the secondary winding 25b and the switch 30 are supplied to the HID lamp 31, respectively, and the HID lamp 31 is lit with the brightness corresponding to the electric current value and is used for road lighting.

When the switch 30 is opened by the relay control power supply 32 via the operation of the relay coil 33, the second secondary winding 25b is separated from the HID lamp 31, so that the first Only the current passing through the secondary winding 25a is supplied to the HID lamp 31, and the HID lamp 31 is lit with the brightness according to the current value.

By opening and closing the switch 30 in this manner, both the first and second secondary windings 25 constituting the secondary winding are formed.
Of the a and 25b, the second secondary winding 25b can be added to or cut off from the first secondary winding 25a to change the combined impedance of the entire secondary winding, and the HID lamp 31 accordingly. It is possible to switch the brightness in two steps (step dimming) by controlling the current supplied to the bed.

According to this stepwise dimming, the current passing through the first secondary winding 25a can be always supplied to the HID lamp 31 regardless of whether the switch 30 is opened or closed after the HID lamp 31 is turned on. The current supplied to the power supply will not be interrupted and the light will not be turned off. Therefore, the safety of road (road) lighting can be secured.

In the dimming discharge lamp ballast C, as described above, the secondary winding in the leakage transformer is formed by the first and second secondary windings 25a and 25b, and one of them is formed. This is a configuration that realizes two-step dimming by adding or disconnecting the secondary winding of the other secondary winding to or from the other secondary winding. There is no need to add a choke coil.

The size of the iron core structure 21 is required to be slightly larger than that of a single secondary winding corresponding to the pair of divided secondary windings 25a and 25b. As described above, since the choke coil can be omitted, the winding amount and the amount of the iron cores 22 and 23 forming the iron core structure 21 can be smaller than those of the conventional dimming discharge lamp ballast to which the choke coil is added. Therefore, as compared with the conventional dimming discharge lamp ballast to which the choke coil is added, the discharge lamp ballast C can be made smaller and lighter, and the cost can be reduced accordingly.

FIG. 3 is a view showing an electric circuit of a dimming discharge lamp ballast D according to a second embodiment of the present invention, which is formed by a step-up type leakage transformer. Therefore, the power supply 28 is set to 100V, one end of the primary winding 24 on the side of the first secondary winding 25a and the intermediate tap 24a are connected to the power supply 28, and the power supply 28 is not a part of the primary winding 24. First secondary winding 25 for the whole
a and the second secondary winding 25b are connected in series. Since the configuration other than the points described above is the same as that of the first embodiment including the configuration not shown, the same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the second embodiment, the voltage applied to the primary winding 24 is applied to both the first and second secondary windings 25.
a, 25b, except that the pressure is released and the first
The same operation as that of the embodiment is obtained, whereby the initial object of the present invention can be achieved also in this second embodiment.

Although each of the above-mentioned embodiments is configured as described above, the present invention is not limited to these embodiments, and a light source whose lamp current is controlled by the discharge lamp ballast of the present invention is , HID lamps as well as fluorescent lamps may be used.

[0031]

As described above in detail, according to the dimming discharge lamp ballast of the present invention, the switch for changing the combined impedance of the first and second secondary windings to perform the step dimming. Regardless of whether the lamp is opened or closed, it is possible to guarantee the energization of the lamp through the first secondary winding and prevent the lamp from being extinguished. Therefore, it can be used as a ballast for a fluorescent lamp in a step-dimmed lamp. That is, it can be used as a ballast for HID lamps. Furthermore, because a choke coil is not added to perform stepped dimming, both windings and iron cores are smaller and smaller than conventional dimming discharge ballasts that add choke coils. The weight can be reduced and the cost can be reduced accordingly.

[Brief description of drawings]

FIG. 1 is a diagram showing a circuit configuration of a dimming discharge lamp ballast according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the configuration of a dimming discharge lamp ballast according to the first embodiment.

FIG. 3 is a diagram showing a circuit configuration of a dimming discharge lamp ballast according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a circuit configuration of a dimming discharge lamp ballast according to a first conventional example.

FIG. 5 is a plan view showing the configuration of a discharge lamp stabilizer for light control according to the first conventional example.

FIG. 6 is a diagram showing a circuit configuration of a dimming discharge lamp ballast according to a second conventional example.

FIG. 7 is a plan view showing a configuration of a dimming discharge lamp ballast according to the second conventional example.

[Explanation of symbols]

21 ... iron core structure, 22a ... central leg, 2
4 ... Primary winding, 25a ... 1st secondary winding, 25b ... 2nd secondary winding, 31 ... Switch, 31 ... HID lamp (lamp).

Claims (1)

[Claims] Claim: What is claimed is: 1. An iron core structure, a primary winding fitted to a central leg of the iron core structure, and first and second windings located on both sides of the primary winding and fitted to the central leg. A secondary winding and a second secondary winding, wherein the second secondary winding is connected in parallel to the first secondary winding via a switch, and the first and second secondary windings are connected. A ballast for a discharge lamp, wherein a winding is connected in series with at least a part of the primary winding.