JPH046158Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a dimming discharge lamp lighting device.

The basic circuit of a dimming discharge lamp lighting device is shown in FIG. In the figure, E is an AC power supply, S is a flashing switch, T is a dimming phase control thyristor (triack), B is a dimming ballast, B1 is its auto-leakage transformer, and Tf is a built-in ballast B. There is a filament preheating transformer, and L is a fluorescent lamp.
That is, this device blinks the lamp L by turning on and off the blinking switch S, and when it is turned on, current is supplied to the filament preheating transformer Tf and the transformer B1 whose phase is controlled by the thyristor T to dim the lamp L. be.

However, since the filament preheating transformer Tf is built into the ballast B, there is a drawback that the ballast B is large and expensive.

For this reason, the filament preheating winding is wound directly around the shunt winding of the auto-leakage transformer built into the ballast.
In addition, it has been considered that the secondary side of the ballast is a phase advance type discharge circuit (for example, Japanese Patent Application Laid-Open No. 52-118977
issue). However, this dimming discharge lamp lighting device is provided with a delay circuit so that the dimming thyristor is fully conductive at the time of startup, and has the disadvantage of complicating the circuit.

Therefore, an object of this invention is to provide a dimming discharge lamp lighting device that has a simple circuit configuration and can be easily dimmed.

A first embodiment of this invention is shown in FIG. That is, in this dimming discharge lamp lighting device, a phase advancing capacitor C is inserted into the main discharge circuit of the lamp L to form a phase advancing discharge circuit, and a full lighting dimmer switch SW is connected in parallel to the dimming thyristor T. are connected in parallel, and the control of thyristor T is controlled by the dimming thyristor T.
The phase control angle is within the range of 0 to approximately π/2, that is, the dimming ratio is within the range of 100 to approximately 50%.

The operation of this dimming discharge lamp lighting device is as follows:
%, it can be used in the same way as a general fluorescent light by turning on the dimmer switch SW and simply turning on and off the flashing switch S. In addition, when using dimming, please use the dimmer switch.
Turn off SW and control on/off with blinking switch S. If you install a switch SW like this,
In addition to switching between dimming and non-dimming, there is the convenience of being able to turn on the light directly in the event of a failure in the thyristor T.

On the other hand, when using dimming, the voltage V and current Io at the time of starting are approximately
Therefore, if the thyristor T is turned on within a time T1 close to 90 degrees, the lamp L wound around the shunt winding P of the auto-leakage transformer B A predetermined voltage can be obtained in the filament preheating winding and the excitation current is 100
% conduction, the filament can be sufficiently preheated, the secondary voltage of the autotransformer is inevitably induced to a predetermined value, and the lamp L is in a state sufficient to start.

Further, in the lighting state, due to the influence of the phase advance capacitor C, the phase-lag excitation current and the phase-lead lamp current are combined, and the current changes to a slightly phase-lag current as shown in FIG. 3B. As a result, the circuit of this embodiment is capable of dimming while the lamp filament is sufficiently preheated when the phase control angle is between 0 and approximately π/2. For example, in the thyristor T that is set to turn on at time T1, current does not flow in the portion indicated by the broken line in the figure, and this time corresponds to the portion where the light is dimmed. Therefore, the conventional delay circuit is not required and the circuit configuration is simplified. In addition, as a dimming mode, the light output from the lamp L can be continuously changed from 100% to approximately 50%, and when it is fixed at a certain phase of 0 to π/2 (for example, 70%). By turning the dimmer switch on and off, you can obtain two levels of light output: 100% and 70%.

A second embodiment of this invention is shown in FIG. That is, in this dimming discharge lamp lighting device, the thyristor T is inserted into the shunt winding P of the auto-leakage transformer ballast B1 in the first embodiment. In this case as well, during starting (preheating), an excitation current with a phase delay of approximately π/2 flows, generating sufficient preheating voltage and secondary voltage for starting the lamp, and after lighting the lamp, the series phase-advanced discharge circuit is activated. Once formed, the thyristor current advances to approximately the same level as the power supply voltage phase, and is dimmed until it is turned on at time T1. However, in the case of this embodiment, since the insertion position of the thyristor T is connected in series with the shunt winding P, the thyristor current is only the current flowing through the shunt winding P, and its withstand voltage is also The capacitance of the thyristor only needs to be small. Furthermore, even in the section where the thyristor T is off, a closed circuit is formed through the series winding U of the ballast B1, so that the lamp current has no rest section and stable discharge continues.

As described above, the dimming discharge lamp lighting device of this invention has a thyristor on the primary side of a ballast with a filament preheating winding having a phase-advanced discharge circuit.
There is no need for a filament preheating transformer, making it compact and inexpensive, and since the phase control element is controlled within a phase control angle range of 0 to approximately π/2, it can be started reliably without the need for a conventional timer circuit, and the circuit configuration This has the effect of making it possible to provide a simple and inexpensive lighting device.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a conventional dimming discharge lamp lighting device, Fig. 2 is a circuit diagram of a dimming discharge lamp lighting device according to the first embodiment of this invention, and Fig. 3 is a voltage-current phase explanatory diagram. Figure 4 shows the circuit diagram of the dimming discharge lamp lighting device in the second embodiment. E...power supply, T...triax (thyristor), C...phase advancing capacitor, L...lamp, B,
B1... Ballast, P... Shunt winding, U... Series winding.

Claims (1)

[Claims for Utility Model Registration] (1) A ballast with a preheating filament winding, a phase advance discharge circuit formed on the secondary side of this ballast, and a phase advance discharge circuit formed on the A dimming discharge lamp lighting device comprising a dimming thyristor whose control angle is controlled within a range of 0 to approximately π/2. (2) The dimming system according to claim 1, wherein the ballast is an auto-leakage transformer, and the dimming thyristor is inserted into a shunt winding of the transformer. Discharge lamp lighting device. (3) The dimming discharge lamp lighting device according to claim 1 or 2, wherein a full lighting switch is connected in parallel to the dimming thyristor.