JPH0211997B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a discharge lamp device such as a fluorescent lamp, a mercury discharge lamp or a sodium discharge lamp.

As conventional discharge lamp devices, gross starter type and rapid starter type ones have been widely used. However, the glow starter method takes a long time to turn on the discharge lamp, making it unsuitable for applications where you want to turn on the lamp quickly.Since the glow starter is a contact point, it must be replaced if it fails, and the discharge lamp deteriorates. There are disadvantages such as the fact that it is easy to invite On the other hand, the rapid starter type has a relatively short startup time, but requires a dedicated large ballast and a dedicated lamp, which has the disadvantage of increasing the size and cost of the device.

In order to eliminate these drawbacks of conventional discharge lamp devices, a discharge lamp device (Japanese Patent Publication No. 48-28726) has been proposed in which a nonlinear capacitor is used as a starting element. This discharge lamp device, as shown in Fig. 1,
The circuit has a circuit configuration in which a nonlinear capacitor 3 is connected in parallel to the discharge lamp 1 and in series to the ballast 2. Reference numeral 4 denotes a switching circuit that supplies a preheating current to the filaments 1a and 1b of the discharge lamp 1 at startup, and is configured as various semiconductor non-contact switches.

The nonlinear capacitor 3 is made of barium titanate-based ferroelectric ceramic, and the relationship between the applied voltage V and the accumulated charge Q exhibits a square characteristic as shown in FIG.

Now, in FIG. 1, when an alternating current voltage e is applied between the power supply terminals U and V, the filaments 1a and 1b are preheated by the current accompanying the switching operation of the switching circuit 4 every half cycle. , the nonlinear capacitor 3 is charged. Since the nonlinear capacitor 3 exhibits saturation characteristics as shown in Figure 2, as its charging operation enters the saturation region, the current _I2 flowing to the ballast 2 decreases rapidly, causing the ballast 2 to have a high wave peak value. A back electromotive force is generated. As a result, if the filaments 1a and 1b are sufficiently preheated, the discharge lamp 1 is triggered by the counter electromotive force and lights up.

In this way, according to the discharge lamp device shown in FIG. 1, the characteristics of the nonlinear capacitor are skillfully utilized.
It is possible to realize a discharge lamp device that can light a discharge lamp using a non-contact method, has high reliability, and has a short startup time.

However, this discharge lamp device has a configuration in which the nonlinear capacitor 3 operates as a starting element together with the switching circuit 4, and this increases the size of the discharge lamp device.
The ballast 2, which is the main cause of weight increase and cost increase, is indispensable. For this reason, there has been a limit to the ability to reduce the size, weight, and cost of the device.

Another discharge lamp device using a nonlinear capacitor is disclosed in Japanese Patent Application Laid-open No. 35574/1983. However, the device disclosed in JP-A-51-35574 merely uses a non-linear capacitor instead of a normal type capacitor as the phase advancing capacitor of the ballast, as shown in FIG. It had the same drawbacks as the previous one.

It is an object of the present invention to eliminate these drawbacks and provide a discharge lamp device that is small, lightweight, inexpensive, has a long life, is highly reliable, and has a very short start-up time and excellent quick response. .

In order to achieve this object, a discharge lamp device according to the present invention includes a discharge lamp having a filament that also serves as a discharge electrode, a nonlinear capacitor connected in series to the filament of the discharge lamp, and a nonlinear capacitor connected in series to the filament of the discharge lamp, and a and an inductor connected to the inductor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The content of the present invention will be specifically described below with reference to the accompanying drawings, which are examples. FIG. 3 is a basic circuit diagram of a discharge lamp device according to the present invention, in which a nonlinear capacitor 5 is connected in series to the filament 1a or 1b of the discharge tube 1, which has filaments 1a and 1b that also serve as discharge electrodes. At the same time, the circuit configuration is such that an inductor 6 is connected in parallel between the filaments 1a and 1b.

The operation of the above basic circuit will be explained with reference to the waveform diagram of FIG. 4a. When AC voltage e is applied between terminals U and V, filament 1a → inductor 6 → filament 1
Charging current i flows in loop b, and filament 1
a and 1b are preheated. Filament 1a, 1b
When the electrodes 1a and 1b are sufficiently preheated, thermionic emission and local discharge of mercury occur in each of the filaments 1a and 1b, which are discharge electrodes, and a discharge between the electrodes 1a and 1b is easily induced.

On the other hand, when the charging operation of the nonlinear capacitor 5 progresses and the accumulated charge saturates according to the square characteristic shown in FIG. The impulse-like back electromotive force V _p =
-Ldi/dt occurs. Therefore, if the filaments 1a and 1b are sufficiently preheated, the discharge lamp 1 will be triggered by the counter electromotive force _Vp , and a discharge will occur between the filaments 1a and 1b, which are discharge electrodes.
Discharge lamp 1 lights up.

As described above, in the present invention, since the nonlinear capacitor 5 is configured to operate as a ballast, unlike a ballast using a conventional chiyoke coil, parts such as iron or copper that cause an increase in weight and size are required. Therefore, it is possible to achieve a reduction in size, weight, and cost. In particular, since the nonlinear capacitor 5 serving as a ballast can be constructed of a nonlinear capacitor made of barium titanate-based ferroelectric ceramic, the nonlinear capacitor 5 can be significantly smaller, thinner, lighter, and cheaper than conventional ones.

Further, since the inductor 6 is configured to operate as a starting element, a discharge lamp device that requires no maintenance and has a long life can be realized.

FIG. 5 shows another embodiment in which the basic form of FIG. 3 is further improved. In the basic form shown in Fig. 3, when the impedance of the inductor 6 is low, a discharge occurs between the filaments 1a and 1b, and when the discharge lamp 1 is lit, a discharge current i _L also flows through the inductor 6 (Fig. 4b). , efficiency becomes worse. Therefore, in the embodiment shown in FIG. 5, a switch 7 consisting of a bidirectional breakover semiconductor switch such as a diak is connected in series with the inductor 6, and when the tube voltage V _T falls below a certain level, the switch 7 is connected in series with the inductor 6. By automatically turning off inductor 7, the apparent impedance of the circuit including inductor 7 is increased, and the current i _L flowing through inductor 6 is limited or blocked as shown in FIG. Said switch 7
can also be constructed by connecting Shockley diodes D ₁ and D ₂ in parallel in opposite directions, as shown in FIG. Note that D ₃ and D ₄ in FIG. 6 are diodes that protect the Schockley diodes D ₁ and D ₂ .

Further, as illustrated in FIGS. 5 and 6, when the switch 7 of the starting device is configured with a semiconductor switch, it becomes a non-contact switch, which can contribute to reducing failures and preventing deterioration of the discharge lamp 1. .

As described above, the discharge lamp device according to the present invention includes a discharge lamp having a filament that also serves as a discharge electrode, a nonlinear capacitor connected in series to the filament of the discharge lamp, and a nonlinear capacitor connected in parallel to the discharge lamp. To provide a discharge lamp device which is small, lightweight and inexpensive because it is equipped with an inductor to be connected, has a long life, is highly reliable, and has excellent quick response with a very short start-up time. Can be done.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a conventional discharge lamp device using a nonlinear capacitor as a starting element, Fig. 2 is a square characteristic diagram of a nonlinear capacitor, and Fig. 3 is a basic form of a discharge lamp device according to the present invention. The circuit diagram, FIG. 4a is a waveform diagram explaining its operation, FIG. 4b is a waveform diagram of the tube voltage and inductor current after lighting the discharge lamp, and FIGS. 5 and 6 are waveform diagrams for explaining the operation of the discharge lamp. Each of the circuit diagrams and FIG. 7 for the different embodiments of the electric lamp device similarly shows waveform diagrams of the tube voltage and current after the discharge lamp is turned on. 1...discharge lamp, 1a, 1b...filament,
5...Nonlinear capacitor, 6...Inductor,
7...Switch.

Claims (1)

[Scope of Claims] 1. A discharge lamp having a filament that also serves as a discharge electrode, a nonlinear capacitor connected in series to the filament of this discharge lamp, and an inductor connected in parallel to the discharge lamp. A discharge lamp device characterized by: 2. The discharge lamp device according to claim 1, wherein a semiconductor switch is connected in series with the inductor in a connection circuit of the inductor to the filament.