JPS61277197A - Discharge lamp apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a discharge lamp device for lighting a fluorescent lamp or a similar discharge lamp, using the resonance characteristics of an electrostrictive vibrator.
Feedback is applied to the three-terminal switching element to keep it on and off, and the three-terminal switching element turns on and off the current flowing to the inductive ballast to generate a high-voltage pulse, thereby lighting the discharge lamp. The lighting is maintained.

BACKGROUND OF THE INVENTION The best known conventional discharge lamp devices are those that utilize a glow tube and an inductive ballast.

In this case, since the commercial AC power source was used as is, the inductive ballast used a magnetic core made of silicon steel plate, which has good characteristics in the low frequency range, and was designed to obtain a large inductance value of about 300 mH.

Problems to be Solved by the Invention As mentioned above, conventional discharge lamp devices use commercial AC power as is, which necessitates the use of heavy and large inductive ballasts. This has been a major obstacle in efforts to reduce size, weight, and cost.

Various circuit systems have been proposed to make inductive ballasts smaller, lighter, and cheaper, but most of them are combination circuits of LC components and require large capacitors and numerous electronic components. Ta.

Means for Solving the Problems In order to solve the above-mentioned conventional problems, the present invention provides a discharge lamp, an inductive ballast that generates a high-voltage pulse to drive the discharge lamp, and a high-voltage pulse that flows through the inductive ballast. a three-terminal switching element that turns on and off a current; an electrostrictive vibrator connected in parallel to the discharge lamp and in series to the inductive ballast; The present invention is characterized in that it includes a feedback circuit that feeds back a vibration signal generated due to the electrostrictive phenomenon to the control electrode of the three-terminal switching element.

Operation The discharge lamp device according to the present invention drives an electrostrictive oscillator through an inductive ballast, and utilizes its resonance characteristics to provide feedback from the electrostrictive oscillator to the control electrode of a three-terminal switching element. The on/off operation is continued, and the current flowing through the inductive ballast is turned on/off by the on/off operation of the three-terminal switching element. This generates a high-voltage pulse in the inductive ballast that depends on the self-inductance and the rate of change in current over time associated with the on/off operation of the three-terminal switching element. This high-voltage pulse is then applied to the discharge lamp to turn it on.

The self-inductance value of the inductive ballast and the value of the capacitance between the drive electrodes of the electrostrictive vibrator are made to approximately match the natural resonance frequency of the electrostrictive vibrator, and a feedback signal corresponding to the natural resonance frequency of the electrostrictive vibrator is generated. to occur. Then, the signal of this natural resonance frequency is applied to the control electrode of the three-terminal switching element, and the three-terminal switching element is turned on and off at the natural resonance frequency. As a result, the electrostrictive vibrator continues to vibrate permanently, the three-terminal switching element continues to turn on and off, and due to the on and off operation of the three-terminal switching element, the current flowing through the inductive ballast is unique. Intermittent at the resonant frequency, high voltage pulses are generated across the inductive ballast depending on the natural resonant frequency. Thereby, the lighting state of the discharge lamp is maintained.

Example FIG. 1 is an electrical circuit diagram of a discharge lamp device according to the present invention.

In the figure, 1 is an AC power supply such as a commercial AC, 2 is a power switch, 3 is a rectifier circuit, 4 is a smoothing capacitor, 5 is an inductive ballast, 6 is a discharge lamp, 7 is a three-terminal switching element, 8
is an electrostrictive vibrator. The inductive ballast 5 has one end connected to the power line (+
) side. The three-terminal switching element 7 is constituted by a transistor in this embodiment, and has its collector C connected to the intermediate tap P1 of the inductive ballast 5.
The emitter E is connected to the power supply line (
-) side. 9 and 10 are resistors connected to the base B, which is the control electrode of the three-terminal switching element 7;
1 is a diode.

In this embodiment, the electrostrictive vibrator 8 is shown in FIGS.
As shown in the figure, a pair of drive electrodes 82 and 83 are formed on both sides of the disk-shaped element body 81 in the thickness direction, and a comparison of the electrode areas is made on the side on which the drive electrode 82 is formed. A four-terminal structure is used in which a small return electrode 84 is formed and a high voltage output electrode 85 is further formed on the outer periphery. Then, the drive electrodes 82 and 83 are inserted and connected to the power supply lines (+) and (-) so as to be in series with the inductive ballast 5, and the return electrode 84 is connected to the control electrode of the three-terminal switching element 7. It is connected to the B side to form a feedback circuit from the electrostrictive vibrator 8 to the three-terminal switching element 7. Further, a discharge lamp 6 is connected between the high voltage output electrode 85 and the drive electrode 83.

FIG. 4 is a diagram showing a general equivalent circuit of the electrostrictive vibrator 8.
Between the drive electrodes 82 and 83, there are static capacitances Cd and L during non-resonance.
This is an equivalent circuit in which the CR natural resonance system is connected in parallel. The static capacitance Cd approximately corresponds to the capacitance between the drive electrodes 82 and 83, and the LCR natural resonance system is unique to the electrostrictive vibrator.

The electrostrictive vibrator 8 has a natural resonance frequency fO determined by the LCR natural resonance system.

In the above circuit configuration, when the power switch 2 is closed and the AC power supply 1 is turned on, the DC voltage that has been rectified and smoothed by the rectifier circuit 3 and the smoothing capacitor 4 is instantaneously electrostricted through the inductive ballast 5. Drive electrode 82 of vibrator 8
-83. At this time, the electrostrictive vibrator 8 has a capacity of 1c.
In addition to acting as a capacitor due to d, it also produces a mechanical strain proportional to the applied electric field. FIGS. 5(a) to 5(d) are diagrams showing the vibration state of the electrostrictive vibrator 8 at this time. The strain oscillator 8 expands as shown in FIG. 5(b) by the first voltage application by closing the power switch 2, and thereafter, due to its elastic vibration, the strain oscillator 8 expands as shown in FIG. 5(C) and ( d) causes a transient vibration as shown in FIG. When a mechanical strain is applied to the electrostrictive vibrator 8, an electrostrictive phenomenon occurs in which a charge corresponding to the strain is generated. Therefore, due to the transient vibration, the feedback electrode 84 has an electric charge corresponding to the vibration strain. electric charge is induced. Here, by making the self-inductance value L1 of the inductive ballast 5 and the value of the atomization Cd between the drive electrodes 82-83 approximately equal to the natural resonance frequency of the electrostrictive vibrator 8, the return electrode 84 is , as shown in FIG. 6, a signal corresponding to the natural resonant frequency fO of the electrostrictive vibrator 8 can be generated.

The signal with the natural resonance frequency fO generated in the feedback electrode 84 as described above is fed back to the control electrode B of the three-terminal switching element 7, so the three-terminal switching element 7 is turned on and off at this natural resonance frequency fo. be done. As a result, the electrostrictive vibrator 8 continues to vibrate permanently, the three-terminal switching element 7 continues to operate on and off, and the on and off operations of the three-terminal switching element 7 cause the inductive ballast 5 to The flowing current is interrupted at the natural resonant frequency fO, and a high voltage pulse is generated across the inductive ballast 5 depending on the self-inductance L+ and the rate of time change of the current.

This high voltage pulse is applied to the drive electrodes 82-83 of the electrostrictive vibrator 8.
A voltage is applied between the high voltage output electrodes 8 and drives the high voltage output electrodes 8
5 and drive electrode 83, the voltage is applied to both ends of the discharge lamp 6, and the discharge lamp 6 is lit and its lighting state is maintained.

As described above, in the present invention, the resonance characteristics of the electrostrictive vibrator 8 are used to turn on and off the current flowing through the inductive ballast 5 at the natural resonance frequency fO, so the operating frequency can be changed. It is set in a high frequency range far higher than the conventional commercial frequency, for example, several tens of KHz, making the inductive ballast 5 smaller and lighter, improving lighting efficiency, simplifying the circuit configuration, and significantly reducing the number of circuit components. It is possible.

FIG. 7 is an electrical circuit diagram of another embodiment of the discharge lamp device according to the present invention. In this embodiment, the electrostrictive vibrator 8 has a three-terminal structure in which drive electrodes 82 and 83 are formed on both sides of the element body 81 in the thickness direction, and a high voltage output electrode 85 is provided on the outer peripheral surface. , a feedback transformer 13 is connected in series to this electrostrictive vibrator 8, and the feedback transformer 1
Feedback is applied to the control electrode B of the three-terminal switching element 7 via the three-terminal switching element 7.

Effects of the Invention As described above, according to the present invention, by utilizing the resonance characteristics of an electrostrictive vibrator and turning on and off the current flowing through the inductive ballast at its natural resonant frequency, the operating frequency is lower than that of the conventional one. By setting it in a high frequency range, for example, several tens of KHz, which is much higher than the commercial frequency of A discharge lamp device can be provided.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram of a discharge lamp device according to the present invention, FIG. 2 is a perspective view of an electrostrictive vibrator, FIG. 3 is a sectional view thereof, and FIG. 4 is an electrical equivalent circuit diagram thereof. Figure 5 (a) - (
FIG. 6 is a waveform diagram of a feedback signal, and FIG. 7 is an electric circuit diagram of another embodiment of the discharge lamp device according to the present invention. i-・Fist AC power supply 2-・・・Power switch 3・・Rectifier circuit 4・・・Smoothing capacitor 5・・Inductive ballast 6・・・Discharge lamp 7h-・・Three terminal switching element 8・・Electric power Strain oscillator 81...Element body 82.83...Drive electrode 84 fist/Φ return electrode 85...High voltage output electrode Fig. 2 Fig. 3 Fig. 4 Fig. 6 Fig. 5

Claims (3)

[Claims] (1) A discharge lamp, an inductive ballast that generates high-voltage pulses to drive the discharge lamp, and a three-terminal switching element that turns on and off the current flowing to the inductive ballast, in parallel with the discharge lamp. and an electrostrictive vibrator connected in series to the inductive ballast, and a vibration signal generated due to the electrostrictive phenomenon of the electrostrictive vibrator to the three-terminal switching element. A discharge lamp device comprising a feedback circuit for feeding back to a control electrode. (2) The electrostrictive vibrator includes a drive electrode connected to the inductive ballast, a high voltage output electrode that supplies high voltage pulses to the discharge lamp, and a feedback electrode connected to the control electrode of the three-terminal switching element. The discharge lamp device according to claim 1, characterized in that the discharge lamp device has an electrode. (3) The electrostrictive vibrator has a drive electrode connected to the inductive ballast and a high voltage output electrode that supplies high voltage pulses to the discharge lamp, and the drive electrode of the electrostrictive vibrator 2. The discharge lamp device according to claim 1, further comprising a transformer constituting a part of the feedback circuit connected in series with the feedback circuit.