JPS61147498A - High pressure discharge lamp lighting 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 device for lighting high-pressure discharge lamps such as high-pressure sodium lamps and metal halide 2 lamps at high frequencies.

[Conventional device]

Attempts have been made to reduce the weight of a lighting device by lighting a high-pressure discharge lamp (hereinafter simply referred to as a lamp) at high frequency using an inverter.

An example of this type of device is the device disclosed in Japanese Patent Application Laid-open No. 111627/1983. Figure 4 shows this conventional device, and in Figure 9, (1) is a DC power supply, (2) is an inverter, (3) is a lamp, and the inverter (2) is connected to transistors (22a) and (22b) and a resonant circuit. It consists of a capacitor @, an output transformer G, etc. Since the output transformer (to) is configured as a leakage transformer, the current of the lamp (3) is set to a predetermined current value of this impedance transformer. When DC current m+1+ is applied, the transistors (22a) and (22b) have the following effects.

A pace current is supplied through the resistors (23a) and (23b), and the well-known self-excited perfecting operation starts due to the action of the feedback winding (to), and the secondary winding #( c) Generate a high frequency voltage. As a result, the lamp (3) discharges and lights up once. Here, inverter (2)
The frequency of the output voltage is the frequency/l until the lamp (3) starts discharging, and the frequency 1 after the lamp (3) is turned on.
2 changes and fl<f. This is possible because after the lamp is turned on, the concentric frequency of this inverter becomes a frequency determined approximately by the scale inductance on the secondary side of the output transformer.

If sufficient voltage is supplied to start lamp (3) K discharge, the output transformer (c) will require a large capacity and its shape will become large. A device that lights a lamp using a reactor, and uses a thyristor called a triac to ensure the lamp starts.

A device that applies high voltage is rare.

Japanese Patent Laid-Open No. 47-731466 discloses a conventional device of this type. Figure 5 shows this conventional device.
) is an AC power supply, (6) is a single-turn transformer, (7) is a bidirectional thyristor called a triac, and (8) is a choke coil as a stabilizer.

(9) is the triac trigger circuit, (91
is a high impedance element, and (3) is a lamp.In the device configured as described above, the voltage boosted by the autotransformer (6) from the AC power supply (5) is applied to the lamp (3).
) is applied to start awakening. This causes current to flow through the ballast (8).

The triac (7) is triggered to supply a predetermined current θL to the lamp (3). After the lamp is lit, a trigger current flows through the triac (7) every half cycle of the AC power supply (5), making it conductive. A trigger signal was required, and a special device was required for the trigger circuit in order to conduct the triac 360°.

In addition, if an inverter supplies a high enough voltage to start the lamp, there is a risk that the lamp will continue to abnormally discharge at the end of its life, or if a device that detects half-wave discharge and stops the inverter's output is a fluorescent lamp. 1986-5
No. 6199. Devices of this kind rarely simply stop and maintain the output, or stop for a short time and then start supplying high-frequency voltage again.

[Problem that the invention seeks to solve]

In conventional devices, the output transformer of the inverter has become large in order to start the lamp. Furthermore, if a high voltage is applied to ensure discharge, there is a risk that abnormal discharge will occur at the end of the lamp's life.

[Means for solving problems]

In addition to the secondary winding, a step-up winding is provided in the output transformer of the inverter (2), and a lamp is connected to the secondary winding via a switch. It also includes lamp lighting detection means, lamp abnormal discharge detection means, and inverter output stop means.

[Operation of means for solving the problem] Switch αQ is closed by detecting lighting of the lamp. If abnormal discharge is detected in this state, the output of the inverter is stopped for a predetermined period to prevent the lamp from being lit again in a short period of time.

[Embodiments of the invention]

Fig. 1 shows one embodiment of the device according to the present invention. In Fig. 9, (1) is a DC power supply, (2) is an inverter that performs self-oscillation, (3) is a lamp, and Ql is a triac as a switch, and an inverter that performs self-oscillation. υ is the impedance and the inverter (
The output transformer (c) of 2) is provided with a secondary winding (to) and a step-up winding (to).

The triac system is triggered by the output of the current transformer I which detects the lighting of the lamp (3). The output transformer (c) of the inverter (2) is a one-cage transformer, and the winding ω installed in the magnetic circuit on the secondary winding side detects abnormal discharge (half-wave discharge, etc.) of the lamp (3). When an abnormal discharge occurs in the winding, an output voltage is generated on the anode side of the constant voltage diode (107). Also, a constant voltage diode (46)
An output voltage is also generated on the anode side of the lamp (3) while the lamp (3) is lit. The AND circuit (105) transmits a trigger signal to the monostable multivibrator (106). Also,
(109) is an output stop device which stops the output of the inverter (2) during the time-limited operation of the monostable multivibrator.

Figure 2 shows an example of this output stop device.
The relay (111) is energized by the transistor (110), and the contact (108) is opened to stop the operation of the inverter (2).

In the device configured as described above, since the contacts (108) are normally open, the inverter oscillates as is well known and generates an output voltage in the output transformer (c).

Here, the voltage of the booster winding (3) is applied to the lamp (3), so that it is discharged. Then, the current transformer generates an output voltage,
Trigger the triac (II), make it conductive, and the voltage of the secondary winding (to) will pass through the triac (1G) to the lamp (3
). In this way, the lamp (3) is
Flow 1Lm.

When the lamp (3) is lit normally, the voltage of the winding ■ is low, but when half-wave discharge is performed, the half-cycle voltage of the lamp (3) becomes high, 1 winding + 11j! Since the voltage (2) also becomes high, the anode side of the constant voltage diode (107), that is, the input terminal of the AND circuit (105) becomes H level. Since the signal level of the two input terminals of the AND circuit (105) becomes H, the output of this circuit becomes H, triggering the monostable multivibrator (106), and shifts to a time-limited operation. During the time-limited operation period of the monostable multivibrator (106), the inverter (21) stops outputting. After that, the inverter starts operating again, but this time-limited operation period T was determined by the following experiment. Established.

FIG. 3 shows, as an example, the restart voltage measured after a high-pressure sodium lamp was turned off. Immediately after the lights go out, the restart voltage gradually increases and reaches its maximum around 60 seconds. stop【.

After about 10 seconds, the restart voltage will be high enough9.
Even if the voltage required for normal starting is applied, the discharge will no longer start.゛Therefore, the time-limited operation period 1
By setting `` to approximately 15 seconds or more, it is possible to prevent the lamp from frequently discharging, which causes abnormal discharge such as at the end of the bow.

Also, to prevent this AND circuit from erroneously producing an output during the unstable operation period at the beginning of lamp discharge or otherwise.

A delay circuit such as an integrating circuit is provided for at least one of the lamp lighting detection signal or the abnormal discharge detection signal,
After the lamp's release starts.

The signal may be applied to the AND circuit after a predetermined period has elapsed.

The device of the present invention can also be applied when the DC power source (1) periodically causes a pause period in the lamp current, such as when the DC voltage is pulsating.

To be more reliable, in the example of the device shown in FIG. 1, the output stop device (109) may be operated when a signal is continuously generated at the output of the AND circuit for a predetermined period of time.

In the embodiment, a triac was used as the switch (I), but other semiconductor switching elements or mechanical switches such as relays may also be used.

The inverter is not limited to the one in the embodiment, and other types may be used, and the means for detecting abnormal discharge of the lamp is not limited to the one in the embodiment. Furthermore, stopping the output from the inverter (2) to the lamp is not limited to the device using the relay of the *embodiment, and any device that can stop the output may be used.

〔Effect of the invention〕

According to the device of the present invention, the lamp can be reliably lit without significantly increasing the capacity of the output transformer of the inverter, and when the lamp has abnormally discharged, the output of the inverter can be reduced until it becomes difficult to restart the lamp. Stopped to increase safety.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing one embodiment of this device. Figure 2 is a circuit diagram of the output stop device, Figure 3 is a restart characteristic diagram of a high-pressure discharge lamp, Figure 4 is a circuit diagram of a conventional device, and Figure 5
The figure is a circuit diagram of another conventional device. In the figure, the symbol (1) is the DC power supply, (21 is the inverter, I is the output transformer, @the secondary winding, ■ is the step-up winding. (3) is the high-pressure discharge lamp, (IG is the switch, riυ
is an inductance, ■ is an abnormality detection means, (41) is a lighting detection means, and (109) is an output stop device.

Claims (3)

[Claims] (1) In a device equipped with an inverter that converts DC voltage into high-frequency voltage and supplies high-frequency current to a high-pressure discharge lamp, the inverter is provided with an output transformer having a secondary winding and a step-up winding, and the secondary Through the switch to the winding,
Connecting the lamp and connecting the lamp to the step-up winding via an indance, detecting the lighting state of the lamp, and closing the switch with a lighting signal,
lighting detection means for superimposing the output of the secondary winding on the output voltage of the step-up winding and applying it to the lamp; an abnormality detection means for similarly detecting abnormal discharge of the lamp; A high-pressure discharge lamp lighting device comprising: an output stop device that stops the output of the inverter. (2) Time to stop the output supply of the above inverter is 1
The high-pressure discharge lamp lighting device according to claim 1, characterized in that the lighting time is set to 0 seconds or more. (3) The high-pressure discharge lamp lighting device according to claim 1 or 2, wherein the switch is constituted by a bidirectional thyristor. (4) Either one of the lighting detection means and the abnormality detection means. 4. The high-pressure discharge lamp lighting device according to claim 1, wherein the output signal of the two output signals is delayed, and the logical product of both output signals is input to an output stop device.