JPS63307695A - Discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To reduce the generation of electric noise and deterioration of wiring after the quenching by repeating the igniting operation with the time sufficient for the initial start of a high-pressure discharge lamp in the time sufficient for the restart of the high-pressure discharge lamp. CONSTITUTION:The first timer TM1 measuring the time sufficient for the initial start of a high-pressure discharge lamp DL and enabling an igniter IGN only during the measured time, the second timer TM2 repeatedly operating the first timer TM1, and the third timer TM3 prohibiting the operation of the igniter IGN after the measured time elapses are provided. When a luminescent lamp is restarted from the hot state after quenching occurs while the high-pressure discharge lamp DL is continuously lit, starting high-voltage pulses occur intermittently. An adverse effect to the acoustic equipment and computer equipment due to the occurrence of electric noise can be thereby reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a discharge lamp lighting device whose load is a high-pressure discharge lamp that requires a high-pressure pulse for starting.

(Background Art) FIG. 5 is a circuit diagram for explaining the principle of a conventional high pressure discharge lamp lighting device. A high-pressure discharge lamp DL is connected to the AC power source vI via a choke coil L, which is a current-limiting element. The choke coil L1 has a tap in the middle of the winding, and the zero windings N1 and N2, which also serve as a pulse transformer for generating a high-voltage pulse for starting the high-pressure discharge lamp DL, are connected to the pulse transformer, respectively. Corresponds to the primary winding and secondary winding. The primary winding N1 is connected to an AC power source v1 via a capacitor C1 and a triac Q1. A series circuit of a resistor R3 and a capacitor C7 is connected to both ends of the high pressure discharge lamp DL. Q2 is a voltage-responsive switching element that becomes conductive when the charging voltage of the capacitor C2 exceeds a predetermined value to trigger the gate of the triac Q.

The operation of the circuit shown in Section 5 will be briefly explained with reference to the waveform diagram of FIG. FIG. 6(a) shows the voltage across the high-pressure discharge lamp DL, and FIG. 6(b) shows the charging voltage of the capacitor C2, and the solid line shows the state of the high-pressure discharge lamp DL before starting,
The broken line indicates the state of the high-pressure discharge lamp DL during steady lighting.

Before starting the high-pressure discharge lamp DL, the power supply voltage of the AC power supply v1 is applied to both ends of the high-pressure discharge lamp DL (for convenience, it is assumed to be ■1).
A substantially equal voltage is applied to the capacitor C2, and the capacitor C2 is charged via the resistor R1 from the beginning of each half cycle of the power supply voltage V, and when the charging voltage of the capacitor C2 reaches the response voltage of the voltage responsive switching element Q1, Voltage-responsive switching element Q2 conducts, and the charge on capacitor C2 is discharged to the gate of triac Q, triggering triac Q1. By this, triac Q1
conducts, an open circuit is formed between the AC power supply V6, the primary winding N1 of the choke coil L1, and the capacitor C3, and a steep current flows through the primary winding N1, generating a pulse voltage. This pulsed voltage is also induced in the secondary winding N2, superimposed on the power supply voltage V, and applied as a starting high voltage pulse to both ends of the high pressure discharge lamp DL. From now on, the power supply voltage v
Until the end of this half cycle of 1, the voltage responsive switching element Q2 remains in a conductive state. Then, at the end of the half cycle, the polarity of the power supply voltage vl is reversed, so that the voltage responsive switching element Q2 becomes non-conductive. In the next half cycle of the power supply voltage VI, the above operation is repeated, and a high voltage pulse for starting is superimposed on the power supply voltage VI for the high pressure discharge lamp DL once in each half cycle of the power supply voltage V1. (See the solid line in Figure 6 (a)).

When the high pressure discharge lamp DL is started by the above-mentioned starting high voltage pulse, the voltage across the high pressure discharge lamp DL becomes as shown by the broken line in FIG. 6(a). In general, the voltage across the high-pressure discharge lamp DL in the lighting state is about half of the power supply voltage Vl, so the charging voltage of the capacitor C2 does not reach the response voltage of the voltage-responsive switching element Q2, as shown in FIG. ), and therefore, when the high-pressure discharge lamp DL is in the lighting state, the triac Q1 is not triggered and the high-voltage pulse for starting as described above is not generated.

The circuit shown in FIG. 5 operates as described above, and is a high-pressure pulse generation circuit for starting the high-pressure discharge lamp DL (
The so-called igniter IGN) stops operating only when the high-pressure discharge lamp DL is turned on. therefore,
Even if the high-pressure discharge lamp DL is disconnected from the discharge lamp lighting device (so-called no-load state), or even if the high-pressure discharge lamp DL is connected due to the life of the high-pressure discharge lamp DL, etc. , even if the high-pressure discharge lamp DL cannot shift to steady lighting, the igniter IGN continues to operate, and the high-pressure discharge lamp DL continues to operate while the AC power supply v1 is turned on.
A high voltage pulse is continued to be applied to both ends of the .

The operation of the igniter IGN for such a long time causes continuous generation of electrical noise, which increases the possibility of adverse effects on audio equipment and computer equipment. In addition, in the circuit shown in Fig. 5, a feed line li (so-called tube lamp circuit)
In such a case, there is a possibility that the feed wiring may deteriorate due to the continuous application of high voltage pulses generated by the igniter IGN, or in the worst case, burn out.

Therefore, instead of making the operation of the igniter IGN respond to the state of the high-pressure discharge lamp DL, it is conceivable to forcibly stop the operation of the igniter GN at a fixed time using a timer. By the way, in the case of a high-pressure discharge lamp, once it enters a steady lighting state, if it goes out for some reason (typically a momentary power outage), it will take, for example, about 5 to 20 minutes before it restarts. Generally required. This is because when a high-pressure discharge lamp is lit steadily, the arc tube becomes extremely hot, and the above-mentioned starting high-pressure pulse will not start the high-pressure discharge lamp until the arc tube temperature drops to a sufficiently low temperature. This is because it cannot be done. Therefore, it is appropriate to set the period of time required until the above-mentioned igniter IGN is stopped to be typically about 20 minutes. However, if the application of high voltage pulses is continued for as long as 20 minutes, the above-mentioned problems such as continuous generation of electrical noise and deterioration and burnout of the transmission wiring cannot be satisfactorily solved.

Therefore, a timer is provided to operate the igniter IGN only for a sufficient period of time for the initial starting of the high pressure discharge lamp DL (the initial starting is referred to as the "initial starting" to distinguish it from the above-mentioned restart immediately after the lamp goes out), and It is conceivable to periodically repeat the igniter operation. The operating time of the igniter IGN, which is sufficient for the initial starting of the high pressure discharge lamp DL, is typically 7 to 10 seconds.
For example, by returning the rope every two minutes, it is thought that the above-mentioned restart can be sufficiently coped with. However, even with this method, in the so-called no-load case, 7~
Intermittent electrical noise that lasts for 10 seconds will be repeated every 2 minutes, and as for the deterioration of the transmission wiring mentioned above, although the short-term effective stress will be reduced, it will continue to occur over a long period of time. There are aspects that cannot necessarily be said to be effective if the stress caused by the application of high-voltage pulses is integrated.

(Object of the invention) The present invention has been made in view of the above points,
The object thereof is to provide a discharge lamp lighting device that eliminates the inconvenience caused by continuous application of high-voltage pulses for starting a high-pressure discharge lamp.

(Disclosure of the Invention) In order to achieve the above object, the discharge lamp lighting device according to the present invention uses a high-pressure discharge lamp DL that requires a high-pressure pulse for starting, as shown in FIGS. 1 to 4. In a discharge lamp lighting device including the igniter IGN for generating high-pressure pulses as a load, a time sufficient for at least the initial starting of the high-pressure discharge lamp DL is measured, and the igniter IGN is enabled to operate only during the measured time. A first timer TM, a second timer TM2 that repeatedly operates the first timer TM, and a time sufficient for at least restarting the high-pressure discharge lamp DL, and after the elapse of the measured time, the above-mentioned Third timer TM that prohibits the operation of the igniter IGN
s.

That is, in the present invention, the above-mentioned difficulties are solved by making the pulse generation period the minimum possible value while making full use of each feature of the idea of forcibly canceling the application of high-voltage pulses. It is intended to achieve
The time required for the first start of the high pressure discharge lamp DL (typically 10
a first timer TM that measures the time (seconds);
A second timer TM is provided so that the timer TM operates intermittently at a fixed period (typically 2 minutes), and these first and second timers TM, , TM2 operate at least at a high pressure discharge lamp. Sufficient time to restart the DL (typically 2
A third timer TM3 is provided so that the igniter IGN operates for more than 0 minutes), and the igniter IGN is operated only during the time period of the first timer TM.
The igniter IGN is not operated after the elapse of the measured time period .

Therefore, in the present invention, when the arc tube of the high-pressure discharge lamp DL is restarted in a hot state after the high-pressure discharge lamp DL has been turned off due to some cause (for example, a momentary power outage) while the high-pressure discharge lamp DL continues to be lit, Also, since the high-voltage pulse generation for starting the high-pressure discharge lamp DL is performed intermittently, compared to the conventional method that generates high-voltage pulses continuously until the lamp is restarted, it generates electrical noise that can cause damage to audio equipment and computer equipment. In addition, the possibility of deterioration or burnout of the feed wiring (so-called tube lamp circuit) between the igniter IGN and the high-pressure discharge lamp DL can be reduced. Not only that, but the high-pressure discharge lamp DL cannot be started for the first time or restarted!
(For example, even if the ball runs out), the timer TM3
Due to the presence of <I! It will never be continued.

Examples of the present invention will be described below.

FIG. 1 is a circuit diagram of an embodiment of the present invention. In the circuit of FIG. 1, parts having the same functions as those of the conventional example of FIG. 5 are given the same reference numerals and redundant explanations will be omitted.

The power supply voltage of the AC power source v1 is stepped down by the power transformer Tf, rectified and smoothed by the full-wave rectifier circuit DEI+ and the capacitor C3, and then is converted into the first to third timers TM+~
The control power supply voltage of TM3 is obtained.

The first timer TM is a general-purpose timer ICt-1 (
For example, NEC μPC1555) and this timer I
It is composed of resistors R, , , R,2 and capacitors C, , , C, , C, 3 which are control elements of Ctm+.

The second timer TM is a general-purpose timer IC1-2 (
For example, National AN6780) and this timer I
Resistor R21 and capacitor Ca, which are control elements of Ctmt
r, C2□.

The third timer TMs is a general-purpose timer ■Ctm
s (for example, National AN6780), resistors R3+ and R32, which are control elements of this timer ICtm, and capacitors C311C3!1c33.

The AC side terminal of the full wave rectifier circuit DB is connected to the trigger capacitor C2 of the triac Q1, and the aforementioned first timer TM is connected to the DC side terminal of the full wave rectifier circuit DB.
The output end of is connected.

A trigger for starting the operation of the timer TM is performed by the output of the second timer TM, and a trigger for starting the operation of the timer TM is performed by the output of the third timer TM.

FIG. 2 is an operational waveform diagram for explaining the operating status of the igniter IGN in the circuit shown in FIG.

FIG. 2(A) is a waveform diagram of the output signal of the timer TM3 obtained from the output terminal (pin 6) of the timer ICtm. Timer TM until fixed time t3
, which indicates that the output signal of , is being generated.
For Ct@3, the stop terminal (pin 2) is “14high”.
” level, the reset terminal (pin 3) is “High”
It oscillates under the condition of level, and the reset terminal (pin 3) is connected to the output terminal (bin 6), so after the power supply voltage V is turned on, the output terminal (bin 6) is output at time t3.
The oscillation is stopped when the signal becomes "Lo-" level, and this state is maintained thereafter.

FIG. 2 (b) is a waveform diagram of the output signal of the timer TM2 obtained from the output terminal (pin 6) of the timer ICtm2, and shows that the values of the resistor R21 and the capacitor C22 after the power supply voltage 1 is turned on. The stop terminal (pin 2) is always at the ``) (high@ level, indicating that the output signal is generated with the oscillation period T2 determined by until “High”
″Maintain the level.

FIG. 2(C) is a waveform diagram of the output signal of the timer TM obtained from the output terminal (pin 3) of the timer ICtm+, in which the timer ICts is output after the power supply voltage v1 is applied.
Every time the trigger terminal (pin 2) of l falls to the "Low" level, the resistor R1! This indicates that the output signal is at the "High" level at the time T1 determined by the value of the capacitor CI2.
The output of CL Tsuru 2 is at "High" level, but the resistor R
5, and due to the presence of capacitor C8, capacitor C1l
Since the terminal voltage of V is at the "Low" level for an extremely short period of time (until the capacitor C11 is charged to 1/3 or more of the power supply voltage of timer ICtm1), immediately after the power supply voltage V is turned on, timer ICLm+ is triggered, and the output terminal (pin 3) of the timer I Ctml becomes "High" level during a time T.

The timers TM, ~TMs of the circuit in FIG. is “L”
ow" level period, due to the existence of a bypass circuit between the output terminal (pin 3) and the ground terminal (pin 1) of the timer ICtml, both ends of the capacitor C2 are shorted, and the resistance Capacitor C2 is not charged through R8, and the charging voltage of capacitor C2 does not increase. Therefore, triac Q1 maintains a non-conducting state, and no matter what the state of high-pressure discharge lamp DL is, the high voltage for starting During the period in which no pulse is generated and the output of the timer T M + is at the "HiHh" level, the trigger circuit operates in the same manner as in the conventional example described above, and when the high pressure discharge lamp DL is started, At that point, the generation of high-voltage pulses for automatic operation of the high-pressure discharge lamp DL is stopped, and if the high-pressure discharge lamp DL is substantially removed from the lighting device, it is in a so-called no-load state. Also, the high-pressure pulse for starting the high-pressure discharge lamp DL occurs only during the period T1 in FIG. 2 (c), and moreover, at least after time 1° in FIG. No matter what state DL is in, the starting high voltage pulse is not generated.

Dai 13”- FIG. 3 is a circuit diagram of another embodiment of the present invention.

In this embodiment, parts having the same functions as those in the circuit shown in FIG.
The difference between this embodiment and the circuit shown in FIG. 1 is that in the circuit shown in FIG. In this circuit, a series circuit of resistor R and capacitor C2 is connected to both ends of AC power supply vl. If such a circuit configuration is adopted, under conditions where the high-pressure discharge lamp DL can be started both for the first time and restarted, the high-pressure discharge lamp DL will not start for at least the period determined by the timer TM after the high-pressure discharge lamp DL starts. A high-voltage pulse for starting the high-pressure discharge lamp DL is generated regardless of whether it has started or not, but if the high-pressure discharge lamp DL is unable to be started for the first time or restarted, the timer T M s
, T M x , T M + , the same operation as described above is performed.

In addition, in the circuit configuration of FIG. 3, the high pressure discharge lamp D is connected to the resistor R1.
Since a high voltage pulse for starting L is not applied, this is superior to the case where the circuit configuration shown in FIG. 1 is used in that there is no need to consider the withstand voltage of the resistor R1.

Tomogon Takumi 1 Figure 4 is a circuit diagram of yet another embodiment of the present invention. In this embodiment, parts having the same functions as the circuit in Figure 1 are given the same reference numerals and are duplicated. Explanation will be omitted. In the circuit shown in Figure 1, if the high-pressure discharge lamp DL goes out due to a momentary power outage of the power supply voltage
Although the timer TM3 is automatically reset, if the high-pressure discharge lamp DL goes out due to, for example, a sudden decrease in the power supply voltage v1, the timer TM3 is not reset.
The high pressure discharge lamp DL remains unlit until the AC power supply V is turned off once. In consideration of this point, the circuit shown in FIG. 4 has a timer TM and a glue set element A added to the circuit shown in FIG. 1.

The reset element A is configured to send a timer TM2 reset signal only when the high-pressure discharge lamp DL transitions from a lit state to an unlit state while the AC power supply v1 is turned on. Therefore, in the circuit of FIG. 4, the AC power supply V1
When the high-pressure discharge lamp DL shifts from a lit state to an unlit state while the lamp is turned on, it is possible to prevent the unlit state from continuing.

(Effects of the Invention) As described above, the present invention makes it possible to repeatedly perform the igniter operation for a sufficient time to start the high pressure discharge lamp for the first time within a time sufficient to restart the high pressure discharge lamp. This has the effect that restarting is reliably performed, and the possibility of electrical noise generation and wiring deterioration can be reduced as much as possible.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of one embodiment of the present invention, Fig. 2 is an operation waveform diagram of the same as above, Fig. 3 is a circuit diagram of another embodiment of the present invention, and Fig. 4 is a circuit diagram of an embodiment of the present invention.
This figure is a circuit diagram of still another embodiment of the present invention, FIG. 5 is a circuit diagram of a conventional example, and FIG. 6 is an operation waveform diagram of the same. DL is a high pressure discharge lamp, IGN is an igniter, and TM. ~TM is a timer.

Claims (1)

[Claims] (1) In a discharge lamp lighting device whose load is a high-pressure discharge lamp that requires a high-pressure pulse for starting, and which is equipped with an igniter for generating the high-pressure pulse, a time sufficient for at least the initial starting of the high-pressure discharge lamp is measured, and the measured time is a first timer that enables the igniter to operate only during the operation; a second timer that repeatedly operates the first timer; and a timer that measures at least enough time to restart the high-pressure discharge lamp; A discharge lamp lighting device comprising: a third timer that prohibits operation of the igniter after the elapse of time.