JPS5933799A - Device for firing discharge lamp - 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 The present invention relates to (1) a reset device for a protection circuit that protects a lighting circuit from an abnormal state in which a discharge lamp undergoes rectified lighting.

FIG. 1 is a circuit diagram showing the configuration of a conventional discharge lamp lighting device, and FIGS. 2 to 5 are waveform diagrams for explaining the operation of this circuit diagram.

In FIG. 1, a DC power source (1) is, for example, an AC power source (2
) AC voltage is rectified by a rectifier (31) and smoothed by a smoothing capacitor (4), or a well-known battery.

This is a pulsating current power source that simply rectifies an AC power source, and (5) is a self-oscillating transistor inverter circuit equipped with a resonant circuit that converts the power of this DC power source (1) into high-frequency power. This is a lighting circuit that lights a certain fluorescent lamp (6). Further, αj is a protection circuit that protects the lighting circuit (5) from rectified lighting that occurs when the fluorescent lamp (6) reaches the end of its service life.

Next, the configuration of the discharge lamp lighting circuit (51) will be explained.

The positive terminal of the DC power supply (1) is connected to the high frequency choke coil (8
) through the output transformer (71), a pair of primary windings (71
a).

(7b), and the negative terminal of the DC power supply (1) is connected to the emitters of a pair of transistors (9a) and (9b). These transistors (9a), (9b
) is connected to both ends of the base winding (7c) of the output transformer (7), and each base resistor (1
0a) and (10b) are connected to the resistor 111. The collectors of the transistors (9a) and (9b) are connected to one end of the primary windings (7a) and (7b), respectively, and between the collectors of both transistors (9a) and (9b).

A resonance capacitor 02 is connected.

In addition, the output transformer (7) is of a leakage type, and the primary winding (
7a), (7b), In addition to the base winding (7c), secondary windings include an output winding (7d), an electrode winding (7e),
(7f) and a detection winding (7g). The output winding (7d) is for lighting the fluorescent lamp (6) as a discharge lamp.

The electrode windings (7e) and (7f) are polarized (6a) and (6b).
) for preheating and heating. Furthermore, the detection winding (7g) is only for detecting an abnormal state caused by the rectified lighting.

Next, the configuration of the protection circuit 0 will be explained. The detection winding (7
The cathode of a voltage regulator diode (15) is connected to the positive output terminal of the rectifier OI which full-wave rectifies the high frequency voltage of g), the resistor 061 is connected to the anode of the rectifier OI, and the resistor 061 is connected to the other end of the resistor t+61.
3) Connect the resistor (171 and resistor 081, and connect the capacitor t
l? The other end of l is connected to the negative output of rectifier II4. On the other hand, the other end of the resistor 08+ is connected to the base of the transistor 08+. The collector of transistor 09 is connected to the positive terminal of the DC power supply (1) via the resistor (Ill).
The emitter is connected to the negative output of the rectifier +141, and the negative output of the rectifier circle is connected to the negative terminal of the DC power supply (1).

Next, the operation of the discharge lamp lighting device (5) configured as two or more will be explained. When the DC power supply (1) is applied, this DC voltage is applied to the harmonic choke coil (8) and the primary winding i! It is applied between the collector and emitter of the transistors (9a) and (9b) through i (7a) or (7b). At the same time, the positive terminal of the DC power supply (1) is connected to the transistor (9
A base current is supplied to a) and (9b).

At this time, due to a slight imbalance between the two circuits, a collector current begins to flow to either one of the transistors (9a) or (9b), and due to the action of the base winding (7c) (4), the discharge lamp lighting circuit ( 5) performs self-excited oscillation operation, and each winding of the output transformer (7) has a frequency of, for example, 20KHz to 40KH.
Generates a high frequency voltage of about z.

By the way, Fig. 2(a), Fig. 3(a), Fig. 4(a)
The waveforms of the DC power supply (1) are shown in Fig. 2(b) and Fig. 3(b).
), FIG. 4(b) shows the high-frequency voltage waveform of one winding on the secondary side of the output transformer (7), and the dash-dotted line shows their envelope waveform, Vl, V2 . V3 indicates each peak voltage value.

Figure 3 shows a no-load state or a preheated state in which the fluorescent lamp (6) is not lit and the electrodes (6a) and (6b) are heated; ) is normally lit, the high-frequency voltage value in FIG. 2(b) and the voltage value in FIG. 3(b) are approximately 2-%, although this varies depending on the type of fluorescent lamp (61).

The reason for this large difference is that when starting the discharge lamp (6) with a high-frequency power source, the starting voltage increases compared to when starting with a commercial frequency power source, and the rate of increase at low temperatures increases. (5) Since the output winding (7) is a leakage type, the no-load voltage of the output winding (7d) should be set high, and the fluorescent lamp (6)
This is because when the lamp is turned on, the voltage of the output winding (7d) becomes the lamp voltage of the fluorescent lamp (6), and its value is almost the same as when the lamp is turned on with a commercial frequency power source.

Therefore, while the fluorescent lamp (6) is on, the electrode (6a) +
(6b) from 3.4■ to 4.2 like a conventional ballast
Electrode winding (7e), so that a voltage of about
When the voltage value of (7f) is set, in the preheated state, the electrode windings (7e), (7f) and the electrodes (6a), (6b)
An abnormal condition occurs in which excessive current flows.

In addition, as mentioned above, since the no-load voltage of the output winding (7d) is set high, an abnormal condition occurs in which the fluorescent lamp (6) rectifies and lights up at the end of its life. In each winding on the side, as shown in Fig. 4(b), a voltage as high as or higher than that in Fig. 3(b) is generated with one polarity, and as shown in Fig. 2(b) with the other polarity. The voltage value is low as shown in b).

Next, the operation of the protection circuit α3 when the abnormal condition occurs in the apparatus shown in FIG. 1 will be explained.

Now, the abnormal condition shown in Figure 3 or Figure 4 occurs at time (6) (zo), and the peak voltage value V is applied to the detection winding (7g).
If a high frequency voltage of D2 is generated, the rectifier FI41
A pulsating voltage shown in FIG. 5(a) is generated by full-wave rectification of this voltage at the output. However, for the preheating state shown in FIG. 3, the rectifier 041 may be capable of half-wave rectification. Here, if the peak value of the high frequency voltage generated in the detection winding (7g) when the fluorescent lamp (6) is normally lit is VDI, then the Zener voltage VZI of the constant voltage diode αω is expressed as (VDI < VZI < By setting an appropriate value in the range of VD2), the capacitor 0η is charged from time (to) via the constant voltage diode 051 and the resistor Oe.

The voltage waveform across this capacitor α is as shown in FIG. 5(b). The voltage of this capacitor (171) is applied between the emitter and base of transistor 09, and reaches the on-voltage of transistor 0 at time (11), and the voltage of this capacitor (171) is applied between the emitter and base of transistor 09. The base current that was flowing through the base resistors (10a) and (10b) now flows to transistor 0!J, the oscillation of the inverter stops, and each winding voltage on the secondary side of the output transformer (71) becomes zero. Therefore, charging of the capacitor (17+) stops.

(7) FIG. 5(C) shows the collector-emitter voltage waveform of the transistor αl.

Thereafter, the electric charge accumulated in the capacitor αη during the time (To) is discharged as the base current of the transistor α00 through the resistor, keeping the transistor i11 on. Then, at time 9 (t2), when the voltage of the capacitor (1) reaches the off-voltage of the transistor, the base current starts to be supplied to the transistors (9a) and (9b) again, and the peak value is again applied to the detection winding (7g). A high-frequency voltage of VD2 is generated.Then, since the capacitor αη is at the off-state voltage of the transistor 0gI, the high-frequency voltage continues to be generated for a time (T2) shorter than the time (To). Then, the DC power supply () is turned off or the fluorescent lamp (6) is turned on normally and the peak voltage value of the detection winding (7g) becomes the Zener voltage V of the constant voltage diode Q51.
As shown in Figure 5, the period (T+
+T2), the abnormal state and the state where this abnormal state is stopped are repeated.

By the way, when the fluorescent lamp (6) switches on and off at the end of its life, the inverter starts to cut off the oscillation operation (8) and the fluorescent lamp blinks. Therefore, when this lighting device is used in a house where one lighting fixture is generally installed in one room, when the fluorescent lamp (6) reaches the end of its lifespan and is turned on at night when the lighting is used, the protection circuit (131) is activated. Although it is possible to prevent damage to the fluorescent lamp (6) and malfunction of the lighting device, the fluorescent lamp (6) will flicker.In addition, in general homes, spare fluorescent lamps (6) are prepared. Few households purchase fluorescent lamps (6) and keep them in the room where the fluorescent lamps (6) are installed until they are replaced.
The drawback was that it could not be used with the light on.

This invention was made to eliminate the above-mentioned drawbacks.
The purpose of this is to stop the operation of the protection circuit when it operates at the end of its life, and to provide temporary illumination by continuously rectifying and lighting the borrowed light for a short period of time.

Hereinafter, details of the present invention will be explained according to Examples.

FIG. 6 is a circuit diagram showing one embodiment of the present invention. When explaining the configuration in FIG. 6, the same or corresponding parts as in FIG. 1 will be given the same reference numerals and the explanation thereof (9) will be omitted, and the parts different from those in FIG. 1 will be mainly described. As is clear from comparing Figure 6 and Figure 1,
A reset circuit is added to the protection circuit Q31 in FIG. 1. The reset circuit (branch) connects the anode of the diode (2) to the positive output terminal of the rectifier, connects its cathode to the negative output terminal of the rectifier via the capacitor (to), and connects the cathode of the diode (2) and the capacitor. Connect the anode of the thyristor to the connection point inside, and connect the cathode to the base of the transistor ■ via the resistor (c).

In addition, the anode of the thyristor is connected to the gate of the thyristor via the resistive surface and the reset switch (to), and the collector of the transistor (a) is connected to the connection point between the resistor Oe and the capacitor α. The emitter is connected to the negative output of rectifier 041. Here, the reset switch (to) is configured to close only when an external operation part such as a handle or a pull string is operated.

Next, detailed operation will be explained. When the DC power source (1) is applied to the discharge lamp lighting device (5), as shown in FIG.
) The fluorescent lamp (6) is turned on in the same manner as in the conventional example. Here, when the fluorescent lamp (6) is rectified and turned on at the end of its life, the detection winding (7)
g), the voltage VD2 shown in FIG. 5 is generated in the same manner as in the conventional example, and the capacitor f171 is connected to the constant voltage diode 9.g) in the same way as in the conventional example. Charged through resistor ae.

The voltage across this capacitor αη is the transistor (lω
When the on-voltage is reached, the transistor is turned on.

The DC power supply has resistance αυ from ), and (II a), (
The base current that had been flowing through transistors (9a) and (9b) through transistor (l1b) now flows through transistor four, stopping the oscillation of the inverter, and the output voltage (
The voltage of each winding 71 becomes zero, the fluorescent lamp goes out, and the capacitor (1?) stops charging. After that, when the charge in the capacitor 071 is discharged and reaches the off-voltage of the transistor αη, base current is supplied to the transistors (9a) and (9b), the inverter oscillates, and the fluorescent lamp (6)
The rectifier lights up again.

Here, the operation of reset circuit 4 will be explained.

The protection circuit (1) is activated when the fluorescent lamp (6) is lit at the end of its life.
3 is operating and the fluorescent lamp (6) is repeatedly turned on and off (11), when the reset switch (to) is operated, the reset switch (to) closes and smooths the output of rectifier α4 in the air conditioner. A gate current is supplied from the DC voltage to the thyristor via the resistor □□□. The thyristor conducts, supplies base current to the transistor through the resistive end, and turns on the transistor. When the transistor (A) is turned on, the charge on the capacitor (17+) is discharged, and the transistor (9) is turned off.
The base current is supplied to a) and (9b), and the inverter starts oscillating. Even if the reset switch example is opened, the thyristor is set so that a current higher than the holding current flows through it, so the thyristor and transistor ■ remain on and the transistor OI remains off.
The inverter also operates accordingly, and the fluorescent lamp (6) continues to light even though it is rectified lighting. Therefore, the room can be temporarily illuminated.

Next, when the DC power supply (1) is turned off in order to turn off the fluorescent lamp (6), the inverter stops oscillating. At this time, the current flowing through the thyristor is discharged in the capacitor (12).As the current is completed, the holding current decreases, and the thyristor (support)
is off. Therefore, when the DC power supply (1) is applied to turn on the fluorescent lamp (6) again, the thyristor is off, so the protection circuit α3 operates, and the fluorescent lamp (6) is activated.
61 repeats turning on and off.

Here, in the initial period when the fluorescent lamp (6) starts normally lighting and starts rectifying lighting at the end of its life, there is no chance that the fluorescent lamp (6) will be damaged or the lighting device (5) will malfunction due to abnormal voltage, etc. There is no change in the light generated by the fluorescent lamp (6) compared to when it is normally lit. Therefore, no inconvenience will occur if the lights are turned on for a short period of time only at night, as is the case in ordinary houses. Further, by turning on the DC power supply (1) and repeating the turning on and off of the fluorescent lamp (6) until the reset switch (2) is operated, it is possible to notify that the fluorescent lamp (6) has reached the end of its life. Furthermore, even if the reset switch ■ is operated to continuously rectify the lighting, once the DC power supply (1) is turned off and the fluorescent lamp (6) is turned off, when the DC power peak is applied again, the protection circuit α3 can also be made operational.

FIG. 7 is a circuit (13) showing another embodiment according to the present invention. It is a diagram.

Now, when the fluorescent lamp (6) is rectified and lit, the protection circuit 13 does not operate, and when the fluorescent lamp (6) repeatedly turns on and off, operate the reset switch (to) and the reset circuit When rectified lighting is turned on, the light generated by the fluorescent lamp (6) is almost unchanged from when it is normally lit, so it is designed to indicate that it is rectified lighting, and it is a resistance (to) 1 indicator. Light emitting diode 011゜ Constant voltage diode ■
A display circuit (to) consisting of a series circuit is added.

In other words, when the thyristor (to) is turned on by operating the reset switch ■ and the fluorescent lamp (6) is rectified and lit, the voltage generated in the detection winding (7g) is high, and the voltage across the capacitor is set to the constant voltage diode. Operation type (to) Current flows to the light emitting diode Gυ through the resistor end, causing the light emitting diode Cll to emit light. On the other hand, during normal lighting, the detection winding (7
g) Since the generated voltage is low and the voltage inside the capacitor is also low, even if the operation switch (support) is operated, the light emitting diode Gl
l does not emit light.

By the way, in the above description of the embodiment, the inverter of the discharge lamp lighting (14) device (5) is a self-excited oscillation push-pull transistor inverter, but other types of inverters, such as a one-way type inverter or a separately excited type inverter, may be used.

In addition, output drance (
The change in the winding voltage of 71 is detected.

Other methods, such as those that detect overcurrent or those that detect changes in frequency, may also be used. Furthermore, although the protection circuit 0j is exemplified as one that causes the fluorescent lamp (6) to blink when an abnormality is detected, other types of protection circuits such as those that turn off the fluorescent lamp (6) or dim the fluorescent lamp (6) are illustrated. It can be anything.

As described above, according to the present invention, when a fluorescent lamp reaches the end of its lifespan and is rectified and lit, a reset circuit of a protection circuit is provided which protects the lighting circuit by changing the operation of one lighting circuit. This has the effect of allowing you to temporarily turn on the fluorescent lamp if you do not have spare parts for the fluorescent lamp or cannot immediately replace the rectified wall lamp when the fluorescent lamp is turned on. .

[Brief explanation of the drawing]

(15) Fig. 1 is a circuit diagram showing the configuration of a conventional device, Figs. 2 to 5 are waveform diagrams for explaining the operation of the discharge lamp lighting device of Fig. 1, and Fig. 6 is a circuit diagram showing the configuration of a conventional device. FIG. 7 is a circuit diagram showing the structure of another embodiment of the present invention. In the figure, (1) is a DC power supply, (5) is a lighting circuit, and (6) is a lighting circuit.
) is the discharge lamp, αl is the protection circuit, Ya is the reset circuit, G
11l is a display. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Makoto Kuzuno - (16) Commissioner of the Japan Patent Office 1. Display of incident Patent application No. 57-142403 2
, Title of the invention: Discharge lamp lighting device 3, Relationship with the case of the person making the amendment Patent applicant address: 112-3 Marunouchi 2-chome, Chiyoda-ku, Tokyo
Name (601) Mitsubishi Electric Corporation Representative Hitoshi Katayama 4, Agent address Mitsubishi Electric Corporation 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (6699) Patent attorney Shin Kuzuno
- (Contact No. 03 (213) 3421 Patent Department) (1) 5. N4 Positive subject claims fi+ A lighting circuit for a discharge lamp, which changes the operation of the lighting circuit during rectified lighting of the discharge lamp, A discharge lamp lighting device comprising: a protection circuit that protects the lighting circuit; and a reset circuit 7 that stops the operation of the membrane protection circuit by external operation and causes the lamp to be lit continuously. (21) The discharge and lamp lighting device according to claim (1), characterized in that the reset circuit returns to the state before operation by deenergizing the lighting circuit. (3) Reset circuit Claim (1) characterized in that the device is provided with an indicator indicating that the device is in an operating state.
Item 21: Discharge lamp lighting device according to item 21.

Claims (3)

[Claims] (1) A lighting circuit for the discharge lamp, a protection circuit that protects the lighting circuit by changing the operation of the lighting circuit during rectified lighting of the discharge lamp, and a protection circuit that protects the lighting circuit by stopping the operation of the protection circuit by external operation. A discharge lamp lighting device equipped with a reset circuit that allows continuous rectification and lighting of electric lamps. (2) The discharge lamp lighting device according to claim 11+, wherein the reset circuit returns to the state before operation by deenergizing the lighting circuit. (3) The discharge lamp lighting device according to claim (1) or (2), further comprising an indicator indicating that the reset circuit is in an operating state.