WO1993023976A1

WO1993023976A1 - Apparatus for lighting fluorescent lamp

Info

Publication number: WO1993023976A1
Application number: PCT/JP1992/000613
Authority: WO
Inventors: Hideo Sugimori
Original assignee: Alco Giken Co., Ltd.
Priority date: 1992-05-14
Filing date: 1992-05-14
Publication date: 1993-11-25
Also published as: AU1696592A

Abstract

A lighting apparatus of an electronic circuit, which is substituted for an ordinary glow lamp, and lights a discharge lamp fitted with filament electrodes such as a fluorescent lamp by causing satisfactory preheating current to flow through the filament electrodes and by giving a stable kick pulse between them, and is easy to be made into an integrated circuit. The apparatus is characterized by the following. It is a two-terminal network connected between two electrodes (P, Q) of a lamp (3). One terminal (Q) of the two terminals is a common electrode. It has a negative DC power supply (27) which is charged in the negative half cycles of an AC power supply. When the non-discharge of the lamp is sensed in a negative half cycle of the AC power supply, this is stored in the apparatus by utilizing the negative DC power supply. Thereby, a thyristor (5) connected between the two terminals is turned on and consequently a preheating current (I1) continues to flow through the filaments on and after a zero crossing point where the AC voltage shifts to the next positive half cycle. When the preheating current (I1) decreases under preset value (I0), reverse bias current is made to flow from the negative DC power supply to turn off the thyristor (5) and thereby to generate a kick pulse (Vk).

Description

Specification

`` Discharge lamp lighting device J

【Technical field】

The present invention relates to a discharge lamp with a filament, for example, a lighting device for a discharge lamp for lighting a fluorescent lamp.

[Background Art]

Conventionally, a glow lamp has been mainly used as a lighting device for a discharge lamp with a filament. However, a lighting device using a glow lamp has a short life because the glow lamp is a contact type and has a long life.In addition to replacing the glow lamp, manpower is required and the deterioration of the glow lamp leads to the deterioration of the discharge lamp. There is.

On the other hand, a discharge lamp lighting device using a semiconductor switch element has been proposed, but it has many problems and has not been put to practical use yet. For example, Japanese Patent Publication No. 56-140000 discloses an apparatus shown in FIG. However, in this conventional example, the lines connecting the lamp side and the lighting electronic circuit side are A, B, C and three terminals, and cannot be replaced with a global lamp.

In addition, since the non-discharge state is detected when the voltage between the lamp electrodes AB increases to a predetermined value in the positive half cycle of the AC power supply and the thyristor is turned on, the filament preheating current starts flowing. However, there is a disadvantage that it takes a long time to start lighting because the duty of the time for flowing the preheating current is restricted due to the late start time.

Furthermore, transfer AC power from positive to negative half-cycle, when the electric position of point C becomes negative, although turning off more thyristor to flow a reverse bias current 1 _2, rhino generally at turn-off The relationship between the anode current I, and the reverse bias current I ₂ at

I ₂ ^ (1/2 to 1/3) I, And the sensitivity to turn off varies. On the other hand, since the peak voltage V _k of the kick pulse generated by turning off is proportional to the anode current I, at the time of turning off, the voltage V _k of the kick pulse also varies. Therefore, it is necessary to adjust the value of the resistor R to compensate for these variations. The use of a variable resistor for the resistor R is an obstacle to miniaturization and requires adjustment work.

Furthermore, if lighting is attempted with insufficient preheating current, a higher kick pulse will be required.However, since the reverse bias current I ₂ is proportional to the power supply voltage V, the preheating current decreases when the power supply voltage decreases. In addition, both the kickball voltage and the lighting start time are long, or the lighting tends to be impossible.

DISCLOSURE OF THE INVENTION

On the other hand, the present invention solves all the problems of the prior art described above.

In the present invention, since the lamp side and the lighting circuit network are connected by two terminals, it can be used in place of a conventional glow lamp. In addition, the present invention performs non-discharge detection in a negative half cycle and sets a unidirectional switching element for flowing a preheating current, for example, a thyristor in advance so that the thyristor can be turned on. Since the preheating current is supplied immediately from the zero crossing point when the power goes from negative to positive, the preheating current can be supplied as long as possible from the zero crossing point to immediately before the next non-discharge detection. Moreover, since there is always Jode despite variations preheating current I, of the supply voltage magnitude at the time of turning off the thyristor, the magnitude of the voltage V _k of the kit Kuparusu is stable.

The most important feature that the present invention distinguishes from many prior arts is the two-terminal network connected between the two electrodes of the discharge lamp and at two terminals (P, Q). It has a negative DC power supply inside and uses this negative DC power supply to detect non-discharge during the negative half cycle of the AC power supply and control the unidirectional switching element. It is.

In order to facilitate understanding, the lighting device for a lamp according to the present invention includes an AC power supply (1), a choke coil (2) serving as a ballast, and a reference numeral in FIG. A discharge lamp with filament (3) is connected in series, and a capacitor for kick pulse generation (4) and a two-terminal network (terminals P and Q) are connected between both electrodes of the lamp (3). A discharge lamp lighting device that supplies a preheating current (II) to the above-described filament when turned on, and generates a kick pulse between both electrodes of the discharge lamp (3) when turned off. A directional switching element, for example, a thyristor (5), which is charged during one half cycle of the two terminals (P, Q), where one terminal (Q) is negative and the other terminal (P) is negative potential And a capacitor (27), which becomes a negative DC power supply, A non-discharge detection circuit that determines that the voltage between the two terminals (P, Q) is greater than a predetermined value (ed) and detects a non-discharge state of the discharge lamp; At the beginning of the next positive half cycle, the unidirectional switching element (5) is turned on to supply the filament with the preheating current (I,) and to release the non-compressed pack. It is characterized by having switching element control means for holding the off state of the unidirectional switching element (5) when the detection circuit detects the discharge state.

[Brief description of the drawings]

FIG. 1 shows an electric circuit diagram of one embodiment of the present invention.

FIG. 2 shows an equivalent circuit of the PUT 23 of FIG.

FIG. 3 shows a time chart of each part of the embodiment shown in FIG. 1. FIG. 4 shows an electric circuit diagram of another embodiment of the present invention. FIG. 5 shows a characteristic diagram of the positive characteristic thermistor 36 of FIG.

FIG. 6 shows a time chart of each part of the embodiment of FIG.

FIG. 7 is a characteristic diagram in which the discharge start time of the discharge lamp is represented by using the AC power supply voltage as a variable.

FIG. 8 shows a time chart when a temperature rise test is performed using an unlit lamp in the embodiment shown in FIG.

FIG. 9 shows a circuit diagram of a conventional example.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a circuit diagram of one embodiment of the present invention.

A series circuit of a choke coil 2 serving as a ballast and a discharge lamp 3 having filaments 3a and 3b is connected to a commercial AC power supply 1, and a series resonance with the choke coil 2 is performed in parallel with the discharge lamp 3 to cause a high voltage. The capacitor 4 for generating a kick pulse is connected.

Further, a two-terminal circuit network 13 described below is connected between both terminals P and Q of the discharge lamp 3.

To supply a preheating current to the filaments 3a and 3b of the discharge lamp 3 and to cut off this preheating current to generate a kick pulse until the discharge starts after the power is turned on. The filament preheating circuit consists of a series circuit of a thyristor 5 and a resistor 16 connected between the two terminals P and Q, and a resistor 15 that applies a control voltage to the gate electrode G of the thyristor 5. ing. This thyristor 5 is a thyristor with a unidirectional control electrode. The terminal P to which the anode electrode A is connected is the control side of the commercial AC power supply, and the other terminal Q is the common side. Therefore, the potential of the control terminal P is higher than the terminal Q in the positive half cycle of the commercial AC power supply, and the potential of the terminal P is lower than the terminal Q in the negative half cycle. The resistor 16 is provided to measure the current of the thyristor 5, substantially the preheating current I 1 of the lamp, and is proportional to the preheating current I, at both ends. A voltage drop e, occurs.

The preheating current measuring circuit is configured by connecting a series circuit of the resistor 18 and the emitter 17 and the base 8 of the transistor 17 to both ends of the resistor 16. The transistor 17 conducts while the terminal potential e, of the resistor 16 is higher than the base-emitter voltage V _{BB of the} transistor 17, and becomes non-conductive during a period when the terminal potential e, is low.

The negative DC power supply circuit detects the non-discharge state during the negative half cycle, and records the non-discharge state during the non-discharge state, and supplies the preheating current from the beginning of the next positive half cycle, It is provided for memory and control means for generating a kick pulse, recording the discharge pulse in the discharge state, and suppressing the preheating current and the kick pulse. This negative DC power supply circuit has a capacitor 27 connected between the common terminal Q and the negative power supply R, and a node A connected to the negative power supply R between the negative power supply and the control terminal P. A series circuit of a diode 26 and a high resistance 24, and a Zener diode 25 with a power source K connected to the common terminal Q between the force source K and the common terminal Q of the diode 26 It consists of.

The non-discharge detection circuit, which determines whether the electrode simple voltage of the discharge lamp 3 is greater than or less than the set value during the negative half cycle and detects whether or not the discharge is in a non-discharge state, is connected between the two terminals P and Q. It is composed of two divided voltage resistors 6 and 8 and a Zener diode 12 having an anode A connected to an intermediate connection point U between them. The non-discharge detection voltage e d is set by the zener voltage of the zener diode 12 and the two voltage dividing resistors 6 and 8.

When the non-discharge state is detected, the preheating current I, is set to the set current value I in the next positive half cycle. The memory means for storing data up to the limit is a programmable 'junction' transistor (PUT) 23 and a set circuit connecting this gate electrode G to the cathode K of the Zener diode 12. , And PUT It consists of a reset circuit that connects the cathode electrode K of 23 to the collector C of the transistor 17 for preheating current detection.

As shown in Fig. 2, the PUT 23 is a type of thyristor in which two transistors 28 and 29 are connected in positive feedback. When a negative current is applied to the gate of the PUT 23, that is, the base B of the transistor 28, the transistor 29 is turned on by the collector current, and another transistor 28 is turned on by the collector current. There is a function to turn on. To turn off PUT 23, set the anode-to-force node to 0 volts or reverse bias voltage. PUT 23 can be implemented by replacing the circuit shown in FIG.

Whether the above-mentioned storage means records the detection of the non-discharge state, or the preheating current I, is the set current value I. The OR circuit that detects whether the current exceeds the threshold value is connected to one end of the resistor 22 of the base circuit of the NPN transistor 20 and the power source of the PUT 23 and the collector C of the transistor 17. It is constructed by touching both sides. The collector C of the NPN transistor 20 is connected to the common terminal Q through the resistor 21, and the emitter E of the transistor 20 is connected to the negative power supply R.

In the thyristor control circuit for controlling the turn-on and turn-off of the thyristor 5, the base B is connected to the collector C of the NPN transistor 20 of the OR circuit, and the emitter E is connected to the negative power supply. The NPN transistor 19, the circuit 14 connecting the collector C of the transistor 19 to the gate electrode G of the thyristor 5, and the gate electrode for applying a control voltage to the thyristor 5 It consists of G and a resistor 15 connected to the anode electrode A. When the transistor 19 is cut off, the thyristor 5 is turned on at the zero crossing point when the half cycle changes from the negative half cycle to the positive half cycle, and the transistor 19 is turned on while the thyristor 5 is conducting. When turns on, thyristor 5 turns off.

Next, the operation of the embodiment shown in FIG. 1 will be described with reference to the time chart of FIG.

When the AC voltage V, is applied from the AC compress source 1 and a negative half cycle period is reached, a negative charging current flows through the capacitor 27 through the resistor 24 and the diode 26. However, the voltage at both terminals of the capacitor 27 does not exceed the Zener diode 25 Zener pressure. At the initial stage after the power supply is applied, the discharge lamp 3 is in a non-discharge state, the impedance between the electrodes of the discharge lamp 3 is high, and the voltage between P and Q changes as in the power supply 1 in the negative half cycle period. Eventually time t, the exceeds the set value e _d of the non-discharge detection circuit, divided by voltage at the resistor 6, 8 is collected by re gar the gate of PUT 2 3 through Zenadaio de 1 2. When the PUT 23 is turned on, the transistor 20 is also turned on through the resistor 22 and holds the PUT 23 on state. At this time the transistor 1 9 off to Runode, reuse Star 5 is in a set state capable of immediately firing past the zero-crossing point t _2.

AC power supply voltage V, but turning to the positive half cycle period through the zero-cross point t _2, rhinoceros squirrel evening 5 is turned on Fukutai, Do With the phase delay due to the inductance component of the choke coil 2 et current Is increasing. This current is the preheating current I, for the discharge lamp electrodes 3a and 3b. This preheating current I ”can be detected as the terminal voltage e 1 of the resistor 16, and at a time t ₃ when the current I 1 exceeds the set value I 0, the transistor 17 turns on and the transistor 2 passes through the resistor 22. Keep turning on 0. Note that the cathode terminal K of the PUT 23 is reversely biased to a higher potential than the anode terminal A connected to the common line Q, that is, a positive potential, so that the PUT 23 is reset. Then, it enters the standby state for the next non-discharge detection. When the preheating current I, starts falling after a delay of the AC power supply voltage ν ₁ , and falls below the set value I 0 at time t 4, the transistor 17 is turned off, and the current flowing through the resistor 22 of the 0 R circuit is turned off. Then, the transistor 20 is turned off, the transistor 19 is turned on in response, the gate potential of the thyristor 5 is pulled into the negative power source R, and the thyristor 5 is turned off. As a result, a kick pulse of a very low voltage V _K is generated between P and Q.

As long as the filaments 3a and 3b of the discharge lamp 3 are not sufficiently preheated, the discharge does not start even if a kick pulse is generated, the non-discharge state is detected, the preheat current is supplied, and the kick pulse is not generated. The process repeats. In that case, the supply duty of the preheating current I, is as shown in Fig. 3. This conduction phase angle 0 must be

7Γ.

After the filaments 3a and 3b of the discharge lamp 3 are sufficiently preheated, the discharge lamp 3 is discharged due to the occurrence of kick bals. In this case, the voltage between P and Q does not reach the non-discharge detection level ed even during the negative half cycle period. As a result, the PUT 23 does not turn on, the transistor 20 keeps off, and the transistor 19 keeps on, so that the AC power supply 1 shifts from the negative half cycle to the positive half cycle. Also, the thyristor 5 does not fire, so that no kick pulse is generated and the discharge state is stably maintained.

FIG. 4 shows a circuit diagram of another embodiment of the present invention.

The filament preheating circuit composed of a series circuit of the thyristor 5 and the resistor 16 and the control resistor 15 is the same as in the above-described embodiment.

A series circuit of a diode 26 and a resistor 24, which flow a current from the negative power source R to the control terminal P, and a zener voltage of the zener voltage defining the negative power supply voltage. A capacitor charged through the diode 25 and the diode 26. The negative DC power supply circuit composed of 27 is the same as the above-described embodiment. Is the same.

The non-discharge detection circuit composed of the two voltage dividing resistors 6 and 8 and the Zener diode 12 is the same as in the above-described embodiment.

Instead of the PUT 23 in the above embodiment, a capacitor 31 is used as a storage element. Transistor 30 is connected between the brass side terminal of capacitor 31 and common line Q to form a capacitor charging circuit, and base B of transistor 30 is connected to cathode K of Zener diode 12. When the voltage between P and Q exceeds the non-discharge detection voltage ed during the negative half cycle, the capacitor 31 is charged and memorized. The transistor 35 connected in parallel with the capacitor 31 forms a discharge circuit, and when the transistor 35 is turned on, the memory is reset. The base B of the transistor 35 is connected to the collector C of the preheating current detecting transistor 17 via the resistor 33.

The other end of the resistor 3 2, one end of which is connected to the brass side terminal of the capacitor 3 1, and the other end of the resistor 2 2, one end of which is connected to the collector C of the transistor 17 for preheating current detection, are connected to the other end. The circuit in which the resistor 34 is connected to the common connection point and the base of the NPN transistor 20 is connected substantially forms an OR circuit.

The fact that the inverting NPN transistor 19 is connected to the collector C of the transistor 20 and that the transistor 19 forms the control circuit of the thyristor 5 is as described above. This is the same as the embodiment.

The most important technical point of this embodiment is that when it becomes difficult to sustain the discharge at the end of the life of the discharge lamp 3 or when it becomes difficult to start the discharge, the ballast 2 by the preheating current to be continued is used. Temperature to reduce the heat generation of the That is, it is provided with ascending restraining means.

The temperature rise suppression means includes a positive temperature coefficient thermistor (for example, a product name Posister) 36 connected between the common line Q and the resistor 21, and a transistor for detecting a sudden increase in the resistance value of the positive temperature coefficient thermistor 36. A circuit means for connecting the transistor 37 to the emitter of the transistor 30 for charging the capacitor 31 to the base of the transistor 30 to forcibly turn off the transistor 30; and It is composed of a heat conduction device 38 that thermally transfers the heat generated by the preheating current detection resistor 16 to the positive temperature coefficient thermistor 36.

PTC Sir miss evening 3 6, for example urchin by showing a temperature characteristic diagram in FIG. 5, a desired temperature, for example, more than 6 5 'C, rapidly increases the resistance value from 1 0 ² Omega to 1 0 ^beta Omega This is a heat-sensitive resistance element. The heat conduction device 38 can be implemented by a thermal conductor that connects the resistor 16 and the PTC thermistor 36, or a positional relationship in which the PTC thermistor 36 is placed on the resistor 16.

Next, the operation of the embodiment shown in FIG. 4 will be described with reference to the time chart of FIG. The same parts as those in the operation description of the embodiment shown in FIG. 1 are represented by the same symbols and numbers, and the description thereof is omitted.

Tiger Njisuta 3 0, the potential of the control terminal Ρ in the negative half-cycle period relative to the potential of Komonrai down Q, to charge the capacitor 3 1 turned between on greater than the non-discharge detection voltage e _d. The base current of the transistor 20 is caused to flow through the resistor 32 by the charging voltage of the capacitor 31, and the transistor 20 is turned on and the transistor 19 is cut off at time t 1.

Preheating current I positive rhino squirrel evening 5 from time t ₂ by a half cycle and Tano down, start to flow, the set value I. From time t 3, transistor 17 turns on.

When transistor 17 is turned on, the capacitor The discharge transistor 35 of 31 is turned on by the base current by the resistor 33 to discharge the charge voltage of the capacitor 31, and the transistor 20 is kept on by the base current by the resistor 22.

That is, after detecting that the terminal pressure of the capacitor 31 is in a non-discharge state at time t, the preheating current becomes I in a positive half cycle. Are held until the time t ₃ in excess of.

The preheating current I, is the set value I. Follows transistor evening 1 7 at time t ₄ when made is turned off and the transistor 2 0 off by Tiger Njisu evening 1 9 is turned on, rhinoceros squirrel evening 5 generates a kick voltage V _k with data N'ofu.

If the discharge lamp 3 deteriorates and the kick pulse V _K continues to be emitted even if it is continuously generated, the calorific value of the ballast 2 due to the preheating current becomes excessive. In such a state, the temperature of the resistor 16 also rises. Therefore, the temperature of the positive temperature characteristic thermistor 36 rises through the heat conduction device 38, so that the resistance value sharply increases and the terminal voltage sharply increases. This causes the transistor 37 to turn on, forcing the charging transistor 30 to be kept off. As a result, the capacitor 31 is charged! : No current is supplied, the thyristor control transistor 19 is kept on, and the thyristor 5 is not fired, so that the filament current of the discharge lamp 3 is not discharged. When the temperature of the positive temperature coefficient thermistor 36 decreases due to the stop of the preheating current, and the transistor 37 returns to off, the lighting device starts to operate again.

FIG. 8 shows a time chart of the temperature of each part and the voltage between the two terminals P and Q when the discharge becomes difficult due to the failure of the discharge lamp. , Oite, T in FIG outside air temperature, T _{1 beta} temperature of the resistor 1 6, T _{3 e} is a positive characteristic thermistor evening 3 6 temperature, T, represents a predetermined control temperature. After power-on, involved in the lighting drive for generating a continuous gun illustrating a kit Kuba pulse V _K while Kyo耠the Huy lame emissions collected by preheating ¾ flow takes place If the discharge-disable state persists, the temperature of the resistor 16 first rises. The temperature of the positive characteristic thermistor 36 also rises slightly later. Eventually, Ding ₃₆ reaches the Seioroshi temperature Ding 5, transistor 3 7 preheating generation and Firame down bets kit Kuparusu stops by Tano down. During the idle period, the temperature Τ1β of the resistor 16 decreases, and the temperature T _{se of the} positive temperature coefficient thermistor _{36 also} starts to decrease with a delay. Thereafter, when _{3} returns to the control temperature Ts or less again, the transistor ₃₇ returns to off, and the first lighting drive is performed again.

Figure 7 shows the discharge start time from when the power is turned on until the discharge lamp turns on, using the commercial AC power supply voltage as a variable. In the figure, the solid line shows the measured values of the characteristics of the embodiment of the present invention shown in FIG. 4 and the dotted line shows the characteristics of the conventional example. In this test, the frequency of the commercial AC power source was 60 Hz, the choke coil 2, the discharge lamp 3, and the capacitor 4 were the same, and the room temperature and the lamp temperature immediately before the test were 25.9. Performed under the same conditions. According to the test results, the product of the present invention illuminates in 0.36 seconds at Vl-IOOV (RMS), which is 46% compared to 0.77 seconds of the conventional product. -At 90 V, the product lights up in 0.59 seconds, which is 34% compared to 1.74 seconds of the conventional product. The product lit in 0.8 seconds, whereas the conventional product could not be lit.

[Industrial applicability]

According to the present invention, since the two-terminal network is connected to both electrodes of the discharge lamp, it can be implemented by replacing the conventional glow lamp, and this two-terminal network is integrated into an integrated circuit (IC). By making it the same shape and size as the socket of the glow lamp, it becomes possible to replace the existing glow lamp for fluorescent lamp lighting. In this case, as is clear from the embodiment of the present invention, there is no place requiring adjustment after circuit assembly, so that productivity is high. In addition, according to the present invention, since there is no contact in the two-terminal network, there is a semi-permanent life, and the replacement work of the conventional glow lamp becomes unnecessary, and the deterioration of the glow lamp reduces the deterioration of the discharge lamp. Without delay, the life of the lamp is extended.

In addition, it operates stably even when the AC power supply drops, and operates more stably even in cold regions and low-temperature environments.

Claims

The scope of the claims

1. An AC power supply (1), a choke coil (2) as a ballast, and a discharge lamp (3) with a filament are connected in series, and a kick pulse is applied between both poles of the discharge lamp (3). A discharge lamp lighting device to which a generating capacitor (4) and a two-terminal network (terminals P and Q) are connected. When turned on, the preheating current is supplied to the above-mentioned filament. A unidirectional switching element (5) that generates a kick pulse between both electrodes of the discharge lamp, and one terminal (Q) of the two terminals (P> Q) has a negative potential with respect to the other terminal (P) It is determined that the capacitor (27) which is charged during the negative half cycle and becomes a negative DC power supply and that the voltage between the two terminals (P, Q) during the negative half cycle is greater than a predetermined value. A non-discharge detection circuit for detecting a non-discharge state of the discharge lamp; When the detection circuit detects a non-discharge state, the unidirectional switching element (5) is turned on at the beginning of the next positive half cycle to supply a preheating current to the filament and to detect the non-discharge state. A discharge lamp lighting device characterized by having switching element control means for holding an off state of the unidirectional switching element (5) when a circuit detects a discharge state.

2. In the invention described in claim 1, the switching element control means includes a storage means for storing that non-discharge has been detected by the non-discharge detection circuit, and the filament. The preheating current detection circuit that detects that the preheating current exceeds the predetermined set value (I.), and the preheating current detection circuit detects that the preheating current (I,) of the filament is equal to the set value (I.). n) When the following conditions are reached, the unidirectional switching element (5) is cut off. A discharge lamp lighting device comprising a switching element power-off means.

3. In the invention described in claim 1, a current measuring resistor (16) is connected in series with the unidirectional switching element (5), and is connected in parallel with the resistor (16). The preheat current detection is conducted by connecting the emitter-base circuit of the transistor (17) and connecting the collector circuit of the transistor (17) to the negative pole (R) of the capacitor (27) serving as the negative power supply. A discharge lamp lighting device comprising a circuit.

4. In the invention described in claim 2, the preheating current detection circuit includes a preheating current detection resistor (16) connected in series to the filament preheating circuit, and the preheating current detection circuit (1). A temperature sensor (36) thermally coupled with the switching element (37) for interrupting the non-discharge detection signal of the non-discharge detection circuit while the temperature of the temperature sensor exceeds a predetermined value. ). A discharge lighting device comprising: