JPS62200692A - Discharge lamp burner - 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 1 Technical Field The present invention is particularly applicable to dimming lighting in a discharge lighting device for preheating a discharge lamp.

rW Viewing Technology 1 A new dimming method is disclosed in VPN No. 113720/1989, which was previously filed by the present applicant.

A specific circuit diagram of this conventional discharge lighting device is shown in FIG.

This circuit is a half-bridge inverter circuit,
Direct tlt, power supply E is input, capacitors C,, C2,
Diodes D, ,D and main transistors Q, ,Q2
and a chiller coil L,1, as a load.
The discharge lamps LA are connected in series, and a capacitor c is connected in parallel to the lamps LA to form a series resonant circuit. A field pack signal obtained by a drive transformer T is applied to the bases of the main transistors Q, Q2 as feedback input layers. Further, between the pace emitters of the main transistors Q, . Q, are connected a, and their control is based on the lamp current II2. (a)) This is done by applying the output of the lance T2 to each base via the dimming switches S W + and S W 2. The dimming switches SW, SW2 are for switching between full lighting and dimmed lighting, and when turned on, the lighting is dimmed, and when turned off, the lighting is all lit.

In the above configuration, when the switches sw, , sw2 are off, that is, when the lights are all lit, the circuit maintains the lighting state at a certain frequency, as shown in Fig. m4 (a). In the figure, l01tIO2 is the collector current of each main transistor Q, , Q2, ■Old*I r12 is each diode o,
, l') is the current flowing through 2. Here switch s
When w, , S W 2 is turned on to enter the dimming state, during the on-period of the main transistor Q, a diode D is generated from the secondary 8 line n22 of the current transformer 'l'2.

A current is supplied to the sub-transistor Q through the sub-transistor Q, and the sub-transistor Q is turned on. Is this the base of the main transistor Q, which has been flowing until now? [K is cut, and at the same time, the charge stored in the floating capacitance between the base and emitter of the main transistor Q1 flows to the sub-transistor Q3, so the main transistor Q is rapidly turned off. Similarly, during the on-period of the other main transistor Q2, the sub-transistor Q is turned on, causing the main transistor Q2 to rapidly turn on. As a result, Figure 4(b)
As shown in Figure 4, the oscillation frequency of the inverter circuit is
The impedance of the inductive load becomes higher than in the case of full and wide lights in a), and dimming is performed by increasing the impedance of the inductive load. Figure 4 (
C) shows the state at this time in more detail digitally, and (a) in Fig. 4(e) shows the switches sw, s
w indicates the off state, that is, the on/off state of the main transistor Q in the fully lit state, and (b) shows the on/off state of the main transistor Q
w, , m) shows the on/off state of Lannostar Q3 at the moment when SWz is turned on. When the sub-transistor Q3 turns on, the main transistor Q turns off with a delay of m1 at τ. Therefore, the on-off period of the main transistors Q, ,Q becomes shorter as shown in (c), but at this time, the on-signal of the sub-transistors Q, ,Q is obtained from the lamp current, so the sub-transistors The on/off cycle of QUTQ4 is also synchronized with the on/off cycle of the main transistors Q11 and Q2, as shown in (c).Therefore, in the dimming state, the oscillation frequency changes as shown in (l) of the same figure. Note that the above-mentioned interval τ means the streak time until the main transistors Q, , Q, are turned off and the darkness of opening when falling.

Furthermore, it will be explained why the sub-transistor Q turns on with a delay when the main transistor Q1 is on, and why the sub-transistor Q4 turns on with a delay when the main transistor Q2 is on. In other words, there are two main transistors Q2), and in the on state, the main transistor Q2)
The base signal of No. 2 is the primary winding M n + of the drive transformer T.
This is obtained by a current flowing into the + terminal, and the switching of the main transistor Q2 is determined by the sign of this current. At this time, a signal for turning on the sub-transistor Q is obtained from S M n 2- of the current transformer T2. In this circuit, the winding method of the current transformer T2 is determined so that when the main transistor Q2 is turned on, the sub-transistor Q is also turned on, as described in the first part above. At this time, considering the phase of the current of the drive transformer '1 and the current transformer T2, the main transistor Q--he + '/
its M l^iT-419ill 1+Tu
Satoru 'M name r' - Capacitor C2 → Lamp LA and capacitor C3 → Chiyoke foil L1 → Drive transformer T,
primary winding nll → main transistor Q2 and capacitor C
2 discharge loop (capacitor C2→lamp LA and capacitor C5→chiyoke coil L1→main transistor Q,
) current is present. Here, the current flowing to the lamp LA and the current flowing to the capacitor C3 flow through the primary winding n of the drive transformer T. Therefore, the current flowing through the primary winding +111 of the drive transformer T1 is larger than the one large winding #i n 2 of the current transformer T2, which takes the lamp current.
The phase will advance compared to 1.

Therefore, after the main transistor Q2 turns on, a signal that turns on the sub-transistor Q enters with a delay, t
The result is a signal as shown in (c) of the Jch diagram (e).

Next, as another conventional example, there is a circuit as shown in FIG. 5 as an example of a new dimming method disclosed in Japanese Patent Application No. 113716/1980. DC power supply E is input, diode D,, l)
2 and main transistors Q, , Q2, and a starting circuit 4 consisting of a resistor R, a capacitor C, and a tri-element Z such as a diac, and a choke coil L as a load.
A series resonant inverter circuit is constructed by connecting the discharge lamps LA in series and connecting the capacitor C1 in parallel to the lamps LA. In addition, a driving transformer T1 is connected to the base of the main transistors Q, Q2.
The feedback signal obtained by is added. Furthermore, a sub-transistor Q4 is connected between the base and emitter of the main transistor Q2, and its on/off is controlled by the secondary Oi line n2□ of the current transformer T2 that detects the lamp current in the same way as shown in the conventional example above. Depends on the signal.

The switch SW2 is for dimming, and is closed during dimming. Furthermore, this switch SW
2 is closed, that is, during dimming, the sub-transistor Q,
The winding method of the current transformer T2 is determined so that the ON signal is obtained during the period when the main transistor Q2 is ON.

This operation is the same as that of the conventional example described above, so a description thereof will be omitted. Therefore, during dimming, the on period of main transistor Q2 is shorter than the on period of main transistor Q1. This is shown digitally as shown in Figure 6. Figure 6 (,) shows the on period of the main transistor Qm1Q2 when all lights are on with the dimmer switch SW2 off, Figure 6 (1)
) indicates the on period of the main transistors Q, , Q, during dimming when the dimming switch sw2 is on. As described above, in this circuit, by making the on-periods of the main transistors Q, Q2 unbalanced, the DC component is cut by the capacitor C1, and the lamp LA has no DC component.
A smaller current flows through the lamp LA when the main transistors Q, Q2 are on during the same period FM.

However, in the two conventional examples shown above, if the lamp is a fluorescent lamp that requires preheating,
ff1 point occurs during the following period.

Generally, in the case of fluorescent lamps etc. that require preheating, 2 lbf
Due to safety issues, it is best to apply high voltage to the lamp after preliminary preheating. As shown in FIGS. 3 and 5 of the conventional example, when a fluorescent lamp with preheating is used, the lamp LA in FIG.
The lamp LA is turned on by closing the switch SW connected in parallel to the lamp LA for a certain period of time after turning on the power, and then opening the switch SW3 similarly connected in parallel to the lamp LA in the MS5 diagram. Note that a circuit in which the switch SW3 is closed for a certain period of time after the power is turned on and then opened is omitted. However, referring to FIG. 5, after the power is turned on, the starting circuit 4 starts oscillating, and the preheating switch SW is closed for a certain period of time.

When the main transistor Q2 is on, the current flowing at this time is as follows: positive terminal of the DC power supply E → capacitor C1 → one filament r1 of the lamp LA → preheating switch SW → the other filament "2" of the lamp LA → current transformer T2
→ tick coil L, → drive transformer T, primary winding n
il → main trunk transistor Q2 → negative electrode path of DC power supply E, and when main transistor Q is on, capacitor C
In the direction of discharging the charged charge of I, capacitor C1
→ Primary winding nll of main trunk transformer QI-4 drive transformer T1 → Choke coil L, → Primary winding n21 of current transformer T2 → One filament r2 of lamp LA
→ Preheating switch SW, → Lamp LA filament r1
→Capacitor CILf) A current flows through the path.

Next, while the preheating switch SW is closed,
Since the resistance of filament f, , f is considered to be very small, almost no current flows through capacitor C1. Therefore, the drive transformer 'r.

The current flowing through the primary winding nll of T2 and the current flowing through the primary winding 121 of T2 are almost equal in phase and magnitude. As a result, dimmer switch SW2
In the dimming mode in which the main transistor Q2 is turned on during preheating, the base signal that turns on the main transistor Q2 and the base signal that turns on the sub-transistor Q match in phase. Therefore, when the main transistor Q2 tries to turn on, the sub-transistor Q also tends to turn on, causing the problem that oscillation eventually stops during preheating. Also,
Similarly, in the circuit of FIG. 3 shown in FIG. 3, when the main transistor Q is about to turn on, the sub transistor Q3
are also turned on, and during preheating, the dimmer switches sw,, sw,
If it is on, oscillation will stop.

[Objective of the Invention 1] The present invention has been provided in view of the above-mentioned points, and provides a discharge lamp that requires preheating, which can be sufficiently preheated in both full lighting and dimming without stopping oscillation. The present invention provides a discharge lamp lighting device for the purpose of.

[Disclosure of the Invention 1 (Structure) The present invention provides that the discharge lamp lighting device according to the present invention is a self-oscillating inverter circuit whose load is a series resonant circuit consisting of a Chitaak coil, a capacitor, and a discharge lamp, and the inverter circuit is configured. The g1 switching element is connected in parallel to the feedback input terminal of at least one main switching element, and a part of the output of the discharge lamp is fed back to the control terminal of the sub-switching element via a dimmer switch. In an inverter circuit that dims light by forcibly shortening the on-period with a sub-switching element, it is sufficient even in dimming mode by blocking feedback to the main IJ switching element regardless of whether it is fully lit or dimmed during preheating. This is a discharge lamp lighting VC device characterized by being able to be preheated and turned on.

(Example 1) Hereinafter, one example of the present invention will be described with reference to the drawings. In the conventional example, the switch for dimming (SW port SW2 in Fig. 3, 5W2 in Fig. 5) was determined to open or close only depending on whether all lighting was dimmed, but in the present invention, in addition to the above conditions, This means that the dimmer switch must be set so that the dimmer signal is not transmitted during preheating.

FIG. 1 shows an example in which the present invention is implemented in a series type inverter circuit. In FIG. 1, the inverter circuit corresponds to the conventional one shown in FIG. 5, and a transistor Q5 is used as the dimmer switch SW2 in FIG.
The contact r of the relay RF is used for this, and a control circuit 3 for preliminary preheating is configured as a circuit for controlling the relay Ry. These, transistor Q s +t relay Ys
The feedback input blocking means is constituted by the control circuit 3 for preliminary preheating of the contact r1 of the relay R, and the like. Transistor Q as a dimmer switch (SW2) is connected between the base and emitter of transistor Q, and a control circuit 3 that controls the contacts of relay Ry used as a preheating switch (SW3) connects DC power source E. A monostable oscillation circuit is constructed using a timer circuit ICI (for example, μPc1555C manufactured by NEC) using the voltage divided by resistors R7 and R2 as a power source.

The operation of this monostable oscillator circuit is as follows: If the voltage obtained by dividing the resistors R, , R2 is e, then the ■ pin of the timer circuit ICI (
When a voltage equal to or lower than 1/3)e is applied, the output terminal (■) pin becomes H level, and in this state, capacitor C6 starts to be charged via resistor R1, and the potential of this capacitor C becomes (2/3). ) When the battery is charged to e, the timer circuit I
The ■ pin of CI becomes "ON" state, and the ■ pin of the output terminal is inverted to L level. At this time, capacitor c6
The charges charged in the circuit are discharged through the ■ pin, and when a pulse of (1/3)e or less is applied to the ■ pin of the timer circuit ICI again, the same operation is repeated.

In this circuit, one of the outputs of the monostable oscillation circuit is connected to the base of the transistor Q6 that operates the relay Ry.
The other is transistor Q used as a dimmer switch.
, is connected to the base of.

In addition, the all-lighting/dimming mode switching circuit 2 connected to the control circuit 3 via the diode D7 sends a signal for all-lighting (
The dimmer switch described here is a switch that determines whether substantially all lighting is dimmed. Note that the contact point of relay Ry is used in a normal oven in this embodiment.

Next, the operation of this embodiment will be explained. First, when the power is turned on, the inverter circuit starts oscillating by the starting circuit 4, and at the same time, the timer circuit ICI starts to control the relay R.
Because the ■bin of is initially at L level, a signal enters, and the signal of the output terminal ■bin becomes H level. In response, the transistor Q6 turns on, and the excitation current flows through the relay Ry, closing the contact. Also, the H level of the full lighting/dimming mode switching circuit 2 is set by the output signal of the ■bin of the timer circuit ICI.
Regardless of the L level signal, the transistor Q is turned on. Therefore, the signals of the two large turns #in and □ of the current transformer T2 are not transmitted to the sub-transistor Q, and since they are always in an off state of 0 or more, after the power is turned on, all lighting/dimming mode switching circuits are not transmitted. Regardless of the switching signal from No. 2 for full lighting, full lighting, and dimming, preheating will continue for a certain period of time. After that, when the ■ pin of the output terminal of the timer circuit ICI goes to L level, transistor Q is turned off, relay R is not driven, contact r is restored and opened, and sub-transistor Q is turned on and off. It depends on the switching signal of the full lighting ul'l light of the full lighting/dimming mode switching circuit 2. In the case of full lighting, the transistor Q remains on and the sub transistor (
In the case of dimming lighting, the transistor Q is turned off and the current flowing through the primary winding 11□1 of the current transformer T2 is applied to the sub-transistor Q4, thereby turning on the main transistor Q2. The sub-transistor Q4 is turned on during the period, and the main transistor Q2 is forcibly turned on.
The light is dimmed by reducing the on period of the light.

As mentioned above, during the preheating period, all lighting and dimming mode switching circuit 2 outputs all lighting, 1! ! By always turning off the sub-transistor Q4 regardless of the light switching signal, the respective lighting states can be achieved after preheating is performed by turning on the power in both the full lighting mode and the dimming mode. In this embodiment, g11 trunk star Q,
As a method of determining whether or not to transmit a signal by the current transformer T, a transistor Q is used. The OR of all 5α lamp r7R optical mode switching signals from the likelihood mode switching circuit 2 is taken, but a separate switch may be provided in place of the transistor Q, and the switch may be used as a secondary switch during preheating. Any position may be used as long as the signal from the current transformer T2 is not transmitted to the transistor Q.

(Embodiment 2) FIG. 2 shows another embodiment, and this circuit solves the drawbacks of the conventional circuit shown in FIG. @Nando date G in figure 2
, , G 2, resistance Rs - Rs, capacitor Ct =
A monostable oscillation circuit 5 is configured with Cs and the like.

The switches sw, , sw, are connected to the transistor Qt and the relay tt by a signal from the full lighting/dimming mode switching circuit 2.
It is controlled to switch to all lights, g lights, and dimming mode via Y, and is set to be turned off in all lighting mode and turned on in dimming mode. Also, during preheating,
Preheating switch SW like relay contact, and switch SW
4 is set to be closed by relay Ry+.

The operation is the same as in the above embodiment, and during preheating, transistor Q is always turned on, relay RV1 is driven, switches sw, sw are closed, and MIN run transistors Q,
, Q, so that the signal from the current transformer T2 is not transmitted to the p-type transistors Q3 . Whether or not to transmit the signal from the current transformer T2 to Q is determined by the full lighting/dimming mode switching signal from the full lighting/dimming mode switching circuit 2. i1
! ! 1! ! In light, switches sw, , sw2 are on, and current transformer T is applied to sub-transistors Q, , Q.
2, each main transistor Q, ,Q,
The light is dimmed by forcibly shortening the period during which the light is on.

[Effects of the Invention] As described above, the present invention includes a sub-switching element connected in parallel to the feedback input terminal of at least one main switching element of a self-oscillation type inverter whose load is a resonant circuit consisting of a choke fill, a capacitor, and a discharge lamp. In a discharge lamp lighting device that adjusts light by feeding back part of the output to the control terminal a of the sub-switching element, it is possible to control whether the entire lighting is on or not. Regardless of whether the R light is turned on, the device is equipped with a feedback input blocking means that blocks feedback input to the sub-switching element during preheating. By not applying power to the switching element, even when the power is turned on in the dimming mode, it is possible to proceed from preheating to dimming lighting without any problem, without adding much circuitry.

[Brief explanation of drawings]

The first FA is a specific circuit diagram of an embodiment of the present invention, FIG. 2 is a specific circuit diagram of another conventional example same as above, FIG. 3 is a specific circuit diagram of a conventional example, and FIG. 4 is an explanatory diagram of the same operation. FIG. 5 is a specific circuit diagram of another conventional example, and FIG. 6 is an explanatory diagram of the same operation. Q, , Q2 are main transistors, Q , , Q are sub transistors, L is a choke coil, C, , C2 are capacitors, and LA is a discharge lamp. Agent Patent Attorney Ishi 1) Kai 7kS1 Diagram

Claims (1)

[Claims] (1) A sub-switching element is connected in parallel to the feedback input terminal of at least one main switching element of a self-oscillating inverter whose load is a resonant circuit consisting of a choke coil, a capacitor, and a discharge lamp, and the sub-switching element is connected in parallel to the control terminal of the sub-switching element. A discharge lamp lighting device that controls dimming by feeding back part of the output is provided with a feedback input blocking means for blocking feedback input to the sub-switching element during preheating, regardless of full lighting or dimmed lighting. Characteristic discharge lamp lighting device.