JPS596774A - Inverter device - Google Patents

Abstract

PURPOSE:To improve the efficiency of an inverter device by providing the tertiary coil, in which the collector current of a main transistor is flowed, in a base driving transformer to perform a positive feedback, thereby increasing the reverse base bias of the main transistor. CONSTITUTION:A discharge lamp L is fired by a separately-excited inverter 4 which has main transistors Tr1, Tr2 and an output transformer T0. Tertiary coils N3 are provided in addition to the primary and secondary coils N1, N2 in transformers PT1, PT2 for driving the base, the voltage N2 is added to the base of the Tr1 via a differentiator 13 which has a collector condenser C3 and a resistor R10, and the collector is connected to the tertiary coil N3, thereby performing the positive feedback. Accordingly, the output by the collector current is applied to the coil N2, thereby increasing the effect of the differentiator 13, and the collector current can be abruptly turned OFF, thereby improving the efficiency by simplifying the base drive circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applicable to a discharge lamp lighting device, etc. This invention relates to an inverter device.

The value r obtained by rectifying or rectifying and smoothing the alternating current g is
In a discharge lamp lighting device configured to light a discharge lamp using the output of the inverter circuit, an inverter circuit is driven by an inverter circuit using a current power supply. An excitation self-control type inverter device d is used. However, in recent years, separately-excited inverter devices are being used for the purpose of increasing the functionality of lighting equipment and increasing the efficiency of lighting circuits, as it is not possible to obtain a continuous dimming function if all separately-excited inverter devices are used. Due to the rapid development of semiconductor technology, the use of self-excited and self-limiting inverters is difficult to control the frequency, whereas separately excited inverters are difficult to control. This is relatively easy [T
A signal sending and receiving device using infrared rays with a focus on functionality (for example, an infrared link device for switching TV channels)
As a method to prevent interference with
Ijt'r is tested for use.

FIG. 1 shows an example of the configuration of a t-discharge and lamp lighting device using a conventional separately excited inverter device constructed based on the requirements as described in FIG. Specific circuit examples of the single drive circuit fi+ are shown in Figure 8 (λ) to (d).
Figures 1 and 2 are respectively diagrams for explaining the operation of the circuit. In the circuit shown in FIG. 1, a DC power supply (3) is formed from a commercial power supply Vs, a power switch S, a rectifier bridge (2), and a capacitor CO, and this DC type #i (:
(1K, therefore, the main transistor TrxνTr2, the output transistor 1'o, the main transistor 7,; the star "I" rx
An inverter circuit (4) consisting of a base drive circuit fll for driving +Tr2 operates. Output trasis°
On the secondary side of l"o, the lash L completes the I concubine via the child yoke coil C1'lX, and the filaments of the run z L are each connected to a preheating circuit (the preheating circuit is not shown in the figure). omission).

Here, the base drive circuit fil mentioned above has a circuit configuration as shown in FIG. .

That is @2r;! In the J circuit, (3) is a DC power supply, and the resistor RIIRII, capacitor Ct+C2, and inverter fi+161 and l- form an astable multivibrator circuit (7), and 18) in the figure is a flip-flop circuit. -y, [91tlol is a nacido 1 to 1 path, which divides the output of the above-mentioned astable multivibrator circuit (7), and connects it to the resistor R31 through the transistor 'rra
+'rra and hTrs +'rra t each alternately,
Adjust the time so that it turns on and off. In this way, the pulse transformers PT1 and PT2 are excited by the above-described alternate oscillation of the transistors Trs+Trs, and the resistors on the output side of these pulse transformers PTl P'r2 are
Between a and c terminals via R8 and diode D1+D2,
Between b and c terminals are shown in Figure 8 + all (b) 1
A stronger output appears, and the transistor Tr of the circuit shown in FIG.
This will drive ltTrz.

When the power switch S is turned on in path 101 in Figure 1, a DC power supply (3) is formed by the rectifier bridge (2) and CO'J, and at the same time, as shown in Figure 2, The main transistor Trt+'rrt is turned off alternately by the base drive circuit 0) having a circuit operation as described above, and therefore, a current in the opposite direction alternately flows through the primary winding of the output cadence 1゛O with the center tap. The secondary side of Quadrance RO [Start the Runzu L! Output for lighting is obtained. In addition, choke coil CB, Hausizu L
is a stable element. By the way, in an inverter lighting device that performs such an operation, its main transistor Tr
The collector current IC and collector voltage VC flowing through TrzK and TrzK have waveforms as shown in Figure 3 (C) and (Φ), respectively.As is clear from FIG. Since the current IC is a triangular wave and the current IC is a triangular wave, there is a risk that the loss of transistors and transistors at the time of switching will become large.
Since the winding of the output transformer TO is connected in series with t'rr2%, it becomes an inductive load, and compared to a resistive load, it is difficult to interrupt the collector current, and the collector current also rises faster. Therefore, there is a problem that transistor loss increases even more.

Therefore, it is necessary to speed up the turn-off of the main transistors Trt + Trz and reduce the turn-off loss (Poff). Let me explain an example that has been proposed in the past.First, as one method for this purpose, a method has been proposed in which the excess base current is eliminated and the transistor is used in a non-saturated state. With this method, the turn-off time of the transistor can be shortened and the switching loss can be reduced, but on the other hand, there is the problem that the loss when the transistor is turned on is increased.Next, as shown in Fig. 4. (1
A single drive method has also been proposed, such as the σ drive method shown in 1, in which the collector current is fed back to the base to prevent more base current than necessary from flowing.
The base dry → collector current is transformed by a transformer Cr to supply a base current T which is proportional to the collector current, and the turns ratio of the transformer Q' in the circuit shown in Fig. 4 is 2 n = N2. /Nl, then IB = 1c7
n IB, hpg) HP from the conditions of Ic.
E') may be set as n, where bpE is] Care must be taken to saturate the VC across the collector terminals even if the collector current is at its maximum. In this way, in the case of this Cr drive type, the base current can be passed critically over the entire collector current range, so the storage time [ii] can be shortened and the loss can be reduced. Is there a main transistor 1'?
rt's terminal e ta:/o"') 0) 1: MeK It, on terminal (11) 1it) vc 4th
The on pulse IBI as shown in the figure (01 (bl K)
In addition, it is necessary to externally apply an OFF pulse In2 as shown in Figure (a) K to the ON terminal QJ (1gl), and especially at turn-off, a large pulse IBg with a different pulse width from the ON pulse IBI is applied. It is necessary to instantaneously neutralize the signal applied to the base region during accumulation, and as mentioned above, it is necessary to externally input two types of pulses for the bird 15 with different pulse widths and amplitudes. There is a problem in that the circuit configuration of the control circuit that generates the trigger pulse becomes complicated.

Fig. 5 shows another conventional example in which the base inverse tS is strengthened, in which a reactor L is inserted between the base of the main transistor ``I''rt and the collector of the auxiliary transistor Tro. A part of the current is passed through the reactor L, and when the auxiliary transistor Tro is turned off, the energy released from the reactor L is used to power the main transistor Tr.
This is a T-device that aims to speed up the main transistor Trx by applying the full pick-up bias between the base of 1 and 1 and flowing a reverse current to the base. In the same figure, (II) shows the waveforms of the base voltage VBE, (bl indicates the base current in, and (c) shows the waveforms of the reactance 5m flow IL. However, in the conventional example shown in Fig. 6 (a), If so, an auxiliary transistor Tro having the same withstand voltage as the main transistor Tr1 is required, and there is a problem that the auxiliary transistor Tro must be used, which is expensive.
The turn-off speed of the reactor L is also a problem, and in order to obtain a sufficient base reverse bias, it is necessary to make the reactor L large. Figure 6 shows a general configuration example, which is configured to give a base signal for reverse bias to the base. In the base signal shown in FIG. 6, IBI is a forward bias ON signal, and Ing is a reverse bias OFF signal. In this case, the turn-off time tf
In order to shorten K, it is sufficient to increase the reverse bias signal IB2.
shows the relationship between IBI and IBI for the case of IBI = IB2.
=81B1, tf becomes H, IB2 ==51
In the case of 81, l/foK is shortened, and conversely, in the case of IBg of 0, [f becomes large and the desired effect can be obtained, but the reverse bias base current is In order to provide a large current, a large-capacity power supply is required, which has the problem of complicating the design of the base drive circuit and increasing the size of the device.

The present invention has been provided in view of the above points, and does not require the use of a large-capacity base drive circuit, and has a simple circuit configuration that reduces switching loss of the main transistor without increasing other losses. The overall purpose of the present invention is to provide an ishiverter device that can achieve high efficiency and reliability.

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 7 shows a circuit diagram of the main part of the present invention - an embodiment, and FIG. 8 is an explanatory diagram of its operation, in which the transformer PTK for base drive - secondary winding Nl, secondary winding N2, eighth winding A line N3 is provided to input a drive current 10 having bipolar parts as shown to the primary winding Nl, and an output from the secondary winding N2 is input to the base circuit of the main transistor Trx.
The 8th winding N3 [ is connected to the main transistor Tr according to the polarity shown in the figure.
A differential circuit 03) consisting of a decimal resistor C3 and a resistor 9 is inserted and connected to the base circuit of the main transistor Trx on the output side of the secondary winding N2. has been done. Thus, in this embodiment circuit of FIG. 7, the base drive transformer P'
The drive current io [proportional output t] as shown in FIG. It is supplied to the base of register Trt. If now, the 8th winding N3
If there is no base current iB of the main transistor Tr1, the waveform of the drive current i0 is differentiated by the capacitor C3 and the resistor R9, as shown in FIG.
The main transistor Tr1 is driven by this base current in, and a collector current IC as shown in FIG. 2C flows (assuming that the collector current has a rectangular waveform). However, this figure 7 'IETm
In the example circuit, the VC actually has an eighth winding N3 and the collector current iC' described above is passed through it, so the output from the secondary winding gNz K /d and the collector current c which is magnetically coupled with this is As a result, the actual base current 1nFi becomes as shown in the same figure (d), and the differential circuit [1
As a result, the differential effect due to 3+ increases, and the collector current ic of the main transistor 1r1 turns off more sharply as shown in el.In this way, the collector current feedback of the base drive transformer PTK A tertiary winding N3 is provided for the main transistor
By the joint effect of providing a differential circuit in the base circuit of x, the base reverse bias of the main transistor frx can be increased. It is possible to reduce the +M loss Pf at the time of turn-off of the main transistor Tr1 with a simple configuration (addition of parts) without making the main transistor Tr1 turn off. Note that when the collector current is a rectangular wave as in the above embodiment, the turn-on operation becomes faster, and the turn-on loss Pn
is multiplied by several times, but if the load-side circuit is inductive, the loss during turn-on is usually much smaller than that during turn-off, so it does not cause much trouble.

9-(a) to 0-xun show different variations of the above-mentioned embodiment in FIG. 7, and the embodiment in FIG. , the base current in of the main transistor Trl as shown in FIG. 8(d)
By changing the shape of the damage line uvc from the state of the broken line in Fig. 10,
The base current iB is adjusted. Next, the same sentence (DJ
A practical example of this is to connect a parallel 1C base current and a diode D1 with the opposite polarity to the capacitor C3, which has the effect of further increasing the reverse bias current in the base current iB waveform described above, and also increases the base circuit. By reducing the circuit impedance in the opposite direction of the main transistor T
It has a function of protecting the main transistor rr1 by lowering the reverse voltage between the base and emitter of r1. Furthermore, the same figure 0
9 is a resistor R1o and a diode D in parallel with the capacitor CNC.
1 is added, and it is constructed by combining (A) and - in the same figure, and the effects of each are as described in Figure (force and (0)). In each of the circuits shown in FIG. 7 and FIG. 9 (A) to 0.
Although 11 is shown as being composed of a capacitor C3 and a resistor R9, it goes without saying that a differentiating circuit may be constructed using, for example, an interface and a resistor.

Fig. 11 (A) ([jFi] This shows an example of the circuit when the circuit shown in Fig. 9 09 described above is actually applied to a discharge lamp lighting device, and corresponds to the conventional example shown in Figs. 1 and 2 described above. It is.

That is, this embodiment circuit is the same as the conventional example circuit of the second circuit by adding cosidancers C3 and C4, and adding 7 for collector current feedback to the base drive transformers PTt and PT2.
The 88th winding N3 is added, as shown in Figure 11 ((a)
The terminals a to g in the circuit are connected to the terminals 3 to g in the circuit shown in the same figure (0).Thus, in this example circuit, the operation is as described above. However, especially in the case of a push-pull type inverter system such as the one shown in FIG. will be further encouraged.

FIG. 12 is an explanatory diagram of the operation of the circuit shown in FIG.
In the circuit] Njinsa C3, C4 and 8th winding Ns
, N3 is not present, that is, in the case of the conventional @8 circuit, the base current int given is shown in the 12th M(a). Adding f, the base current in this case is
z is shown in fb) of the same figure, and in this case, the base current waveform has been improved by the differential effect described above in the direction of reducing switching loss, but it is still insufficient, and at that time, the collector of the main transistors ゛rr l, Trz current ic
x is the collector voltage v (J: t) As shown in the same figure (C) with respect to K, it lacks a little steepness at the time of cut-off, and the switching characteristic Pf at turn-off is not improved to that extent.Therefore, in the present invention, further, in the present invention, The 8th winding N3 for collector current feedback is connected to the base drive transformer PTl, P1'2
In addition, the above-mentioned decrease in the collector current ict at the time of interruption is applied as the output of the secondary winding N2 to the main transistor rr1.
A reverse bias is supplied to the base of Tr2, and the base current iBs at this time is the same [Figure (d)] [As shown, the reverse bias further increases i. Therefore, since the collector current ic2 of the main transistor I'rl at this time is abruptly cut off by VC as shown in Figure 1m(e), the collector current VCB2 also rises steeply and at turn-off. Switching loss Poff can be significantly reduced. In this way, if the present invention is applied to a circuit in which the current flowing through a switching element such as a spur-type inverter with an inductive load gradually increases and then falls at a certain point in the form of a triangular wave, the switching behavior at turn-off can be reduced. This has the effect of significantly reducing the amount of water. That is, four 82W annular fluorescent lamps were lit, and the lamp output sound 4 (lQmA was kept constant), and the lighting device used was the conventional one shown in Figure 1 @219.
In this case, the example shown in FIG. 11 is used.

As a result of measuring the input power when

FIG. 18 is a circuit diagram of a second configuration example of the present invention.

FIG. 14 explains the operation. That is, the 18th
In the circuit shown in the figure, a current transformer Cr is connected in parallel with the base resistor R13 of the output circuit of the conventional base drive transformer PT.
A series circuit of one winding of the diode D3 and the diode D3 is connected, and the diode D31d is oriented to prevent forward bias of the base of the main transistor Trx. Further, the other windings of the current transformer a are inserted at the point If where the collector current of the main transistor Trt flows, and each winding is wound in the direction shown. Thus, in FIG. 14, the base current iBl in the conventional circuit without the current transformer C-I' and the diode D3 is shown, so that the collector voltage icx of the main transistor rrl and the collector voltage V (The loss Pfr/i at turn-off is large as shown in (b) of the same figure.) In this case, the collector current is assumed to be a triangular waveform.Next, for the conventional circuit described above, When the circuit of the embodiment shown in FIG. 13 is constructed by adding a current transformer D' and a diode D3, the diode D3 is turned on when the collector current icy falls, and this is the main transistor. Since it is added to the base reverse bias of Trx, it is effective in turning off the main transistor Trl more quickly.The base current iB2 in this case is shown in Fig. 14(C).K, collector current, voltage icz, vcEz f
The same fit (d) VC is shown respectively.

Next, FIGS. 15(A) to 0(R) each show a modified example of the 18th baby circuit, and the circuit in FIG. This circuit has the effect of adding a transducer C5 in parallel with the resistor 1ζ13, and the base current waveform is differentiated by the resistor 1ζ13, thereby reducing the switching voltage.Additionally, the diode D3 in series with the base resistor R1
A parallel circuit of a capacitor C6 and a resistor Ri4 is provided in parallel with 3, and the base reverse bias current is differentiated.

Since the present invention is configured as described above and is a single device, it is possible to reduce the switching loss of the main transistor, especially the loss at the time of turn-off, by a simple circuit configuration. There is no need to provide a base drive circuit, and there is no need to increase other losses, and the effect is that high efficiency and reliability can be easily achieved.

[Brief explanation of the drawing]

The first direction is the circuit diagram of the conventional example, @21jl? :t 1i
The circuit diagram of the base drive circuit on jl, Fig. 8 is the explanation of the previous work on the same as above, Fig. 4 a) (Ol is the principle circuit diagram of the conventional D' drive system and its input waveform diagram, Fig. 5 a) 009 is a basic circuit diagram of another circuit example of the conventional base reverse bias reinforcement method, and FIG.
Input waveform diagram and relational characteristics between reverse bias base current and storage time (support), the 7th leap is a basic circuit example diagram of an embodiment of the present invention, Figure 8 is the operation explanation M of the same as above, Figure 9 f-1 '
) ~ 0 Most are diagrams of different modified circuit examples of the above-mentioned circuit in FIG. 7,
Figure 10 is an explanatory diagram of N)7 of the circuit in Figure 9 (A), and Figure 11.
Figure (b) is a circuit example diagram when one embodiment of the present invention is applied to a discharge lamp lighting device, @12- is an explanatory diagram of the operation of the circuit in Figure 11, and Figure 818 is a diagram of another embodiment of the present invention. Basic circuit example diagram,
The 141st chrysanthemum is an operational explanatory diagram of the circuit shown in Fig. 18, and Fig. 15 (A 1 to 0 are diagrams of different modified circuit examples of the circuit shown in Fig. 18. Line, CTI/i current transformer, 03) is a differentiating circuit. Representative Patent Attorney Ishi 1) Cover 7112 Figure 14 Figure 01

Claims (1)

[Claims] (1) A transformer for driving the base of the main transistor is provided, and a base forward bias current and base reverse bias are created by inputting a drive signal having both positive and negative polarity parts to the primary side of the transformer. An inverter device comprising: a drive current generating circuit configured to generate a current; and positive feedback means for positively feeding back the collector current of the main transistor to its base side. (2) An eighth winding for passing the collector current of the main transistor is provided in the base drive transformer to constitute the positive feedback means, and a differentiating circuit is inserted and connected to the secondary output circuit of the transformer. The inverter device according to claim 1, characterized in that: (3) A current-carrying element, such as a resistor or a diode, that conducts a current in a direction that gives reverse bias to at least the base is connected in parallel to the capacitor constituting the differentiating circuit. The inverter device according to item 2. (4) The inverter device according to claim 2 or Fi 8, wherein the load side circuit is configured so that the collector current of the main transistor gradually increases to form a triangular wave. . 15) Connect the secondary output circuit of the base drive transformer to the base of the main transistor 7 transistor via the base resistor, and provide a current transformer to which the collector current circuit VC primary side of the main transistor is inserted and connected; 2. The inverter device according to claim 1, wherein a series circuit of a secondary winding of the current transformer and a diode is connected in parallel to the base resistor. (6) Instead of the above base resistor, use a parallel circuit of a capacitor and a resistor or py-i! The inverter device according to claim 5, characterized in that the inverter device is connected to a rinser. (7) A parallel circuit of a capacitor and a resistor is connected to the connection point between the diode and the base resistor or a circuit element connected in place of the base resistor. 6. The input device according to item 6 or item 6. (8) The load-side circuit is configured such that the collector current of the main transistor becomes a triangular wave that gradually increases. The inverter installation described in ftQ