JPS58161297A - 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 a discharge lamp lighting device using a transistor inverter.

Conventional transistor inverter type discharge lamp lighting devices include those that use a relatively high-voltage DC power source as a power source, and those that use a commercial power source as a power source by rectifying the output without converting the voltage. In these lighting devices, the power source that energizes the transistor pace and the power source that energizes the collector are common, so there is a drawback that the shunt resistor that limits the total transistor pace current consumes a large amount of power. .

Figure 1 shows a conventional discharge lamp lighting device that directly rectifies the output of a commercial power source to drive a transistor inverter.
02, a constant current reactor 2', a transistor inverter 6' consisting of transistors 301, 302, a capacitor 606, a shunt resistor 604, 305, and an oscillation transformer 606, and 9 connected to the secondary side of the oscillation transformer. It is a discharge lamp. In such a discharge lamp lighting device, in order to flow a constant FA pace current through the transistors 301 and 302, it is necessary to flow a current determined by the current amplification factor hfe of the transistors 301 and 302 through the resistors 604 and 305, and the power supply voltage increases. If the resistance is high, there is a drawback that the power loss in these resistors becomes large. For example, when lighting a fluorescent lamp of 40W or more, this power loss reaches several watts, and when the commercial power supply is 200V, this power loss reaches more than 10 watts, resulting in a lot of unnecessary power consumption. This was extremely uneconomical.

An object of the present invention is to provide a discharge lamp lighting device that eliminates the above-mentioned drawbacks.

In the present invention, a constant current reactor having a primary and a secondary winding is used, the collector current of the transistor constituting the transistor inverter is supplied by the primary winding of the reactor, and the base current is supplied to the secondary winding of the reactor. It is configured to be supplied by winding. With this configuration, the collector circuit and base circuit of the transistors constituting the inverter can be separated, and power loss due to the current limiting resistor of the pace circuit can be reduced.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The discharge lamp lighting device of the present invention will be explained in detail below with reference to the illustrated embodiments.

FIG. 2 shows an embodiment of the present invention, in which a constant current reactor 2 has a primary winding 20 connected to an iron core 200.
It is constructed in the form of an insulated transformer in which primary and secondary windings 202 are wound. The first transistor constituting the transistor inverter 6
The emitters of the second transistors 301 and 602 are commonly connected, and a capacitor 606 and a primary winding 306a of an oscillation transformer 6060 are connected in parallel between the collectors of these transistors. A feedback winding 606c provided in a transformer 606 is connected between the bases of the transistors 601 and 502.
One ends of resistors 604 and 305, each having a relatively low resistance value, are connected to the 0 base and the pace of the transistor 302, respectively.

Further, one end of a capacitor 607 is connected to the emitter common connection point C of the transistors 301 and 302, and the other end of the capacitor 607 is commonly connected to the other ends of the resistors 604 and 605-5. The positive DC output terminal A of the rectifier 102 of the power supply 1 is connected to the primary winding 306 of the transformer 306.
A resistor 308 having a high resistance value is connected in parallel between this intermediate tap and a common connection point E between the resistors 304 and 305 and the capacitor 307.

The negative DC output terminal Bil''1 of the rectifier 102 of the power supply 1.
Transistor 3 runs through the primary winding 201 of reactor 2
01. +02 emitter common connection point C. One end of the secondary winding 202 of the reactor 2 is connected to the emitter common connection point C of the transistors 301 and 502, and the other end is connected to the common connection point E of the capacitor 307 and the resistors 604, 305, and 308 through a rectifier 609. has been done.

The discharge lamp 8 is connected to both ends of the secondary winding 606b of the transformer 606, and taps t++t2 are provided near both ends of the secondary winding 606b.
06b is applied to the filament of the discharge lamp 9.

6- In the example shown in Fig. 2, an isolation transformer type having separate primary and secondary windings is used as the constant current reactor, but one end of the primary winding 201 and one end of the secondary winding line 20
Since the two ends are commonly connected, it is also possible to use a single-turn transformer-type glue axle with a tap drawn out from a single winding, as shown in FIG. If a single-turn transformer-type glue axle is used, the insulator between the primary and secondary can be omitted, resulting in miniaturization.

In the embodiment described above, when the output of the commercial power supply 101 is applied to the full-wave rectifier 102, the DC output of the rectifier 102 is applied to the transistor inverter 6 through the entire reactor 2. At this time, a resistor 608 with a sufficiently large resistance value and a resistor 604.305 with a relatively low resistance value are connected to the rectifier 102.
A base current of several mA flows through the transistors 501 and 302 through ', and a collector current flows through the transistors 301 and 302. When collector current flows through the transistors 301 and 302, the constant current reactor 20 primary winding 201
A current flows through the secondary winding 202, and a voltage is induced in the secondary winding 202. When a voltage is induced in the secondary winding 202, a current of several mA is supplied from the power supply 1 side through the resistor 308 and the secondary winding 202
The combined current with the current flowing through the rectifier 309 from the side flows through the resistor 304 and the transistor 601.3 through the resistor 304 and the current flowing through the rectifier 309.
Transistor 30 to flow to the base of 02
The base current of 1°302 increases and its collector current increases. In this way, the transistor inverter 6 is kept in an oscillation state, and finally the secondary winding 2
It stabilizes to a stable state determined by the number of turns of 020 and the resistance values of resistors 304 and 305. As described above, according to the device of the present invention, the power loss due to the current of about several mA flowing through the high resistor 608, which is necessary for starting the inverter, and the minute power loss generated in the low resistor 304, 305, rectifier 309, and reactor 2 Transistor 601゜60 with only power loss
2 bases can be energized, reducing unnecessary power consumption.

In the above embodiment, the secondary winding 202 of the reactor
Although the output of the rectifier 309 is directly rectified and supplied to the base circuits of the transistors 301 and 302, a resistor 610 may be connected in series with the rectifier 309 as shown in FIG. By inserting the resistor 310 in this way, the oscillation output (supplied to the discharge lamp) due to variations in the constants of components such as the transistors 301 and 302, the capacitor 606, and the oscillation transformer 306 can be reduced by simply adjusting the resistance value of this single resistor. It is possible to easily correct variations in the output (output).

Furthermore, as shown in FIG. 5, by inserting a starting delay circuit 311 between the rectifier 609 and the base circuits of the transistors 301 and 602 to delay starting, the discharge lamp 9 can be prevented from turning black at an early stage. It can also be prevented. The start-up delay circuit shown in FIG. 5 includes a thyristor Th whose anode is connected to a rectifier 6090 cand and a cand connected to a common connection point E of resistors 304 and 305, and between the anode gate and gate cand of this thyristor. From the resistor R1r & connected in parallel, the capacitor C connected in parallel to the resistor R2, and the series circuit of the resistor R3 and capacitor C connected in parallel between the anode gate of the thyristor 9-Th. It has become. In this delay circuit, the voltage induced in the secondary winding 202 first charges the capacitor CI to the polarity shown in the figure through the resistor Rye, and when the voltage across the capacitor C1 reaches a predetermined value, a gate current is applied to the thyristor Th. The current flows and this thyristor Th becomes conductive. Therefore, the flow of base current to the transistors 301 and 302 is delayed due to the induced voltage in the secondary winding 202 until charging of the capacitor CI is completed.

Incidentally, since the starting delay circuit shown in FIG. 5 is inserted into a low voltage circuit, it can be constructed using inexpensive components.

Since the above constant current reactor 2 has 4 terminals or 3 terminals, it can be stably supported even if it is directly attached to a printed circuit board, etc., and it can be stably supported when a conventional 2-terminal constant current reactor is stably supported on a board, etc. You can omit the holder etc. required for By omitting the holder in this way, the space for mounting the reactor can be saved = 10 =, so the device can be made more compact.

As described above, according to the present invention, the collector circuit and base circuit of the transistors constituting the inverter are separated, and
By reducing the loss in the current limiting resistor of the base circuit,
There is an advantage that power loss of the inverter type discharge lamp lighting device can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a connection diagram showing a conventional example, Fig. 2 is a connection diagram showing an embodiment of the present invention, Fig. 6 is an equivalent circuit diagram of a modified example of the constant current reactor used in the present invention, and Fig. 4' ( and Fig. 5 are connection diagrams showing different modifications of the secondary side circuit of the reactor used in the present invention. 1... Power supply, 2... Constant current reactor, 201...
・Primary winding, 202... Secondary winding, 3... Transistor inverter, 601, 602... Transistor,
606...Oscillation transformer, 9...Discharge lamp. = 11-

Claims (6)

[Claims] (1) A constant current reactor having primary and secondary windings is connected between a power source and a transistor inverter, and the collector current of the transistor constituting the transistor inverter is changed by the output of the primary winding, and the base current is A discharge lamp lighting device characterized in that the constant current reactor and the transistor inverter are connected to each other so that the constant current reactor and the transistor inverter are supplied with each other by the output of the secondary winding. (2) The discharge lamp lighting device according to claim 1, wherein the constant current reactor is comprised of a single-turn transformer type glue handle in which a single winding is provided with a tap. (3) The discharge lamp lighting device according to claim 1, wherein the constant current reactor is an isolation transformer type reactor having separate primary and secondary windings. (4) The transistor inverter includes first and second transistors whose emitters are commonly connected, and an oscillation transformer with a primary coil connected between the collectors of both transistors, and the primary winding of the constant current reactor is The secondary winding of the constant current reactor is connected between one end of the power supply and the common emitter connection point of the transistors, one end of the secondary winding of the constant current reactor is connected to the common emitter connection point of both transistors, and the other end is connected to the bases of both transistors. A discharge lamp lighting device according to any one of claims 1 to 3, which is coupled through. (5) Claims 1 to 4, wherein the transistor inverter includes a rectifier between the secondary winding of the constant current reactor and the base of the transistor.
The discharge lamp lighting device according to any one of paragraphs. (6) The discharge lamp lighting device O according to claim 5, wherein the transistor inverter includes a delay circuit between the rectifier and the base of the transistor and having a switch means for delaying conduction at the time of starting.