JPS596640Y2 - Series discharge lamp lighting device - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a series discharge lamp lighting device.

When a plurality of discharge lamps are connected in series and lit, the voltage applied to both ends of the series circuit at startup must be equal to or higher than the sum of the discharge starting voltages of each discharge lamp.

Therefore, the voltage is insufficient to start these discharge lamps using a commercial AC power source.

Therefore, a step-up transformer must be used, but its step-up ratio must naturally be large, making it large and expensive.

Especially in high-output lamps, the discharge starting voltage is high, so
Such shortcomings are noticeable.

This idea does not use a transformer with a large step-up ratio.
Its purpose is to start and light discharge lamps connected in series.

An embodiment of this invention will be described with reference to the drawings. 1 is a commercial AC power source, 2 is a voltage doubler full-wave rectifier, which is constituted by capacitors 3 and 4 and diodes 5 and 6, as is well known.

This rectifier receives the voltage of the commercial AC power supply 1 as an input and generates a DC voltage approximately 25 times as large as the maximum wave value of this voltage.

Although the illustrated structure is designed to double the voltage rectification, it may be tripled or more.

7 is an impedance element for current limiting, 8 and 9 are lamps connected in series, and 10 to 13 are lamps for periodically inverting and applying lamp voltage (or lamp current) to both ends of the series circuit of lamps 8 and 9. The semiconductor switch is, for example, a transistor, and transistors 10.11 are connected to both ends of one electrode 8A of the lamp 8, and transistors 12.13 are connected to both ends of one electrode 9B of the lamp 9. Transistor 11 is connected in series, and transistor 12, electrode 9B, and transistor 13 are also connected in series, and the DC output voltage of voltage doubler full-wave rectifier 2 is applied to both ends of both series circuits.

14 is a starting element, 15 is a capacitor for sequential lighting, 16
A transformer is used to heat the electrodes 8B and 9A of the lamps 8 and 9, and is excited by the commercial AC power supply 1.

Reference numeral 17 denotes a pulse generation circuit (for example, a multivibrator, a tension oscillation circuit, etc.) for turning on each of the transistors 10 to 13.

A pulse from the pulse generating circuit 17 turns on transistor 10.13 and turns off transistor 11.12, and then turns off transistor 10.13 and turns on transistor 11.12.

Subsequently, transistor 10.13 is turned on again, transistor 11.12 is turned off, and this process is repeated.

This repetition period is determined by the pulse generation period of the pulse generation circuit 17.

Now the electrodes 8B and 9A of the lamps 8 and 9 are connected by the transformer 16.
is heated and the activation element 14 is turned on.

Then, when transistor 10.13 is turned on, a direct current flows through transistor 10, starting element 14, electrode 9B, transistor 13, and then transistor 11.
．． 12 is turned on, a direct current flows through the transistor 12, the starting element 14, the electrode 8A, and the transistor 11, and in this process, the electrodes 8A and 9B are heated, and eventually all the electrodes are heated. become.

When each electrode is sufficiently heated in this manner, if the starting element 14 is turned off, then the transistors are turned on and off as described above, and the DC voltage from the voltage doubler full-wave rectifier 2 is adjusted to both lamps 8, It is periodically inverted and applied to the 9 series circuits.

At this time, the applied voltage must be set to the voltage necessary to turn on lamps 8 and 9 one after another (for example, when two lamps are connected in series, approximately 1.5 times the discharge starting voltage of one lamp). For example, each lamp will turn on in sequence.

In the illustrated embodiment, one electrode 8A, 9 of the lamp 8, 9
Each end of B is open, and a transistor 10 is connected to each open end.
Although the electrodes 8A and 13 are connected, instead of this, lamps 8 and 9 in which both ends of the electrodes 8A and 9B are short-circuited may be used.

In addition, when the DC output voltage of the voltage doubler full-wave rectifier 2 is insufficient for the voltage applied to each lamp 8, 9 to meet the discharge starting voltage, the voltage of the commercial AC power supply 1 is boosted using a transformer. It may also be applied to a voltage doubler full-wave rectifier.

In this case, even if a step-up transformer is used,
It is clear that the step-up ratio can be much smaller than the step-up ratio of a step-up transformer without using a voltage doubler full-wave rectifier.

As detailed above, according to this invention, it is not necessary to use a transformer with a large step-up ratio to light the lamps connected in series, so the lighting device can be constructed compactly, inexpensively, and without noise. Moreover, even if a voltage doubler full-wave rectifier is used, voltage is applied to the lamp alternately, so there is an effect that the life of the lamp is not adversely affected as in the case of direct current lighting.

[Brief explanation of the drawing]

The figure is a circuit diagram showing an embodiment of this invention. 1... Commercial AC power supply, 2... Voltage doubler full wave rectifier, 8, 9... Lamp, 10-13.
...Semiconductor switch (transistor), 17...
...Pulse generation circuit.

Claims (2)

[Scope of utility model registration request] (1) A series circuit of multiple lamps and a voltage doubler full wave rectifier in which the commercial AC power supply voltage is subjected to voltage doubler full wave rectification, and the DC output voltage is set to be higher than the voltage necessary to sequentially light each of the lamps. a semiconductor switch for periodically inverting and applying the DC output voltage to both ends of the series circuit of the lamp; and a pulse generating circuit for generating a pulse for turning on the semiconductor switch. Electric light lighting device. (2) The voltage doubler full-wave rectifier is a series discharge lamp lighting device according to claim 1, which is a utility model registered, and which performs voltage doubler full-wave rectifier on a voltage obtained by boosting a commercial AC power supply voltage using a step-up transformer.