CN1028708C

CN1028708C - Fluorescent lamp or illuminator driven by dc with periodically changed polarity

Info

Publication number: CN1028708C
Application number: CN91105175.9A
Authority: CN
Inventors: 杨泰和
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-07-25
Filing date: 1991-07-25
Publication date: 1995-05-31
Anticipated expiration: 2006-07-25
Also published as: CN2103230U; CN1068927A

Abstract

The present invention provides a fluorescent lamp or an illuminating device of which the alternating strip lamp capable of periodically changing is driven by DC polarity, which is used for providing a stable illuminating function. The present invention comprises a supply device of a DC power source for generating the DC power source to drive the fluorescent lamp, a polarity exchange switch composed of an electromechanical element or a solid-state element, a light fixture and a polarity signal setting device, wherein the polarity exchange switch alternately switches the polarity of the DC power source and the positive connection or the reverse connection of both sides of the strip lamp by the instruction of the polarity signal setting device; the polarity signal setting device is a random number generator and is capable of forming an inconstant high signal or a low signal to drive the polarity exchange switch and set the positive polarity and the negative polarity of both ends of the strip lamp.

Description

Fluorescent lamp or illuminator driven by dc with periodically changed polarity

But the present invention relates to a kind of dc lighting device of Variable Polarity.

Since the fluorescent lamp invention, because it is high efficiency cold light source, have the advantage of energy savings and widely application, two types fluorescent lamp is arranged on market at present approximately, one is the fluorescent lamp that drives fluorescent tube with AC power, one is the fluorescent lamp that drives with DC power supply, and the former has accounted for great majority, uses in family, factory and public place.This mode cheapness, though but its brightness with the AC power waveform pulsation changes the setting that the current limit by inductance device is arranged, but effect is not perfect to the greatest extent, and form merit because of low, heat waste, noise are arranged, though and dc fluorescent lamp has good illumination stability, its one-sided negative electrode loss needs with artificial conversion fluorescent tube direction, quite inconvenience.

But the invention provides a kind of Variable Polarity dc fluorescent lamp or lighting device so that the illumination functions of high stable to be provided, is the brightness cycle pulsation injury eyes that form of power supply and with the fixing shortcoming of the unidirectional consume of DC power supply formation tube cathode with the interchange to replace at present.

But fluorescent lamp or lighting device that period of change of the present invention and alternation fluorescent tube are driven by direct current polarity comprise:

DC power supply device;

Light fixture;

It is characterized in that, also comprise:

The polar signal setting device, high frequency exchange polar signal and the low frequency thereafter of exporting an appropriate time exchange polar signal; With

Polarity switch, by two npn power transistors with constitute a bridge circuit after two PNP power transistors are connected respectively mutually, wherein first power transistor is connected with the 3rd power transistor, second power transistor is with after the 4th power transistor is connected, the emitter of first power transistor and second power transistor is access to power supply negative terminal, the emitter of the 3rd power transistor and the 4th power transistor is access to power positive end, the light fixture load then is parallel between the collector series connection point of the collector series connection point of first power transistor and the 3rd power transistor and second power transistor and the 4th power transistor, the bias resistance and first current-limiting resistance are for supplying to control first pliotron, second current-limiting resistance is for controlling second pliotron, the 3rd current-limiting resistance is connected in series two resistance and is to intersect and controls third and fourth power tube with load, so that can making positive reversed polarity to load, whole bridge circuit send, this bridge circuit is added transistor and is controlled, and adds transistor and controlled by the output signal of preceding described polar signal setting device.

But Fig. 1 is period of change and alternation fluorescent tube is subjected to the fluorescent lamp of electric direct-current polarity driving or the calcspar of lighting device.

Fig. 2 exports into the dotted state schematic diagram for each square of Fig. 1.

Fig. 3 is Fig. 1, the detailed circuit embodiment of Fig. 2.

Describe the present invention in detail below in conjunction with accompanying drawing.

Fig. 1 is a calcspar of the present invention, and 101 is DC power supply device among Fig. 1; 102 is polarity switch; 103 is light fixture; 104 is the polar signal setting device.

Fig. 2 goes into schematic diagram for the relevant output of this polar signal setting device, when starting shown in Fig. 2 fluorescent tube to be subjected to electric frequency be 5KHZ, become per 180 seconds after the starting and once be subjected to electric polarity for becoming, above-mentioned starting frequency and be subjected to electricity back alternative frequency to be all application examples, and be controlled by polar signal setting device 104; Each one can suitably select the alternation after starting frequency and the starting to be subjected to the electricity cycle being applicable to different lamps, and suitably modifies it and be subjected to electrical waveform or make the alternation between frequency be attenuating gradually.

Figure 3 shows that one of circuit embodiments according to above-mentioned square principle, its main composition is as follows:

-DC power supply device: for by an ac input end as the decompression capacitor C301 series bridge rectification BR302 of current-limiting impedance, the dc output end of a bridge rectifier BR302 commutation capacitor C303 in parallel is to obtain the high voltage direct current of a low ripple, leading to polarity switch, and then input load light fixture group; And constitute the low pressure power supply controlling by a dropping resistor R301 and voltage stabilizing Zener diode ZD301, and by Zener diode ZD301 two ends provide control power supply to the utmost point sexual intercourse change switches set;

-polar signal configuration switch group: for being main body by a controllable timing IC301 NE555, to produce the square wave of controlling of variable cycle, the main element that when switching on and shutting down, produces as square wave through IC301 NE555, for driving optical coupler OC301, IC301 is except that the peripheral RC element of coupling, mat wherein the RC time constant of resistance R 312 and variable resistor VR311 and capacitor C 311 to select to start the frequency of high frequency, being parallel to capacitor C 311 two ends in the circuit is constituted with variable resistor VR312 by photo resistance CDS311 and adjustment, wherein photo resistance CDS311 and adjustment variable resistor VR312 constitute, wherein photo resistance CDS311 can avoid the external light interference to be coupled in the lamp luminescence element for being arranged at, the resistance of CDS311 descends when light fixture is activated then, because CDS311 shunts with the parallel connection of its VR312 that connects, make former R312, the time constant that VR311 and C311 constituted makes light fixture be the low frequency and continuous operation, make the output cycle rectangular wave of IC301 reduce to low frequency gradually, to control the sending electrode of polarity switch group to load by high frequency; And IC301 recovers holding state because of CDS311 recovers high impedance when shutdown; This polar signal configuration switch group also can be made of with software a microprocessor, controls signal according to formula output frequency conversion;

-polarity switch: for by two NPN power crystal Q301, Q302 and two PNP power transistor Q303, Q304 constitutes a bridge circuit after the series connection respectively mutually, wherein Q301 connects with Q303, Q302 is with after Q304 connects, the emitter of Q301 and Q302 is access to power supply negative terminal, the emitter of Q303 and Q304 is access to power positive end, the light fixture load then is parallel between the collector series connection point of the collector series connection point of Q301 and Q303 and Q302 and Q304, bias resistance R311 and current-limiting resistance R317 are for supplying to control Q301, current-limiting resistance R313 is for controlling Q302, R314 is a current-limiting resistance, resistance R 315 and R316 control Q303 and Q304 for being to intersect, so that whole bridge circuit send electricity for making positive reversed polarity to load, this bridge circuit adds controlling of transistor Q305 for accepting, and Q305 then accepts controlling of aforementioned polar signal switch, when Q305 was conducting and open circuit, aforementioned bridge circuit was controlled load submission change poles.

In the moment of sending into alternating current dc fluorescent lamp is sent into high frequency alternation DC power supply through above-mentioned design and then reduce alternating cycles to continue that fluorescent tube is subjected to the starting fluorescent tube, because the no brightness pulsation of direct current input, the eye of not hurting sb.'s feelings, and owing to have the free signal setting device, in using, long-term accumulated will make the fluorescent tube both sides for just equating for negative probability is rough, and one-sided aging to prevent fluorescent tube; But the device of variable frequency and power supply polarity also can be used as the globality lighting apparatus is done the power supply of Variable Polarity to constitute the illuminator of a variable polarity power, its light fixture group of powering is except pure DC power supply of mat or daylight light fixture group that high-frequency pulse current drove, also suitable other lighting apparatus such as incandescent lamp or mercury vapor lamp or the inflation discharge lamp that contains DC load, the light fixture load of the indefinite polarity power of other applicable direct currents of arc lamp.

Comprehensively above-mentioned, the present invention has disclosed a kind of dc fluorescent lamp or lighting device is subjected to electric polarity to continue to light the lamp device of fluorescent tube with the high frequency period exchange with the starting fluorescent tube and with the cycle exchange fluorescent tube than low frequency, make and eliminated with the light period scintillation of fluorescent lamp that AC power is driven at present, and eliminate the shortcoming of the cloudy loss of the one-sided electricity of traditional direct-flow fluorescent tube simultaneously, and make quality of lighting improve, eye health obtains to ensure, the intention novelty, function is definite, is please examined in accordance with the law and examines to praying.

Claims

But 1, a kind of dc lighting device of Variable Polarity comprises:

DC power supply device; With

Light fixture;

It is characterized in that, also comprise:

The polar signal setting device, high frequency exchange polar signal and the low frequency thereafter of exporting an appropriate time exchange polar signal; With

Polarity switch, by two npn power transistor (Q301, Q302) with two PNP power transistor (Q303, Q304) constitute a bridge circuit after the series connection mutually respectively, wherein first power transistor (Q301) is connected with the 3rd power transistor (Q303), second power transistor (Q302) is with after the 4th power transistor (Q304) is connected, first power transistor (Q301) is access to power supply negative terminal with the emitter of second power transistor (Q302), the 3rd power transistor (Q303) is access to power positive end with the emitter of the 4th power transistor (Q304), the light fixture load then is parallel between the collector series connection point of the collector series connection point of first power transistor (Q301) and the 3rd power transistor (Q303) and second power transistor (Q302) and the 4th power transistor (Q304), bias resistance (R311) and first current-limiting resistance (R317) are for supplying to control first pliotron (Q301), second current-limiting resistance (R313) is for controlling second pliotron (Q302), the 3rd current-limiting resistance (R314) is connected in series two resistance (R315 with load, R316) be intersection and control third and fourth power tube (Q303 and Q304), so that can making positive reversed polarity to load, whole bridge circuit send, this bridge circuit is added transistor (Q305) and is controlled, and adds transistor (Q305) and controlled by the output signal of preceding described polar signal setting device.
2, but the dc lighting device of Variable Polarity as claimed in claim 1, it is characterized in that, described polar signal setting device comprises a controllable timing integrated circuit (IC301), main element as the square wave generation, for driving optical coupler (OC301), timing integrated circuit (IC301) is except that the peripheral RC element of coupling, mat wherein the RC time constant of resistance (R312) and variable resistor (VR311) and electric capacity (C311) to select to start the frequency of high frequency, being parallel to electric capacity (C311) two ends in the circuit is constituted with variable resistor (VR312) by photo resistance (CDS311) and adjustment, wherein photo resistance (CDS311) can avoid external light to disturb the element that is coupled in lamp luminescence for being arranged at, the resistance that is activated then photo resistance (CD311) when light fixture descends, the parallel connection of adjusting with variable resistor (VR312) is shunted because photo resistance (CDS311) is connected with it, make former resistance (R312), the time constant that variable resistor (VR311) and electric capacity (C311) are constituted makes light fixture be the low frequency and continuous operation, make the output cycle rectangular wave of timing integrated circuit (IC301) reduce to low frequency gradually, to control the sending electrode of polarity switch group to load by high frequency; And timing integrated circuit (IC301) recovers holding state because of photo resistance (CDS311) recovers high impedance when shutdown.
3, but the dc lighting device of Variable Polarity as claimed in claim 1 is characterized in that, described polar signal setting device comprises a microprocessor, by program control output exchange polar signal.
But as the dc lighting device of claim 2 or 3 described Variable Polarity, it is characterized in that 4, described light fixture comprises fluorescent tube or other gas fluorescent tube, tube face, flow restricter, necessary auxiliary actuator and connects lead and lamp housing.
But 5, the dc lighting device of Variable Polarity as claimed in claim 4, it is characterized in that, in the described DC power supply device: the ac input end of a decompression capacitor as current-limiting impedance (C301) series bridge rectification circuit (BR302), the dc output end of bridge rectifier (BR302) commutation capacitor in parallel (C303) is to obtain the high voltage direct current of a low ripple, leading to polarity switch, and then input load light fixture group; And by a dropping resistor (R301) and voltage stabilizing Zener diode (ED301) formation low pressure power supply controlling, and provide control power supply to polarity signal sets device by Zener diode (ED301) two ends.