CN202759619U

CN202759619U - Negative resistance compensating circuit

Info

Publication number: CN202759619U
Application number: CN 201120551927
Authority: CN
Inventors: 何曙光
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-12-23
Filing date: 2011-12-23
Publication date: 2013-02-27
Anticipated expiration: 2021-12-23

Abstract

The utility model provides a negative resistance compensating circuit, which belongs to the technical field of lamp power sources and is used for negative resistance compensation during dimming of an LED lamp. According to the negative resistance compensating circuit, two alternating-current input ends of a rectifier bridge VC1 are two terminals of a negative resistance module, and an electrolytic capacitor C1 is connected to positive and negative ends, where a direct-current voltage is outputted, of the rectifier bridge VC1. A negative resistance circuit is made into a small module, is connected in parallel with an input end of a lamp and then is connected in series with a thyristor dimmer so as to be connected to the alternating-current commercial power, which means that a 220V alternating-current commercial power loop has a dummy load and still a small current flows through the dummy load when an effective value of the alternating-current output is lower than a threshold value of a working voltage of the lamp, thereby achieving the 'compensating' function, guaranteeing the smoothness of the 220V alternating-current commercial power loop, solving the problems that the LED lamp has small dimming range and flashes at low illuminance during the dimming, and realizing the effect of dimming an incandescent lamp. Low in cost, the negative resistance module can be considered as a two-terminal device without polarity.

Description

A kind of negative resistance compensating circuit

Technical field

The utility model is a kind of negative resistance circuit, belongs to the lamp power technical field.Do the negative resistance compensation when it is used for electricity-saving lamp, LED lamp light-regulating, the problems such as flicker appear in light modulation when having solved electricity-saving lamp, LED lamp light-regulating narrow range, light fixture low-light (level).

Background technology

Electricity-saving lamp is popularization and application now, and the LED light fixture is the novel green lighting electric light source, these light sources is also had the requirement of adjusting intensity of illumination." SCR light regulation device " almost all adopted in the past incandescent lamp light modulation.This SCR light regulation device can be regarded two-terminal device as, is in series with incandescent lamp and accesses the 220V electric main, and it utilizes phase control technology, change the angle of flow of industrial-frequency alternating current, also just changed the effective value of industrial-frequency alternating current output voltage, the higher incandescent lamp of effective value is brighter, realizes light modulation with this.This SCR light regulation device technology maturation, cheap is used very extensive.

After electricity-saving lamp, the LED light fixture replace incandescent, SCR light regulation device in the past is used for these light fixtures and has but become problem, and not only dimming scope narrows down, and namely illuminance change scope is little, and flicker is serious during low-light (level).A lot of world-class major companies are studied this, also developed new integrated circuit, but circuit are complicated, the high-leveled and difficult popularization of cost; Moreover SCR light regulation device manufacturer is numerous, and circuit also is not quite similar, though major company has developed new integrated circuit, can both not adapt to the SCR light regulation device of numerous manufacturers.

Summary of the invention

Illuminance appears in the utility model in the time of will solving exactly the SCR light regulation device is used for electricity-saving lamp, LED lamp light-regulating to change scope little, the serious problem of flicker during low-light (level).Its technical scheme is: design a negative resistance circuit, the input of it and LED constant-current source is together in parallel, with the SCR light regulation device access 220V electric main that is in series, realize light modulation again.

LED light fixture product needed low-voltage DC supply, power demand number watt do not wait to tens of watts, usually adopt switch power technology, and circuit is single-ended reverse exciting topology form, the 220V electric main is transformed to the low-voltage direct constant-current source lights LED.This converter is designated hereinafter simply as " LED constant-current source ", can regard it as a four-terminal network, and two inputs are the 220V electric main, two output termination LED light fixtures; Electricity-saving lamp then adopts the power supply of electric ballast technology, and fluorescent tube and electric ballast are assembled into one usually, its lamp holder is connected the 220V electric main can light.

The utility model is subject to the enlightenment of incandescent lamp light modulation principle, designed a negative resistance circuit, negative resistance circuit can be packaged into little module on the technique and use as a device, or this negative resistance circuit and " LED constant-current source " design are made of one on the same printed circuit board (PCB).This " negative resistance module " can regard two-terminal device as, need not distinguish both positive and negative polarity during application, the input of it and LED constant-current source is together in parallel, again with the SCR light regulation device access 220V electric main that is in series, shown in Figure 1 as accompanying drawing, this figure is the block diagram of LED lamp light-regulating scheme.

So-called " negative resistance module ", the voltage that adds exactly thereon is higher, and the electric current that flows through wherein is less, and is on the contrary with the characteristic of resistance commonly used.

When the voltage of powering for the LED light fixture was lower than its operating voltage threshold values, the LED point did not work, and the electric current that flows through LED is zero, was equivalent to load and disconnected, and electricity-saving lamp also is like this.If there is not negative resistance module in parallel, being equivalent to the 220V electric main does not have path, because the SCR light regulation device is connected in the 220V electric main, causes the work of SCR light regulation device not normal; And incandescent lamp is a pure resistance, even if voltage is very low, 220V electric main loop also leads to, and can not cause the work of SCR light regulation device not normal, so the incandescent lamp light modulation is transferred well.After the negative resistance module in parallel, being equivalent to 220V electric main loop has had a dummy load, and this dummy load power consumption is the smaller the better certainly.After the adjusting of SCR light regulation device, when alternating current output effective value was higher, the LED light fixture was working properly, and the electric current that this dummy load is flow through in hope is very little, even was zero better; And wish that alternating current output effective value very little electric current that still has of this dummy load when being lower than LED lamp working voltage threshold values flows through, and play one " compensation " effect, keep 220V electric main loop unobstructed.

According to such thinking, the utility model has designed a negative resistance circuit, and is with low cost, easily applies, and hereinafter will be described in detail this negative resistance circuit and how to work.Solved the light modulation problem of LED light fixture, also with regard to the corresponding light modulation problem that has solved electricity-saving lamp.

Adopt " SCR light regulation device " to electricity-saving lamp, LED lamp light-regulating, after the negative resistance module in parallel, brought good effect, it is large that illuminance changes scope, turns down the illumination light fixture and flicker also can not occur.Work good the LED constant-current source design, the LED light fixture can reach the incandescent lamp dimming effect.

Feature of the present utility model is:

1, the input of a module with negative resistance charactertistic as dummy load and LED constant-current source is in parallel, or be in parallel with electricity-saving lamp, series thyristor dimmer incoming transport civil power again, can realize preferably LED light fixture or electricity-saving lamp light modulation, this negative resistance module can be regarded a two-terminal device as, and nonpolarity divides.

2, the circuit of this negative resistance module specifically: two ac input ends of rectifier bridge VC1 namely are two terminals of negative resistance module, therefore the negative resistance module can be regarded a two-terminal device as, nonpolarity minute; Electrochemical capacitor C1 is connected on the positive and negative electrode two ends of VC1 output dc voltage; NPN triode V1 and NPN triode V3 are formed multiple tube V, the collector electrode of multiple tube V links to each other with an end of resistance R 1, the other end of R1 is connected with the positive pole of direct voltage (8), one end of the emitter of multiple tube V and resistance R 2, one end of resistance R 3 is connected, the negative pole (10) of another termination direct voltage of R2, the base stage of the other end of R3 and NPN triode V2, one end of resistance R 4, one end of capacitor C 2 is connected, the other end of C2 is connected to the negative pole (10) of direct voltage, the other end of R4 is connected with the positive pole of voltage-stabiliser tube VD1, the negative pole of VD1 is connected to the positive pole (8) of direct voltage, the base stage of multiple tube V and the collector electrode of V2, one end of resistance R 5 is connected, the other end of resistance R 5 is connected to the positive pole (8) of direct voltage, and the emitter of V2 is connected to the negative pole of direct voltage (10).

Description of drawings

Fig. 1 is the block diagram of LED lamp light-regulating scheme

Fig. 2 has replaced the negative resistance module of square frame 2 among Fig. 1 with dotted line frame 4, is a kind of physical circuit of the negative resistance module for the civil power alternating current in the dotted line frame 4.

Fig. 3 represent civil power regulate through the SCR light regulation device after the voltage waveform of output, be " unfilled corner is sinusoidal wave ", excised fore-end sinusoidal wave, wherein u is the instantaneous value of alternating current, Um and-Um is the positive and negative peak value of alternating voltage, ω t is the phase angle of alternating current.

Fig. 4 represents the voltage waveform after " unfilled corner is sinusoidal wave " rectification, and wherein u is the instantaneous value of alternating current, and Um is the peak value of alternating current, and U is mean value, and ω t is the phase angle of alternating current.

The implication that each sequence number among the figure represents is:

(1) SCR light regulation device

(2) negative resistance module

(3) LED constant-current source

Embodiment

Come description of the drawings and explanation invention of the present utility model place below in conjunction with embodiment.

A kind of physical circuit of negative resistance module in Fig. 2 dotted line frame 4.VC1 is rectifier bridge, and an one ac input end (6) is connected to an end of 220V civil power, after the other end of civil power seals in SCR light regulation device (1), is connected with another input (7) of VC1.Under the effect of SCR light regulation device (1), the alternating voltage effective value of rectifier bridge VC1 input is adjustable, and the mean value of the direct voltage of then exporting after the VC1 rectification is adjustable.But input voltage waveform has not been complete sine wave, but lacked one " unfilled corner is sinusoidal wave ", as Fig. 3 represents, VC1 is with the voltage commutation of such waveform, Fig. 4 represents the waveform after the rectification, and wherein u is the instantaneous value of alternating current, Um ,-Um is the positive and negative peak value of alternating voltage, U is mean value, and ω t is the phase angle of alternating current.

Pass through again electrochemical capacitor C1 filtering, the direct voltage output that to obtain a mean value be U, (8) are anodal, (10) are negative pole.It (is the base stage that the emitter of V3 meets V1 that NPN triode V1 and NPN triode V3 are formed multiple tube V, V1, the collector electrode interconnection of V3 is as the collector electrode of multiple tube V, the emitter as multiple tube V of the emitter of V1, the base stage of V3 is as the base stage of multiple tube V), the collector electrode of multiple tube V links to each other with an end of resistance R 1, the other end of R1 is connected with the positive pole of direct voltage (8), one end of the emitter of multiple tube V and resistance R 2, one end of resistance R 3 is connected to (9) point, the negative pole (10) of another termination direct voltage of R2, the base stage of the other end of R3 and NPN triode V2, one end of resistance R 4, one end of capacitor C 2 is connected to (11) point, the other end of C2 is connected to the negative pole (10) of direct voltage, the other end of R4 is connected with the positive pole of voltage-stabiliser tube VD1, the negative pole of VD1 is connected to the positive pole (8) of direct voltage, the base stage of multiple tube V and the collector electrode of V2, one end of resistance R 5 is connected to (12) point, the other end of resistance R 5 also is connected to the positive pole (8) of direct voltage, and the emitter of V2 also is connected to the negative pole (10) of direct voltage.Increase capacitor C 2, can improve the stability of circuit.

During work, multiple tube V provides base current through resistance R 5, resistance R 1, multiple tube V and resistance R 2 current flowings, set up voltage at R2, this voltage provides base current by resistance R 3 to triode V2, the V2 current flowing bypasses the part base current of multiple tube V, and the conducting degree of multiple tube V descends, the electric current that flows through multiple tube V reduces thereupon, so that the lower voltage on the resistance R 2, the base current that drives triode V2 reduces thereupon, and the conducting degree of V2 descends, current flowing reduces, namely be the base current that minuses shunting multiple tube V, the conducting degree of multiple tube V increases ..., so feedback reaches a balance point.

In this circuit, if do not have voltage-stabiliser tube VD1,4 two elements of resistance R, triode V1, the V3 and the triode V2 that form multiple tube V always work in linear amplification region, flow through the electric current and the electric current sum substantially constant that flows through V2 of multiple tube V, not with the size variation of applied voltage.Suitably choose the resistance of R1～R5, make the electric current that flows through multiple tube V and flow through the electric current sum of V2 in 10mA.

After adding the branch road of voltage-stabiliser tube VD1,4 two series elements of resistance R, in the situation that (8), (10) both end voltage are lower, voltage-stabiliser tube VD1 can not be breakdown, and VD1, resistance R 4 these branch roads are obstructed, are equivalent to not have voltage-stabiliser tube VD1,4 two elements of resistance R; In the situation that (8), the higher VD1 voltage stabilizing value that surpasses of (10) both end voltage, voltage-stabiliser tube VD1 is breakdown, also provide base current to triode V2 by resistance R 4, V2 conducting degree is increased, the base current of some multiple tube V poured off in many minutes, the electric current that flows through multiple tube V reduces thereupon, and circuit self power consumption is descended; When (8), the enough Gao Shike of (10) both end voltage make triode V2 saturation conduction, at this moment the saturation voltage drop between collector electrode-emitter of V2 is very little, be lower than the forward voltage drop between the base-emitter of multiple tube V, turn-off multiple tube V, the electric current that flows through only is the saturation current of triode V2, and circuit self power consumption drops to minimum.

Above analytic explanation, this circuit applied voltage is larger, and the electric current that flows through is less, i.e. and the impedance of circuit is larger, is a typical negative resistance circuit.The starting resistor of this circuit is low, and this has just guaranteed under the effect of SCR light regulation device, and a dummy load electric current also can be provided in the situation that the average electrical of output is forced down, and has kept 220V electric main path, and the SCR light regulation device can not worked not normal.

The above, it only is better enforcement example of the present utility model, be not that any pro forma restriction is done in invention, any those skilled in the art may utilize the technology contents of above-mentioned announcement to be changed or be modified to the equivalent embodiment of equivalent variations, but every technical solutions of the utility model content that do not break away from,, all still belong in the scope of technical solutions of the utility model any simple modification, equivalent variations and modification that above embodiment does according to technical spirit of the present utility model.

Claims

1. lamp light-regulating negative resistance compensating circuit, it is characterized in that: this negative resistance compensating circuit specifically: two ac input ends of rectifier bridge VC1 namely are two terminals of negative resistance module, and electrochemical capacitor C1 is connected on positive pole (8), negative pole (10) two ends of rectifier bridge VC1 output dc voltage; NPN triode V1 and NPN triode V3 are formed multiple tube V, the collector electrode of multiple tube V links to each other with an end of resistance R 1, the other end of resistance R 1 is connected with the positive pole of direct voltage (8), one end of the emitter of multiple tube V and resistance R 2, one end of resistance R 3 is connected, the negative pole (10) of another termination direct voltage of resistance R 2, the base stage of the other end of resistance R 3 and NPN triode V2, one end of resistance R 4, one end of capacitor C 2 is connected, the other end of capacitor C 2 is connected to the negative pole (10) of direct voltage, the other end of resistance R 4 is connected with the positive pole of voltage-stabiliser tube VD1, the negative pole of voltage-stabiliser tube VD1 is connected to the positive pole (8) of direct voltage, the collector electrode of the base stage of multiple tube V and NPN triode V2, one end of resistance R 5 is connected, the other end of resistance R 5 is connected to the positive pole (8) of direct voltage, and the emitter of NPN triode V2 is connected to the negative pole (10) of direct voltage.

2. lamp light-regulating negative resistance compensating circuit as claimed in claim 1, it is characterized in that: can regard a two-terminal device as with the negative resistance module of this circuit production, nonpolarity divides, during use and the input of LED constant-current source be in parallel, or be in parallel series thyristor dimmer incoming transport civil power again with electricity-saving lamp.