The Intelligent lamp charger of intelligent transportation system
Technical field
The utility model belongs to intelligent transportation field, relates to battery charger, particularly the Intelligent lamp charger of intelligent transportation system.
Background technology
LED is called as forth generation light source, there are energy-saving and environmental protection, safety, life-span length, low-power consumption, low-heat, high brightness, waterproof, miniature, shockproof, easy light modulation, light beam are concentrated, the feature such as easy maintenance, can be widely used in the fields such as various instruction, display, decoration, backlight, general lighting.
It is high that LED has electric light transformation efficiency, environmental protection, the life-span is long, operating voltage is low, repeatedly switch can't harm that life-span, volume are little, heating less, brightness is high, sturdy and durable, be easy to light modulation, color is various, light beam concentrate stable, start without advantages such as time delays, simultaneously along with the continuation of industry develops, the leap of technology breaks through, wideling popularize of application, the light efficiency of LED is also improving constantly, there is increasing charge type LED lamp in household field, such as LED flashlight, LED desk lamp, using LED as the panel computer etc. of backlight.Inevitably cause battery-heating when charging to LED supplying cell, temperature raises, and when battery temperature is too high, damages battery or damage equipment, shorten battery, the danger of blasting time serious if do not controlled to produce.
The more LED used in existing intelligent transportation system also uses supplying cell mostly; avoid the traffic jam had a power failure suddenly or short circuit brings; the charge protector of original LED directly utilizes charging device as switch usually; but no matter charging device is closed or is opened; due to gate source voltage release and foundation is similar to grid source capacitor charge and discharge; time is longer; the frequency loss of frequent charge closing pipe is larger; for situation about rising due to charging or ambient temperature, existing charging circuit does not have feedback means usually.
Utility model content
Affect battery life for temperature when overcoming the charging of existing LED supplying cell raises, the frequent switch of charging device causes switching loss greatly, react insensitive technological deficiency to ambient temperature, the utility model discloses the Intelligent lamp charger of intelligent transportation system.
The Intelligent lamp charger of intelligent transportation system described in the utility model, comprise charging triode and comparator, the emitter of described charging triode is connected with charging output by current sense resistor, the two ends of described current sense resistor are connected with two inputs of comparator respectively, also comprise Correctional tube and base voltage generation circuit, the control end of described Correctional tube is connected with the output of comparator, input and the output of Correctional tube are connected base voltage respectively and produce the output of circuit and the base stage of charging triode, described base voltage produces circuit and is formed by divider resistance and voltage stabilizing didoe series connection,
Also temperature protection circuit is parallel with between described charging transistor base and emitter; described temperature protection circuit is made up of hot thyristor and the temperature setting resistor be connected in parallel between hot thyristor positive pole and hot thyristor control end; described hot thyristor negative pole connects charging transistor emitter; positive pole connects charging transistor base, and temperature setting resistor temperature coefficient is negative.
Preferably, described charging triode base stage is connected with base stage current-limiting resistance.
Preferably, described charging triode is NPN pipe, and emitter connects the inverting input of current sense resistor one end and comparator, and the current sense resistor other end connects comparator normal phase input end and charging output, and described Correctional tube is NMOS tube.
Preferably, filter capacitor is connected with between described Correctional tube input and ground.
Preferably, the collector electrode of described charging triode is also connected with collector electrode current-limiting resistance.
Adopt the Intelligent lamp charger of intelligent transportation system described in the utility model, utilize triode as shutoff device, the shutoff of charging and restarting process speed improve, simultaneously because Correctional tube only adjusts base current size, and directly triode is not controlled, reduce the switching frequency of charging valve, thus reduce switching loss.Temperature protection circuit to Correctional tube electric current and Correctional tube operating state environmentally temperature adjust, reduce the overheated risk caused of device.
Accompanying drawing explanation
Fig. 1 is a kind of embodiment schematic diagram of the Intelligent lamp charger of intelligent transportation system described in the utility model;
In figure, Reference numeral name is called: R1-current sense resistor R2-collector electrode current-limiting resistance R3-divider resistance R4-base stage current-limiting resistance D-voltage stabilizing didoe C-filter capacitor N-NMOS pipe T-charging triode COMP-comparator CAP-battery, the brilliant casket pipe of R5-temperature setting resistor VD-heat.
Embodiment
Below in conjunction with accompanying drawing, embodiment of the present utility model is described in further detail.
The Intelligent lamp charger of intelligent transportation system described in the utility model, comprise charging triode and comparator, the emitter of described charging triode is connected with charging output by current sense resistor, the two ends of described current sense resistor are connected with two inputs of comparator respectively, also comprise Correctional tube and base voltage generation circuit, the control end of described Correctional tube is connected with the output of comparator, input and the output of Correctional tube are connected base voltage respectively and produce the output of circuit and the base stage of charging triode, described base voltage produces circuit and is formed by divider resistance and voltage stabilizing didoe series connection, described current sense resistor is positive temperature coefficient resistance.
In embodiment as shown in Figure 1, battery CAP is connected between charging input end and ground, described charging triode is NPN pipe, emitter connects the inverting input of current sense resistor one end and comparator, the current sense resistor other end connects comparator normal phase input end and charging output, and described Correctional tube is NMOS tube.
When charging current increases, pressure drop on current sense resistor R1 increases, comparator COMP two input pressure reduction increase, and anti-phase input terminal voltage is higher than normal phase input end, comparator output voltage values reduces, and NMOS tube grid voltage reduces, the pressure drop of NMOS tube N source and drain is increased, charging triode T base voltage reduces, thus reduces charging transistor collector output current, achieves negative feedback control.
According to hot thyristor characteristics, determined by the resistance be connected between its positive pole and control end, temperature setting resistor R5 resistance is larger, hot turn on thyristors temperature is lower, by setting R5 resistance, the conducting temperature of hot thyristor can be set, thus control the switch of charging triode.
When the temperature increases, according to hot thyristor operation principle, raise with temperature, threshold voltage constantly reduces, when temperature is elevated to the temperature spot of setting, and hot turn on thyristors, make short circuit between the base stage of charging triode and emitter, the VBE of charging triode T is reduced to zero, thus charging triode is closed, and charging stops.
The utility model utilizes triode as shutoff device; the shutoff of charging and restarting process speed improve; decrease the charging interval prolongation because temperature protection causes; simultaneously because Correctional tube only adjusts base current size; and directly triode is not controlled; reduce the switching frequency of charging valve, thus reduce switching loss.Temperature protection circuit to Correctional tube electric current and Correctional tube operating state environmentally temperature adjust, reduce the overheated risk caused of device.
Be reduced to fast in the process of zero at charging transistor base electric current, stray inductance on wire easily causes ripple by a relatively large margin, therefore ripple current easily causes the false triggering of charging triode, therefore can connect a base stage current-limiting resistance R4 to limit ripple current at charging transistor base, another measure being beneficial to solution ripple for connect filter capacitor C between Correctional tube input and ground.
Base resistance can be obtained by resistance string dividing potential drop, the voltage of intermediate node is exported as base voltage after adopting divider resistance R3 and voltage stabilizing didoe D to connect in the present embodiment, because the usual resistance of current sense resistor is very little, the collector electrode of charging triode can also connect collector electrode current-limiting resistance R2 and limit charging current.
Previously described is each preferred embodiment of the present utility model, preferred implementation in each preferred embodiment is if not obviously contradictory or premised on a certain preferred implementation, each preferred implementation can stack combinations use arbitrarily, design parameter in described embodiment and embodiment is only the utility model proof procedure in order to clear statement utility model people, and be not used to limit scope of patent protection of the present utility model, scope of patent protection of the present utility model is still as the criterion with its claims, the equivalent structure change that every utilization specification of the present utility model and accompanying drawing content are done, in like manner all should be included in protection range of the present utility model.