CN202190446U

CN202190446U - LED light power source

Info

Publication number: CN202190446U
Application number: CN2011202992107U
Authority: CN
Inventors: 何志雄
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-08-17
Filing date: 2011-08-17
Publication date: 2012-04-11
Anticipated expiration: 2021-08-17

Abstract

The utility model provides an LED light power source including a rectification circuit. A positive output terminal of the rectification circuit is connected to one end of a first capacitor. The other end of the first capacitor is connected to one end of a resistor and a collector of a first transistor. The other end of the first resistor and a base of the first transistor are connected to a collector of a second transistor. An emitting electrode of the first transistor is connected to a base of the second transistor and one end of a second resistor. An emitting electrode of the second transistor and the other end of the second resistor are connected to a negative terminal of the rectification circuit. The two ends of the first capacitor are used for connecting an output terminal of an LED light string. The LED light power source in the utility model has energy efficiency higher than 98 percents. And by using the LED light power source in the utility model, the starting impact of a capacitor voltage reducing circuit is avoided.

Description

LED lamp power supply

Technical field

The utility model relates to light-emitting diode (lighting emitting diode is called for short LED) technical field, relates in particular to a kind of lamp of LED efficiently power supply.

Background technology

LED has obtained extensive popularizing at lighting field, and it has plurality of advantages such as environmental protection, energy-conservation, long service life.The LED power technology is that LED obtains one of important support technology of popularizing on a large scale, and present LED lamp power supply exists not high enough, the suitable narrower shortcoming of voltage range of efficient.

Summary of the invention

The purpose of the utility model is to provide a kind of LED lamp power supply, and the efficient that exists with the solution prior art has much room for improvement, is suitable for the narrow problem of voltage range.

In order to address the above problem; A kind of LED lamp power supply that the utility model provides comprises rectification circuit; The positive output end of said rectified current is connected in an end of one first electric capacity; The other end of said first electric capacity is connected in an end of one first resistance and the collector electrode of a first transistor; The other end of said first resistance and the base stage of said the first transistor are connected in the collector electrode of a transistor seconds, and the emitter of said the first transistor is connected in the base stage of said transistor seconds and an end of one second resistance, and the other end of the emitter of said transistor seconds and said second resistance is connected in the negative output terminal of said rectification circuit; Wherein, the two ends of said first electric capacity are the output that is used to connect LED lamp string.

In order to address the above problem; The another kind of LED lamp power supply that the utility model provides comprises rectification circuit; The positive output end of said rectified current is connected in an end of one first electric capacity, an end of one first resistance and the collector electrode of a first transistor; The other end of said first resistance and the base stage of said the first transistor are connected in the collector electrode of a transistor seconds; The emitter of said the first transistor is connected in the base stage of said transistor seconds and an end of one second resistance; The emitter of said transistor seconds is connected with the other end of said second resistance, and the other end of said first electric capacity is connected in the negative output terminal of said rectification circuit, and the emitter of said transistor seconds is the output that is used to be connected LED lamp string with the negative output terminal of said rectification circuit.

In order to address the above problem; Another LED lamp power supply that the utility model provides comprises rectification circuit; The positive output end of said rectified current is connected in an end of one first electric capacity, an end of one first resistance and the collector electrode of a first transistor; The other end of said first resistance and the base stage of said the first transistor are connected in the collector electrode of a transistor seconds; The emitter of said transistor seconds and base stage are connected in the two ends of one second resistance; The other end of said first electric capacity is connected in the negative output terminal of said rectification circuit, and the emitter of the emitter of said transistor seconds and the negative output terminal of said rectification circuit and said the first transistor and the base stage of said transistor seconds are the output that is used to be connected LED lamp string.

According to a kind of preferred implementation of above-mentioned LED lamp power supply, wherein, an input of said rectification circuit one second electric capacity of connecting.

According to a kind of preferred implementation of above-mentioned LED lamp power supply, wherein, said rectified current is a full-wave bridge rectifier circuit.

According to a kind of preferred implementation of above-mentioned LED lamp power supply, wherein, said first electric capacity is for there being electrode capacitance.

According to a kind of preferred implementation of above-mentioned LED lamp power supply, wherein, said the first transistor, transistor seconds are NPN transistor.

Through comprising the application of the transistorized current-limiting circuit of current limliting, the utility model not only has up to the energy efficiency more than 98%, and can avoid the start of capacity voltage dropping circuit to impact.

Description of drawings

Fig. 1 is the electrical block diagram of the utility model preferred embodiment one;

Fig. 2 is the electrical block diagram of the utility model preferred embodiment two;

Fig. 3 is the electrical block diagram of the utility model preferred embodiment three;

Fig. 4 is the electrical block diagram of the utility model preferred embodiment four.

Embodiment

Below in conjunction with accompanying drawing and embodiment the utility model is explained further details.

Explanation is in advance, and for the application of the utility model clearly is described, Fig. 1-preferred embodiment shown in Figure 4 is connected with LED lamp string LED1 or LED2, but the protection range of the utility model does not comprise lamp string LED1, LED2.

Fig. 1 shows the circuit theory of the utility model preferred embodiment one; Shown in it; The rectification circuit of the preferred embodiment one is the full-wave bridge rectifier circuit of being made up of diode D1, D2, D3, D4, and the positive output end of this rectified current also is the negative electrode of diode D1, D3; Be connected in an end of first capacitor C 1 and the positive pole of lamp string LED1, wherein first capacitor C 1 is for there being electrode capacitance.The other end of first capacitor C 1 is connected in an end of first resistance R 1 and the collector electrode of the first transistor Q1.Simultaneously, this end of first resistance R 1 is connected with the negative pole of the collector electrode of the first transistor Q1 with lamp string LED1, and in brief, the two ends of first capacitor C 1 are the output that is used to connect lamp string LED1, and also promptly, lamp string LED1 is parallelly connected with first capacitor C 1.The base stage of the other end of first resistance R 1 and the first transistor Q1 is connected in the collector electrode of transistor seconds Q2; The emitter of the first transistor Q1 is connected in an end of the base stage and second resistance R 2 of transistor seconds Q2; The other end of the emitter of transistor seconds Q2 and second resistance R 2 is connected in the negative output terminal of rectification circuit, also is the positive pole of diode D2, D4.

In this preferred embodiment one; Diode D1, D2, D3, D4 form rectification circuit; The transistor Q1 of NPN type, Q2 and resistance R 1, R2 form current-limiting circuit; Electric current inputs to lamp string LED1 via rectification circuit, and electric current produces bias voltage to drive the first transistor Q1 conducting through first resistance R 1, and second resistance R 2 detects the electric current of flowing through lamps string LED1.If the electric current on second resistance R 2 surpasses cut-off current; Pressure drop on second resistance R 2 will surpass the conducting voltage of transistor seconds Q2; Transistor seconds Q2 conducting, thus control gets into the electric current of the base stage of the first transistor Q1, and the first transistor Q1 ducting capacity descends; The electric current that flows through on second resistance R 2 descends thereupon, reaches the constant current set point.Hence one can see that, when line voltage is higher than standard value or owing to the reason of lamp string LED1 causes electric current, rises, and the first transistor Q1 gets into the Current limited Control state; When line voltage is lower than standard value, the complete conducting of the first transistor Q1, the loss of this preferred embodiment one is extremely low, and energy efficiency can reach more than 98%, and can solve the start impact of capacity voltage dropping circuit simultaneously.

Compare with preferred embodiment one shown in Figure 1, in the preferred embodiment of Fig. 2-shown in Figure 4, on the input terminal of rectification circuit, increase by one second capacitor C 2, form capacity voltage dropping circuit, to improve the scope that lamp string LED1 adapts to voltage.

In preferred embodiment shown in Figure 3 three, current-limiting circuit and lamp string LED1 change, and whereby, transistor seconds Q2 can be integrated in the circuit board, shown in frame of broken lines with lamp string LED1.Utilize the positive temperature characterisitic of transistor seconds Q2 to control electric current and the temperature of lamp string LED1.When the circuit board temperature rising of lamp string LED1, transistor seconds Q2 conducting strengthens, and shunting increases, and reduces the conducting of the first transistor Q1, and reduction gets into the electric current of lamp string LED1, thereby reaches the purpose of temperature control.

In preferred embodiment shown in Figure 4 four; The lamp string comprises two parts, and a part is lamp string LED1, and another part then is lamp string LED2; The position of lamp string LED1 is identical with preferred embodiment three; The two ends of lamp string LED2 are connected between the base stage of emitter and transistor seconds Q2 of the first transistor Q1, can increase the ability that transistor seconds Q2 closes the first transistor Q1 like this, and transistor seconds Q2 can be by the replacement of the chip the TL431 that produces such as Texas Instrument.

In sum, the utility model not only efficient is greatly improved, and has other multiple advantages, the scope that for example avoid the start of capacity voltage dropping circuit to impact, raising lamp string adapts to voltage, temperature control etc.

Can know that by technological general knowledge the utility model can be realized through other the embodiment that does not break away from its spirit or essential feature.Therefore, above-mentioned disclosed embodiment with regard to each side, all just illustrates, and is not only.All in the utility model scope or the change that is being equal in the scope of the utility model all comprised by the utility model.

Claims

1. LED lamp power supply; Comprise rectification circuit; It is characterized in that; The positive output end of said rectified current is connected in an end of one first electric capacity, and the other end of said first electric capacity is connected in an end of one first resistance and the collector electrode of a first transistor, and the other end of said first resistance and the base stage of said the first transistor are connected in the collector electrode of a transistor seconds; The emitter of said the first transistor is connected in the base stage of said transistor seconds and an end of one second resistance; The other end of the emitter of said transistor seconds and said second resistance is connected in the negative output terminal of said rectification circuit, and wherein, the two ends of said first electric capacity are the output that is used to connect LED lamp string.

2. LED lamp power supply; Comprise rectification circuit; It is characterized in that; The positive output end of said rectified current is connected in an end of one first electric capacity, an end of one first resistance and the collector electrode of a first transistor, and the other end of said first resistance and the base stage of said the first transistor are connected in the collector electrode of a transistor seconds, and the emitter of said the first transistor is connected in the base stage of said transistor seconds and an end of one second resistance; The emitter of said transistor seconds is connected with the other end of said second resistance; The other end of said first electric capacity is connected in the negative output terminal of said rectification circuit, and wherein, the emitter of said transistor seconds is the output that is used to be connected LED lamp string with the negative output terminal of said rectification circuit.

3. LED lamp power supply; Comprise rectification circuit; It is characterized in that; The positive output end of said rectified current is connected in an end of one first electric capacity, an end of one first resistance and the collector electrode of a first transistor; The other end of said first resistance and the base stage of said the first transistor are connected in the collector electrode of a transistor seconds, and the emitter of said transistor seconds and base stage are connected in the two ends of one second resistance, and the other end of said first electric capacity is connected in the negative output terminal of said rectification circuit; Wherein, the base stage of the emitter of the negative output terminal of the emitter of said transistor seconds and said rectification circuit and said the first transistor and said transistor seconds is the output that is used to be connected LED lamp string.

4. according to claim 1,2 or 3 described LED lamp power supplys, it is characterized in that an input of said rectification circuit one second electric capacity of connecting.

5. according to claim 1,2 or 3 described LED lamp power supplys, it is characterized in that said rectified current is a full-wave bridge rectifier circuit.

6. according to claim 1,2 or 3 described LED lamp power supplys, it is characterized in that said first electric capacity is for there being electrode capacitance.

7. according to claim 1,2 or 3 described LED lamp power supplys, it is characterized in that said the first transistor, transistor seconds are NPN transistor.