CN213368189U

CN213368189U - Constant voltage and constant current power supply circuit for LED lamp

Info

Publication number: CN213368189U
Application number: CN202022689909.6U
Authority: CN
Inventors: 郝军雷; 房艳平; 钟晓华
Original assignee: Shenzhen Kuanyue Technology Co ltd
Current assignee: Chu Xiaoneng Technology Shenzhen Co ltd
Priority date: 2020-11-19
Filing date: 2020-11-19
Publication date: 2021-06-04
Anticipated expiration: 2030-11-19

Abstract

The utility model relates to a constant voltage and constant current power supply circuit for LED lamps, which comprises a capacitance voltage reduction circuit, a rectifier, a filter capacitor, a three-terminal voltage stabilizer and a photoelectric control circuit, wherein the capacitance voltage reduction circuit comprises a capacitor connected in series in a loop and a bypass resistor connected in parallel with the capacitor; the transformer is replaced by the capacitor voltage reduction circuit consisting of the capacitor and the bypass resistor, active power is not consumed by the capacitor, and power consumed by the resistor can be ignored, so that damage caused by voltage transformation can be effectively reduced, a coil replacing a traditional transformer enables the size of a power circuit to be smaller, and finally, the photoelectric control circuit capable of automatically adjusting brightness is arranged, so that energy consumption can be further saved.

Description

Constant voltage and constant current power supply circuit for LED lamp

Technical Field

The utility model relates to a power supply circuit field specifically is constant voltage constant current power supply circuit that LED lamp was used.

Background

The LED constant current power supply mode is an ideal LED power supply mode, can avoid current change caused by the change of the forward voltage of the LED, and ensures stable brightness and longer service life of the LED by constant current. Although many manufacturers select a constant-current LED power supply at present, the LED power supply cannot be widely used due to high cost, complex equipment, inconvenience in installation and use and the like. The normal operation of the LED has high requirements on the power supply, the output of the driving power supply is required to be direct current, the voltage drop of each LED is stably kept within 3.2V-3.4V, and the current is required to be constant as much as possible.

SUMMERY OF THE UTILITY MODEL

In view of this, the present invention provides a constant voltage and constant current power circuit for an LED lamp, which can solve the problems of the prior art.

The utility model discloses a constant voltage constant current power supply circuit that LED lamp was used, including electric capacity step-down circuit, the rectifier, filter capacitor, three terminal regulator and photoelectric control circuit, electric capacity step-down circuit includes the electric capacity of concatenating in the return circuit and the shunt resistance who connects in parallel with the electric capacity, electric capacity step-down circuit's output sets gradually the rectifier, filter capacitor and photoelectric control circuit, the rectifier, filter capacitor, photoelectric control circuit connects in parallel in the return circuit in proper order, three terminal regulator sets up in the return circuit between filter capacitor and the photoelectric control circuit, photoelectric control circuit connects in parallel the position behind three terminal regulator in the return circuit, photoelectric control circuit includes resistance, photo resistance and triode, the collecting electrode and the projecting pole of triode are connected with the return circuit, photo resistance's both ends are connected with the base and the collecting electrode of triode respectively, the both ends of resistance are connected with the base and the projecting pole of triode, the collector and the emitter of the triode are output ends.

Further, the model of the three-terminal regulator is LM 7805.

Further, the rectifier is a bridge diode rectifier.

Furthermore, a plurality of LED lamp beads are arranged on the output end.

Further, the photoresistor is used for sensing ambient light.

The utility model has the advantages that: the utility model discloses a constant voltage constant current power supply circuit that LED lamp was used, (1) replaces the transformer through the electric capacity step-down circuit of constituteing by electric capacity and bypass resistance, because electric capacity does not consume active power, the power that resistance consumed can neglect to can reduce the damage that the vary voltage brought effectively, (2) replace the coil of traditional transformer make power supply circuit volume accomplish littleer, (3) set up the photoelectric control circuit that can adjust luminance by oneself and can further save energy consumption.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and it will be apparent to those skilled in the art that other related drawings can be obtained from the drawings without inventive effort.

Fig. 1 is a schematic structural diagram of the present invention.

Detailed Description

As shown in fig. 1: the constant voltage and constant current power supply circuit for the LED lamp comprises a capacitance voltage reduction circuit, a rectifier, a filter capacitor, a three-terminal regulator and a photoelectric control circuit, wherein the capacitance voltage reduction circuit comprises a capacitor C1 connected in series in a loop and a bypass resistor R1 connected in parallel with the capacitor C1, the output end of the capacitance voltage reduction circuit is sequentially provided with the rectifier, the filter capacitor C2 and the photoelectric control circuit, the rectifier, the filter capacitor C2 and the photoelectric control circuit are sequentially connected in parallel in the loop, the three-terminal regulator is arranged between the filter capacitor C2 and the photoelectric control circuit in the loop, the photoelectric control circuit is connected in parallel at a position behind the three-terminal regulator in the loop, the photoelectric control circuit comprises a resistor R3, a photoresistor R2 and a triode VT1, a collector and an emitter of the triode VT1 are connected with the loop, two ends of the photoresistor R2 are respectively connected with the base and the collector of the triode VT1, two ends of the resistor R3 are respectively connected with the, the collector and emitter of transistor VT1 are output terminals.

In this embodiment, the model of the three-terminal regulator is LM 7805.

In this embodiment, the rectifier is a bridge diode rectifier.

In this embodiment, be equipped with two LED lamp pearls on the output, be D1 and D2 respectively.

After the 220V alternating current is subjected to voltage reduction and current limitation through the capacitor C1 and the bypass resistor R1, the alternating voltage at two points A, B is about nV, the alternating voltage is rectified by the bridge diode rectifier, the direct voltage of about mV is obtained on the filter capacitor C2 and is used as the working voltage of the high-brightness light-emitting diodes D1-D2, and m is slightly smaller than n. Since the capacitor C1 does not consume active power, the power consumed by the resistor R1 is negligible.

In the embodiment, the photoresistor R2 is used for sensing ambient light, the photoelectric control circuit comprises the photoresistor R2, the resistor R3, the triode VT1 and the like, the resistance value of the photoresistor R2 rises at night, at this time, the voltage at the two ends of the filter capacitor C2 is divided by the photoresistor R2 and the resistor R3 and then provided for the direct current bias voltage of the base electrode of the triode VT1 to be very small, the triode VT1 is cut off, and the work of the LED lamp beads D1 and D2 is not affected; in daytime, due to the effect of photoelectric effect, the resistance value of the photoresistor R2 is reduced, at the moment, the triode VT1 is conducted and is close to saturation, the current passing through the capacitor C1 can only reach a specific value to the maximum extent, and due to the shunting of the triode VT1, the voltage on the filter capacitor C2 can be reduced to the specific value, so that the voltages on the LED lamp beads D1 and D2 are reduced, and energy is saved by depending on ambient light.

The utility model discloses a constant voltage constant current power supply circuit that LED lamp was used, (1) replaces the transformer through the electric capacity step-down circuit of constituteing by electric capacity and bypass resistance, because electric capacity does not consume active power, the power that resistance consumed can neglect to can reduce the damage that the vary voltage brought effectively, (2) replace the coil of traditional transformer make power supply circuit volume accomplish littleer, (3) set up the photoelectric control circuit that can adjust luminance by oneself and can further save energy consumption.

Finally, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the present invention can be modified or replaced by other means without departing from the spirit and scope of the present invention, which should be construed as limited only by the appended claims.

Claims

The constant voltage and constant current power supply circuit for the LED lamp is characterized in that: comprises a capacitance voltage-reducing circuit, a rectifier, a filter capacitor, a three-terminal regulator and a photoelectric control circuit, wherein the capacitance voltage-reducing circuit comprises a capacitor connected in series in a loop and a bypass resistor connected in parallel with the capacitor, the output end of the capacitance voltage-reducing circuit is sequentially provided with the rectifier, the filter capacitor and the photoelectric control circuit, the rectifier, the filter capacitor and the photoelectric control circuit are sequentially connected in parallel in the loop, the three-terminal regulator sets up between filter capacitor and photoelectric control circuit in the return circuit, photoelectric control circuit connects in parallel the position behind the three-terminal regulator in the return circuit, photoelectric control circuit includes resistance, photo resistance and triode, the collecting electrode and the projecting pole of triode are connected with the return circuit, photo resistance's both ends are connected with the base and the collecting electrode of triode respectively, the both ends of resistance are connected with the base and the projecting pole of triode respectively, the collecting electrode and the projecting pole of triode are the output.
2. The constant voltage and constant current power supply circuit for an LED lamp according to claim 1, wherein: the model of the three-terminal regulator is LM 7805.
3. The constant voltage and constant current power supply circuit for an LED lamp according to claim 1, wherein: the rectifier is a bridge diode rectifier.
4. The constant voltage and constant current power supply circuit for an LED lamp according to claim 1, wherein: and an LED driving chip is arranged on the output end, and an output pin of the LED driving chip is provided with a plurality of LED lamp beads.
5. The constant voltage and constant current power supply circuit for an LED lamp according to claim 1, wherein: the photoresistor is used for sensing ambient light.