CN202310223U

CN202310223U - Stable-sampling-voltage LED (light-emitting diode) constant-current drive power source

Info

Publication number: CN202310223U
Application number: CN2011204248135U
Authority: CN
Inventors: 梁妙娟
Original assignee: FOSHAN NANHAI HOLDSUN ELECTRONICS CO LTD
Current assignee: FOSHAN NANHAI HOLDSUN ELECTRONICS CO LTD
Priority date: 2011-11-01
Filing date: 2011-11-01
Publication date: 2012-07-04
Anticipated expiration: 2021-11-01

Abstract

The utility model provides a stable-sampling-voltage LED (light-emitting diode) constant-current drive power source which comprises a power-factor control circuit, a pulse-width modulation control circuit, a current/voltage detection circuit, an optical coupler, a first isolating transformer, a second isolating transformer, a first rectifier and filter circuit, a second rectifier and filter circuit, a rectifier circuit and an output current sampling circuit, wherein the output current sampling circuit is mainly composed of at least two electrolytic capacitors and a sampling resistor, and the sampling resistor is connected between the electrolytic capacitors in series. By adopting the output current sampling circuit composed of the electrolytic capacitors and the sampling resistor, the utility model has the advantages of small ripple, stable current, stable sampling voltage and the like, so that the LED lamp can operate normally and can not have the phenomenon of stroboflash.

Description

The LED constant-current driving power supply that a kind of sampling voltage is stable

Technical field

The utility model relates to the technical field of electronic circuit, refers in particular to the stable LED constant-current driving power supply of a kind of sampling voltage.

Background technology

Convention in the industry, the ripple of the sample circuit of traditional LED constant-current driving power supply are difficult to control, and be bigger under the actual conditions; Easy like this its electric current that causes is unstable, and sampling voltage is unstable, thereby makes the LED lamp luminous undesired; Through regular meeting stroboscopic phenomenon taking place, badly influences the daily life illumination.

Summary of the invention

The purpose of the utility model is to overcome the deficiency of prior art, provides a kind of reliable sampling voltage reasonable in design stable LED constant-current driving power supply.

For realizing above-mentioned purpose; The technical scheme that the utility model provided is: the LED constant-current driving power supply that a kind of sampling voltage is stable; It includes power factor control circuit, control circuit for pulse-width modulation, current/voltage testing circuit, optocoupler, first isolating transformer, second isolating transformer, first current rectifying and wave filtering circuit, second current rectifying and wave filtering circuit, rectification circuit and output current sample circuit; Wherein, The primary input terminal of described first isolating transformer is connected to first current rectifying and wave filtering circuit and second current rectifying and wave filtering circuit, and the secondary output end of this first isolating transformer is connected in power factor control circuit simultaneously; First current rectifying and wave filtering circuit, power factor control circuit, control circuit for pulse-width modulation join successively, and this control circuit for pulse-width modulation and second current rectifying and wave filtering circuit are connected to the primary input terminal of second isolating transformer simultaneously; The secondary output end of this second isolating transformer is connected with the rectification circuit that is connected with the output current sample circuit; This output current sample circuit is connected in the current/voltage testing circuit simultaneously, and this current/voltage testing circuit is connected with control circuit for pulse-width modulation through optocoupler; Described output current sample circuit mainly is made up of electrolytic capacitor and sample resistance, and wherein, described electrolytic capacitor has two at least, and sample resistance is serially connected between the electrolytic capacitor.

The utility model is after having adopted such scheme; Its great advantage is that the utility model is through adopting the output current sample circuit of being made up of electrolytic capacitor and sample resistance; Realized that ripple is little, beneficial effect such as current stabilization, sampling voltage are level and smooth; Make and the normal operation of LED lamp ability stroboscopic phenomenon can not take place.

Description of drawings

Fig. 1 is the circuit theory diagrams of the utility model.

Embodiment

Below in conjunction with specific embodiment the utility model is described further.

Shown in accompanying drawing 1; The LED constant-current driving power supply that the described sampling voltage of present embodiment is stable; It includes power factor control circuit PFC, control circuit for pulse-width modulation PWM, current/voltage testing circuit 1, optocoupler PH, the first isolating transformer T1, the second isolating transformer T2, first current rectifying and wave filtering circuit 2, second current rectifying and wave filtering circuit 3, rectification circuit 4 and output current sample circuit 5; Wherein, The primary input terminal of the described first isolating transformer T1 is connected to first current rectifying and wave filtering circuit 2 and second current rectifying and wave filtering circuit 3, and the secondary output end of this first isolating transformer T1 is connected in power factor control circuit PFC simultaneously; First current rectifying and wave filtering circuit 2, power factor control circuit PFC, control circuit for pulse-width modulation PWM join successively, and this control circuit for pulse-width modulation PWM and second current rectifying and wave filtering circuit 3 are connected to the primary input terminal of the second isolating transformer T2 simultaneously; The secondary output end of this second isolating transformer T2 is connected with the rectification circuit that is connected with output current sample circuit 54; This output current sample circuit 5 is connected in current/voltage testing circuit 1 simultaneously, and this current/voltage testing circuit 1 is connected with control circuit for pulse-width modulation PWM through optocoupler PH; Wherein, the described output current sample circuit 5 of present embodiment mainly is made up of electrolytic capacitor E and sample resistance R, wherein; Described electrolytic capacitor E has two; Be respectively electrolytic capacitor E1 and electrolytic capacitor E2, simultaneously sample resistance R is serially connected between this electrolytic capacitor E1 and the electrolytic capacitor E2, and such design makes that the ripple of output current sample circuit 5 is little, current stabilization, sampling voltage are level and smooth; Thereby make the normal operation of LED lamp ability; Stroboscopic phenomenon can not take place, overcome the drawback that traditional design is brought well, be worthy to be popularized.

The embodiment of the above is the preferred embodiment of the utility model only, is not the practical range that limits the utility model with this, so the variation that all shapes according to the utility model, principle are done all should be encompassed in the protection range of the utility model.

Claims

1. LED constant-current driving power supply that sampling voltage is stable; It includes power factor control circuit (PFC), control circuit for pulse-width modulation (PWM), current/voltage testing circuit (1), optocoupler (PH), first isolating transformer (T1), second isolating transformer (T2), first current rectifying and wave filtering circuit (2), second current rectifying and wave filtering circuit (3), rectification circuit (4) and output current sample circuit (5); Wherein, The primary input terminal of described first isolating transformer (T1) is connected to first current rectifying and wave filtering circuit (2) and second current rectifying and wave filtering circuit (3), and the secondary output end of this first isolating transformer (T1) is connected in power factor control circuit (PFC) simultaneously; First current rectifying and wave filtering circuit (2), power factor control circuit (PFC), control circuit for pulse-width modulation (PWM) join successively, and this control circuit for pulse-width modulation (PWM) and second current rectifying and wave filtering circuit (3) are connected to the primary input terminal of second isolating transformer (T2) simultaneously; The secondary output end of this second isolating transformer (T2) is connected with the rectification circuit that is connected with output current sample circuit (5) (4); This output current sample circuit (5) is connected in current/voltage testing circuit (1) simultaneously, and this current/voltage testing circuit (1) is connected with control circuit for pulse-width modulation (PWM) through optocoupler (PH); It is characterized in that: described output current sample circuit (5) mainly is made up of electrolytic capacitor (E) and sample resistance (R), and wherein, described electrolytic capacitor (E) has two at least, and sample resistance (R) is serially connected between the electrolytic capacitor (E).