CN204259228U

CN204259228U - A kind of PWM circuit of LED dimming power source

Info

Publication number: CN204259228U
Application number: CN201420708915.3U
Authority: CN
Inventors: 赖小红
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-11-21
Filing date: 2014-11-21
Publication date: 2015-04-08
Anticipated expiration: 2024-11-21

Abstract

The utility model relates to field of illumination lamp technology, especially a kind of PWM circuit of LED dimming power source.It comprises the light-sensitive element for intensity of illumination in induced environment; For gathering the luminance signal value the microprocessor compared two signal values that the working current value of load and light-sensitive element export; The pwm chip be connected with microprocessor by light driver for isolating and the PWM modulation signal for exporting according to pwm chip carry out the power switch pipe of the size of the input current value of control load.Light signal reception technique and PWM modulation technology have been carried out effective fusion by the utility model, make circuit structure can be applied to LED brightness adjustment control, can realize continuity regulable control by PWM; Its circuit structure is simple, and the intelligent dimming for LED controls to provide hardware foundation, has very strong practicality.

Description

A kind of PWM circuit of LED dimming power source

Technical field

The utility model relates to field of illumination lamp technology, especially a kind of PWM circuit of LED dimming power source.

Background technology

Along with the shortage increasingly of the energy, development energy saving environmental protection product has become the common recognition of entire society, in order to reach the object of energy-conserving and environment-protective, human body sensing desk lamp with dimmer switch obtains and applies increasingly extensively in light fixture, especially in the public domain such as corridor, stair, when ambient brightness is low, if there is people movable, automatically turns on lamp for people and illumination is provided; If unmanned, then automatically close lamp, namely while providing illumination to people, play certain energy-conserving action.

In field of lamp illumination, in order to reach energy-conservation object, the LED of the luminous high efficiency of use, energy-saving and environmental protection is usually as lighting; Therefore, be necessary to provide a kind of signal processing circuit being applicable to LED brightness adjustment control, to pass through finally to realize LED brightness adjustment control effective control of induced signal.

Utility model content

For the deficiency that above-mentioned prior art exists, the purpose of this utility model is to provide the PWM circuit that a kind of circuit structure is simple, output signal continous-stable, can provide the LED dimming power source of hardware foundation for the intelligent dimming of LED.

To achieve these goals, the utility model adopts following technical scheme:

A PWM circuit for LED dimming power source, it comprises

For the light-sensitive element of intensity of illumination in induced environment;

For gathering the luminance signal value the microprocessor compared two signal values that the working current value of load and light-sensitive element export;

By the pwm chip that light driver for isolating is connected with microprocessor;

With

PWM modulation signal for exporting according to pwm chip carrys out the power switch pipe of the size of the input current value of control load.

Preferably, described smooth driver for isolating is MOC3020 type optocoupler, the first resistance is connected with between first pin of described smooth driver for isolating and No. second pin, first pin of described smooth driver for isolating connects the VDD pin of microprocessor, the PWM pin of the second pin connection microprocessor by the second resistance, and the 6th pin of described smooth driver for isolating is connected the TM pin of pwm chip respectively by the 3rd resistance, connected the VIN pin of pwm chip by the 4th resistance;

The 7th resistance that the grid of described power switch pipe is connected pwm chip by the 5th resistance of connecting successively DRV pin passing through with the 6th resistance is connected successively and the 8th grounding through resistance, the source electrode of described power switch pipe connects load by the 9th grounding through resistance, drain electrode, and the two ends of described 6th resistance are parallel with the first diode.

Preferably, it also comprises the RCD absorptive unit that is connected to load input terminal, and the drain electrode of described power switch pipe connects load by RCD absorptive unit;

Described RCD absorptive unit comprises the tenth resistance, the second diode and the 11 resistance of connecting successively, and the two ends of described tenth resistance are parallel with the first electric capacity.

Preferably, described microprocessor comprises a STM8S103 type single-chip microcomputer, and described pwm chip is SY5800A type isolation drive chip.

Owing to have employed such scheme, light signal reception technique and PWM modulation technology have been carried out effective fusion by the utility model, make circuit structure can be applied to LED brightness adjustment control, can realize continuity regulable control by PWM; Its circuit structure is simple, and the intelligent dimming for LED controls to provide hardware foundation, has very strong practicality.

Accompanying drawing explanation

Fig. 1 is the system principle diagram of the utility model embodiment;

Fig. 2 is the circuit structure diagram of the utility model embodiment;

Fig. 3 is that the circuit in actual applications of the utility model embodiment connects with reference to figure mono-;

Fig. 4 is that the circuit in actual applications of the utility model embodiment connects with reference to figure bis-.

Embodiment

Below in conjunction with accompanying drawing, embodiment of the present utility model is described in detail, but the multitude of different ways that the utility model can be defined by the claims and cover is implemented.

As depicted in figs. 1 and 2 and composition graphs 3, the PWM circuit of a kind of LED dimming power source that the present embodiment provides, it comprises:

Light-sensitive element 1, it is for the environment illumination intensity responded in certain limit and be converted to the signal of telecommunication, can be made up of electronic components such as photo resistance;

Microprocessor 2, it is for the luminance signal value (namely corresponding value of electrical signals) that gathers the working current value of load (i.e. LED) and light-sensitive element 1 and export and compare two signal values, finally to be realized the duty ratio of adjustment pwm signal by comparative result;

Pwm chip U1, it is connected with microprocessor 2 by light driver for isolating U3;

With

Power switch pipe Q1, it carrys out the size of the input current value of control load for the PWM modulation signal exported according to pwm chip U1.

So, light signal reception technique and PWM modulation technology can be carried out good combination by said structure, thus realize the brightness adjustment control to load; Meanwhile, utilize microprocessor 2 to realize the setting of load operating mode by the mode of programming, the intelligent dimming for load controls to provide hardware foundation.

For simplifying the structure of whole circuit to greatest extent, and ensure the functional effect of circuit, the light driver for isolating U3 of the present embodiment can adopt MOC3020 type optocoupler; Wherein, the first resistance R1 is connected with between first pin of light driver for isolating U3 and No. second pin, first pin of light driver for isolating U3 connects the VDD pin of microprocessor 2, the PWM pin of the second pin connection microprocessor 2 by the second resistance R2, and the 6th pin of light driver for isolating U3 is connected the TM pin of pwm chip U1 respectively by the 3rd resistance R3, connected the VIN pin of pwm chip U1 by the 4th resistance R4;

The 7th resistance R7 that the grid of power switch pipe Q1 is then connected pwm chip U1 by the 5th resistance R5 connected successively DRV pin passing through with the 6th resistance R6 is connected successively and the 8th resistance R8 ground connection, the source electrode of power switch pipe Q1 connects load by the 9th resistance R9 ground connection, drain electrode, is parallel with the first diode D1 at the two ends of the 6th resistance R6 simultaneously.So, the break-make of power switch pipe can be utilized to coordinate corresponding electronic devices and components, as inductance, electric capacity etc., realize powering to the energy storage type of load, then can be conducive to regulating the continuity of load current by PWM mode.

For being conducive to the rate of climb slowing down voltage when power switch pipe Q1 turns off, reduce turn-off power loss; Meanwhile, ceiling voltage when power-limiting switching tube Q1 pipe turns off, prevents power switch pipe Q1 from damaging because turning off overvoltage.The modulation circuit of the present embodiment also comprises the RCD absorptive unit that is connected to load input terminal, and the drain electrode of power switch pipe Q1 connects load by RCD absorptive unit; The RCD absorptive unit of the present embodiment comprises the tenth resistance R10, the second diode D2 and the 11 resistance R11 that connect successively, and the two ends of the tenth resistance R10 are parallel with the first electric capacity C1.

In addition, for optimizing the performance of whole circuit to greatest extent, the microprocessor 2 of the present embodiment comprises a STM8S103 type single-chip microcomputer, and pwm chip U1 then adopts SY5800A type isolation drive chip.The modulation circuit of the present embodiment, when applying, can carry out circuit structure design with reference to figure 3, to embody its functional effect.

The foregoing is only preferred embodiment of the present utility model; not thereby the scope of the claims of the present utility model is limited; every utilize the utility model specification and accompanying drawing content to do equivalent structure or equivalent flow process conversion; or be directly or indirectly used in other relevant technical fields, be all in like manner included in scope of patent protection of the present utility model.

Claims

1. a PWM circuit for LED dimming power source, is characterized in that: it comprises

With

2. the PWM circuit of a kind of LED dimming power source as claimed in claim 1, it is characterized in that: described smooth driver for isolating is MOC3020 type optocoupler, the first resistance is connected with between first pin of described smooth driver for isolating and No. second pin, first pin of described smooth driver for isolating connects the VDD pin of microprocessor, the PWM pin of the second pin connection microprocessor by the second resistance, and the 6th pin of described smooth driver for isolating is connected the TM pin of pwm chip respectively by the 3rd resistance, connected the VIN pin of pwm chip by the 4th resistance;

3. the PWM circuit of a kind of LED dimming power source as claimed in claim 1 or 2, is characterized in that: it also comprises the RCD absorptive unit that is connected to load input terminal, and the drain electrode of described power switch pipe connects load by RCD absorptive unit;

4. the PWM circuit of a kind of LED dimming power source as claimed in claim 3, is characterized in that: described microprocessor comprises a STM8S103 type single-chip microcomputer, and described pwm chip is SY5800A type isolation drive chip.