CN201731275U

CN201731275U - Intelligent light-adjusting flashlight capable of adjusting light intensity

Info

Publication number: CN201731275U
Application number: CN2010202049664U
Authority: CN
Inventors: 刘占波; 于景宾; 陈忠
Original assignee: SHENZHEN SOLAR-LED LIGHTING TECHNOLOGY Co Ltd
Current assignee: SHENZHEN SOLAR-LED LIGHTING TECHNOLOGY Co Ltd
Priority date: 2010-05-24
Filing date: 2010-05-24
Publication date: 2011-02-02
Anticipated expiration: 2020-05-24

Abstract

The utility model discloses an intelligent light-adjusting flashlight capable of adjusting the light intensity, which comprises a reference voltage, a single chip microcomputer, a BOOST boosted circuit, an LED and a current detecting circuit, wherein the LED is connected with a small resister in series, the single chip microcomputer outputs a PWM signal to control the BOOST boosted circuit after comparing the reference voltage with the power supply voltage, the BOOST boosted circuit outputs to drive the LED, and the current detecting circuit detects the voltage of the small resister which is connected with the LED in series and feeds the voltage back to the single chip microcomputer to adjust the PWM duty ratio. The intelligent light-adjusting electric flashlight not only detects the output voltage by a 12 bit high-speed A/D conversion port of the Hetai single chip microcomputer to be fast in speed and high in precision, but also adjusts the current of the LED by controlling the PWM duty ratio to be capable of continuously adjusting the current.

Description

The intelligent dimming torch of variable intensity

Technical field

The utility model relates to the electric drive technical field, relates to the actuation techniques field of Led torch specifically.

Background technology

At present, the constant current chip of known torch generally adopts the mode of mirror-image constant flow source, amplified current comes driving LED, perhaps allow the current constant of LED by voltage raising and reducing and feedback resistance, but, be inconvenient to regulate the electric current of LED like this, especially in booster circuit, battery as 3V is given single led power supply by the constant current IC that boosts, and constant current is set in 700mA, if we need the electric current of 350mA, usually can only allow the waveform of certain frequency 50% dutycycle control the Enable Pin of LED, utilize the persistence characteristic of human eye to regulate LED brightness, but as running into the situation of battery electric quantity deficiency, in the time of 50%LED conducting, cell voltage can be dragged down, do not provide the 700mA electric current in the LED ON time, this moment just can't constant current, and the defective value of described prior art must improve.

The utility model content

The purpose of this utility model is at above-mentioned technological deficiency, and a kind of intelligent dimming torch of variable intensity is provided, and the intelligent dimming torch of this variable intensity can not only constant current be regulated LED brightness continuously, and the control accuracy height.

The technical solution of the utility model is as described below: comprise reference voltage, single-chip microcomputer, BOOST booster circuit, LED, current detection circuit, the described LED small resistor of connecting, after reference voltage compares supply voltage, single-chip microcomputer output pwm signal control BOOST booster circuit, BOOST booster circuit output driving LED, behind the voltage of the small resistor of current detection circuit detection LED series connection, feed back to single-chip microcomputer and adjust the PWM dutycycle.

According to the utility model of said structure, its beneficial effect is that the utility model has not only adopted 12 high-speed a/d conversion mouths that close safe single-chip microcomputer to detect output voltage, and speed is fast and precision is high; And by control PWM duty recently regulate the LED electric current, electric current can be regulated continuously.

Description of drawings

Accompanying drawing 1 is a block diagram of the present utility model;

Accompanying drawing 2 is the circuit theory diagrams of the utility model one specific embodiment.

Reference voltage in the drawings, 1; 2, single-chip microcomputer; 3, BOOST booster circuit; 4, LED; 5, current detection circuit.

The specific embodiment

Below in conjunction with accompanying drawing and embodiment the utility model is further described:

As shown in Figure 1, comprise reference voltage 1, single-chip microcomputer 2, BOOST booster circuit 3, LED4, current detection circuit 5, the described LED4 small resistor of connecting, the reference voltage 1 of single-chip microcomputer 2 by comparing supply voltage and changing through A/D, detect supply voltage, if supply voltage is low excessively, reduce output current or shutdown.Single-chip microcomputer 2 output pwm signals control BOOST booster circuit 3, BOOST booster circuit 3 output driving LED 4, the voltage that current detection circuit 5 detects the small resistor that LED4 connected detects the electric current of LED4, feed back to single-chip microcomputer 2 again and adjust the PWM dutycycle, the output voltage of control BOOST booster circuit 3, thereby regulate the electric current of LED2, LED2 is the load of BOOST booster circuit 3, when the electric current of LED2 because voltage pulsation is when reducing, this moment the reducing and can be detected of electric current by single-chip microcomputer 2, single-chip microcomputer can increase the output duty cycle D of PWM, according to output voltage U o=Ui*D, output voltage can increase, and electric current can recover initial value, and vice versa.But the LED2 constant current also can be regulated output current continuously.

As shown in Figure 2, present embodiment adopts the lithium electricity power supply of 3.3V, and output pwm signal is given metal-oxide-semiconductor Q2 when single-chip microcomputer 2 detects operation, when the Q2 conducting, VCC gives inductance L 2 chargings, and when ending, the induced voltage of L2 is superimposed with the voltage of battery, open metal-oxide-semiconductor Q1 simultaneously, through capacitor C 1 filtering,, detect the electric current of LED2 by the voltage on the detection resistance R 4 to the LED2 power supply, if the LED2 electric current is excessive or too small, by adjusting the dutycycle of PWM, adjust the induced voltage of inductance, thereby adjust the cathode voltage of C4, thereby control LED2 electric current diminishes or becomes big, realize constant current, as from the foregoing, also can be by adjusting the dutycycle of PWM, realize light modulation, adjust the brightness of LED2.

The effect of each part mentioned above is as follows:

1, this metal-oxide-semiconductor of Q2:PWM output control gives inductance L 2 chargings.

2, Q1: open and thoroughly close torch.

3, U2 and R3: constitute voltage reference signal, thereby detect the voltage of battery.

Though the utility model is described with reference to the above embodiments; but those of ordinary skill in the art can recognize very clearly that fully above embodiment is used to illustrate the utility model; wherein can make variations and modifications and not break away from the utility model in a broad sense; so be not that conduct is to qualification of the present utility model; as long as in connotation scope of the present utility model, all will fall within the protection domain that the utility model requires variation, the distortion of above-described embodiment.

Claims

1. the intelligent dimming torch of a variable intensity, comprise reference voltage, single-chip microcomputer, BOOST booster circuit, LED, current detection circuit, it is characterized in that: the described LED small resistor of connecting, after reference voltage compares supply voltage, single-chip microcomputer output pwm signal control BOOST booster circuit, BOOST booster circuit output driving LED behind the voltage of the small resistor of current detection circuit detection LED series connection, feeds back to single-chip microcomputer and adjusts the PWM dutycycle.