A kind of controlling light illuminating apparatus of sewing machine
Technical field:
The invention belongs to sewing machine technique field, refer in particular to the controlling light illuminating apparatus of a kind of sewing machine.
Background technology:
Conventional sewing machine lamp circuit is directly connected to power supply by a current-limiting resistance and LED, with the on and off of a controlling switch lamp.So, the brightness of lamp is fixed, and the electric energy of consumption is constant, it is impossible to regulate, it is impossible to adapt to different light environments, and can the vision of operator be impacted.
Summary of the invention:
It is an object of the invention to provide a kind of suitable in varying environment, easy to use, protect the controlling light illuminating apparatus of the vision of user novel sewing machine energy-conservation again.
The present invention is achieved in that
A kind of controlling light illuminating apparatus of sewing machine, it is electrically connected with testing circuit between main control chip power supply and main control chip and the light sensor of control signal is provided, light sensor is connected between main control chip positive source and negative pole, and it is connected to main control chip by testing circuit, the pulsewidth modulation outfan of main control chip electrically connects with isolation optocoupler, the pulse control signal of isolation optocoupler output controls the brightness of the illuminating lamp with independent illumination power supply, concrete structure is: the emitter stage of isolation optocoupler output electrically connects and electrically connect mains lighting supply negative pole with the emitter stage of the audion Q1 of peripheral hardware, the colelctor electrode of isolation optocoupler simultaneously with the base stage of audion Q1, main control chip positive source electrical connection after series resistance R2, mains lighting supply positive pole is sequentially connected in series resistance R1, electrically connect with the colelctor electrode of audion Q1 after illuminating lamp.
Above-mentioned testing circuit is the resistance R4 and electric capacity C1 that are connected in parallel, resistance R4 and one end after electric capacity C1 parallel connection and the negative pole of main control chip power supply and the ADI pin of main control chip electrically connects, the other end electrically connects with the SGND end of main control chip.
Above-mentioned audion is NPN audion.
Above-mentioned illuminating lamp is more than one LED.
The voltage of above-mentioned mains lighting supply is 5-12V.
Above-mentioned light sensor is photoconductive resistance or phototriode or photocell.
One end of above-mentioned light sensor is connected with the positive electrical of main control chip power supply, the other end electrically connects with the ADI pin of main control chip.
The advantage that the present invention highlights compared to existing technology is:
1, the present invention detects the light of environment by light sensor (photoconductive resistance), the illumination power of environment is different, cause photoconductive resistance change in resistance, therefore by the change of resistance R4 voltage in testing circuit, main control chip just it is estimated that the now illumination of environment is strong and weak, thus controlling the brightness of LED, adapts to ambient light, light sensor has measurement wide ranges, easy to use, cheap, long transmission distance, is easily installed on various sewing machines, it is adaptable to various places.
2, the present invention is automatically adjusted the brightness of LED, protects the vision of user, has saved again energy.
Accompanying drawing illustrates:
Fig. 1 is circuit diagram of the present invention.
Detailed description of the invention:
With specific embodiment, the invention will be further described below, referring to Fig. 1:
A kind of controlling light illuminating apparatus of sewing machine, it is electrically connected with testing circuit 2 between main control chip power supply 1 and main control chip U1 and the light sensor of control signal is provided, light sensor is connected between main control chip U1 positive source and negative pole, and it is connected to main control chip U1 by testing circuit 2, the pulsewidth modulation outfan PWM of main control chip U1 electrically connects with isolation optocoupler U2, and the pulse control signal of isolation optocoupler U2 output controls the brightness of the illuminating lamp 3 with independent illumination power supply VC.
The control signal of above-mentioned isolation optocoupler U2 output controls with the brightness of the illuminating lamp 3 of independent illumination power supply VC: the emitter stage of isolation optocoupler U2 output electrically connects with the emitter stage of the audion Q1 of peripheral hardware and electrically connect mains lighting supply negative pole, the colelctor electrode of isolation optocoupler U2 is connected with main control chip power supply 1 positive electrical after the base stage of audion Q1, series resistance R2 simultaneously, and mains lighting supply VC positive pole electrically connects with the colelctor electrode of audion Q1 after being sequentially connected in series resistance R1, illuminating lamp 3.
Above-mentioned testing circuit 2 is the resistance R4 and electric capacity C1 that are connected in parallel, resistance R4 and one end after electric capacity C1 parallel connection and the negative pole of main control chip power supply 1 and the ADI pin of main control chip U1 electrically connects, the other end electrically connects with the SGND end of main control chip U1.
Above-mentioned audion Q1 is NPN audion.
Above-mentioned illuminating lamp 3 is more than one LED.
The voltage of above-mentioned mains lighting supply VC is 5-12V.
Above-mentioned light sensor is photoconductive resistance R5 or phototriode or photocell.
One end of above-mentioned light sensor is connected with the positive electrical of main control chip power supply 1, the other end electrically connects with the ADI pin of main control chip U1.
The operation principle of the present invention is:
When ambient light increases, photoconductive resistance R5 resistance diminishes, and the voltage now entering into master control new film UI pin ADL increases.Main control chip U1 is through computing, and from the PWM duty cycle signal that the output of PWM pin is less, (the low electricity frequency of PWM is effectively), thus reducing the output brightness of LED.
The PWM pin of main control chip U1 is pulsewidth modulation outfan, controls opening and shutoff of audion Q1, thus controlling the brightness of sewing machine LED.When PWM pin output duty cycle changes, it is possible to regulate the brightness of LED.Isolation optocoupler U2 serves the effect of isolation, main control chip U1 power supply and LED isolated from power, it is to avoid interfere with each other.
Above-described embodiment is only one of presently preferred embodiments of the present invention, not limits the practical range of the present invention with this, therefore: the equivalence change that all shapes under this invention, structure, principle are done, all should be covered by within protection scope of the present invention.