Signal one-waytransmission, the input and output of the full realization of electricallyisolated output signal has no effect on the input side, anti-interferenceability, stable, non-contact, long life,and high transmission efficiency.Optical Coupler is the production of new devices developed in the1970s, is now widely used in electrical insulation, level conversion,inter-stage coupling, drive circuit, switching circuit, chopper, multivibrator signalisolation, isolation level, pulseamplifier circuit, digital instrumentation,the long-distance signal transmission, pulse amplification, solid state relay(SSR), instrumentation, communications equipment, and computer interface.Chipswitching power supply, linear optocoupler constitute optocouplerfeedback circuit by adjusting the control end of the current to change the dutycycle, the purpose of precision voltage regulator.

Typeof Optocoupler

The correct choice of model and parameters ofthe optocoupler Optocoupler optical isolation circuit must be designed,selected the following principles:

1,Optical Coupler for the one-way signal transmissiondevices, and data transmission circuit is a the bidirectional circuit boardcertain size requirements, combined with the actual requirements of the circuit design,it is necessary to select a single chip integrated multi-channel optocouplerdevices;

2,Optocoupler current transfer ratio (CTR), theallowable range is not less than 500%. The optocoupler LED operating current(> 5.0 mA) because when the CTR <500%, in order to ensure that the signaldoes not occur in the long-term transmission error, this will increase thepower consumption of the optocoupler;

3,The Optical Coupler transmission speed is one ofthe selectOptical Coupler must follow the principle of optocoupler switching speedis too slow, can not make the correct response to the input level will affectthe normal operation of the circuit.

4,Recommend the use of a linear optocoupler. Whichis characterized by the CTR values ??can be adjusted within a certain range dolinear. The design of the circuit input and output is a high-low level signal,and therefore, the circuit operates in a nonlinear state.Online applications,because the signal is undistorted transmission should be in accordance with therequirements of the dynamic work setting appropriate quiescent operating pointof the circuit operating in the linear state