1. Optocuploare Amplificatoare-Izolatoare Aplicaţii

2. Transformer Ground Isolation

3. Optocoupler Block Schematic

4. Tuning transmitter / receiver wavelengths

5. Texas Instruments first optocoupler

6. Analog optocouplers

7. Phototransistor / Photo-Darlington Optocouplers

8. Optocouplers using other photo-detectors in the output circuit : a. a photo-FET, b. a Light-Activated SCR ( Silicon Controlled Rectifier), and c. a Light-Activated -Triac

9. The Schottky Transistor

10. Typical digital optocoupler ( first manufactured by Hewlett-Packard )

11. Interfacing two logic circuits through optocouplers provides ground isolation

12. Dual Analog Optocoupler

13. Free-space light barrier to detect obstacles

14. Confocal lens system increases detection resolution

15. Position transducer or /and tachometer using an optocoupler

16. Reflection Optocoupler

17. Checking the leaking current i.e. the isolation resistance

18. Path of the common mode in an optocoupler

19. Measuring the common mode rejection

20. Neutralizing parasitic capacitance

21. Neutralizing both common-mode capacitances in a dual link

22. Optocoupler’s CTR − Current Transfer Ratio

23. Measuring the D.C. CTR (statically )

24. Phototransistor turned into a controlled current generator to accurately determine CTR

25. Dark Current Measurement Circuit

26. Current vs. Voltage Characteristic of the Optocoupler Input LED

27. Determining the saturation voltage of the output phototransistor

28. Optocoupler Switching Mode Operation

29. Recommended circuit for measuring the optocoupler switching times

30. Optocoupler Transfer Characteristic in Frequency Domain

31. Optocoupler Pass-band Determination

32. Experimental result

33. Desensitivation of the Optocoupler Phototransistor

34. Faster Response

35. Using a cascode also speeds-up the circuit

36. Faster Turn-On by Using the Classical Peaking Capacitor in the Base-Circuit of the LED Driver

37. The Effect of the Peaking Capacitor on the Forward Current

38. Shortening the Switching Times by Prebiasing the LED

39. Practical Circuit for LED Pre-bias

40. Strong peaking

41. Typical Digital Optocoupler

42. Large Miller Capacitance of the Output Phototransistor Can Change the Output Characteristics

43. Replacing the Phototransistor with a PD + Regular BJT Combination Corrects the Previous Behavior

44. Open-Circuit on behalf of the not-connected transistor hurts ( it is better to short its legs)

45. Like That !

46. Draining the charge out of the junction shortens optocoupler turn off

47. Coupling the discharge circuits is detrimental

48. Isolation Amplifiers

49. Ground Isolation Means Infinite Impedance Between the Meant Circuits

50. Isolation Amplifier Circuit Symbol

51. Controlled-Gain Amplifier Provides Optically-Isolated Control Circuit

52. Same function, different circuit

53. Basic Isolation Amplifier with Negative Feedback in the Receiver

54. Feedback Parallel-Series Topology Turns the Photodiode into a Current Generator

55. Feedback circuit loading effect upon the basic amplifier

56. Equivalent Schematic of the Feedback Amplifier Showing the Loading Effects

57. Compensating for optocoupler non-linearity by using a matching-device in the feedback loop

58. Nonlinearity compensation through negative feedback in the transmitter

59. LEDs ‘True’ Control

60. Classical Compensated Isolation Amplifier

61. Differential Isolation Amplifier

62. Switch-Mode Amplifier

63. FM Modulation Used for Linear Signal Transfer Over a Light Barrier

64. PWM − Pulse-Width Modulation over Light Barrier

65. Principle of PWM

66. Manufacturer’s Recommended Circuit to Experimentally Obtain the Transfer Characteristic in the Frequency Domain

67. Isolation-Amplifier Transfer Characteristic

68. Different Configuration – Same Transfer Characteristic Envisaged

69. Isolation-Amplifier Gain vs. Frequency Characteristic, as Given in Data Sheet

70. Din capitolul Fotodioda, urmatoarele două aplicaţii pot fi considerate amplificatoare izolatoare cu optocuploare

71. Densimeter

72. Intrusion Detector