Electronics

Electronics af Nadeeshika Wickramarachchige Dona

1. Circuit Elements : 1) Passive ( Resistors, Capacitors , Inductors) 2) Active (DC/AC power source , Battery , Transistors & Photodiodes.

2. Ohm's Law , V= IR, For parallel resistors , Req = R1R2/ (R1+R2) & Foe series of resistors , Req = R1 +R2.

3. Basic concepts of Electronics

4. Charge (Q), Unit = Coulomb (C) {Charge of e} = - {Charge of proton}

5. Current (i), Units =C/s or A Equation = dQ/dt

6. Voltage (Potential Energy) : Works needs to separate charges. Units :1 J/C = 1V

7. Kirchoff's Law : 1) Current Law & 2) Voltage Law

8. Voltmeter & Loading errors

9. Capacitor's capacitance (C), Unit = Farad / F , Q= CV

10. Charging & Discharging time when both Capacitor and resistor combined a circuit. Unit of RC /Time constant = Seconds (s)

11. AC (Alternating current ) For resistors

12. AC for capacitors

13. Reactance (Resistance for capacitors)

14. Impedance (Z)

15. Digital Electronics

16. Analog Data : continuous data

17. Digital Data : Discrete data

18. Convert binary to decimal 1001 = 1*2^3 + 0* 2^2 + 0* 2^1 + 1*2^0 =8+0+0+1 =9

19. Convert Decimal to binary Ex: 25 = 25-16 -> 9, 9-8-> 1 Thus, 11001

20. Digital/Analog Data transforms : 1) ADC ( Analog to Digital Converter) & 2) DAC (Digital to Analog Converter)

21. DAC

22. ADC

23. Acquisition (Digitization of Values) : Smallest voltage increment = Range / 2* (# of bits) , Different levels of voltage = 2^n (# Number of bits)

24. Nyquist Criterion , f sample > or = 2 f signal

25. 3) Instrumental Noise (1/f noise)

26. 3. Current Follower

27. Operational Amplifiers & Digital Circuits

28. Critical Connections for OP-AMP ; 1. Inverting input (-), 2. Non-inverting input (+) & 3. Output

29. Input Voltages : V+ & V-

30. Input difference (bias) / Vs = V+ - V-

31. Power supply = +PS & -PS

32. Open loop gain = A

33. Output voltage / V0 = A( V+ - V-)

34. Impedance (Z) = Zi & Zo

35. Types of Op Amp 1.Comparator , Vo = A (V+ - V- ) = A Vi

36. 2. Voltage Follower , Vo = Vi + V s , For finite Vo, Vs > 0, therefore Vo=Vi

37. 4.Inverting Voltage Amplifier / Scaler

38. 5. Adder , eo= -[e1(Rf/R1) + e2(Rf/R2) + e3(Rf/R3)]

39. 6. Difference Amplifier

40. 7. Multiplication & Division Amplifiers

41. 8. Integration Amplifiers

42. 9.Differentiator

43. 10.Logarithmic Amplifier

44. Signal & Noise

45. Signal : Instrumental response ( Measured from the baseline to the top of the peak)

46. Noise

47. Signal (S)/ Noise (N) = mean/ Standard Deviation = 1/RSD

48. Types of noises , 1) Thermal Noise

49. 2) Shot Noise

50. Noise reduction methods, 1. Grounding/Shielding 2.Filtering 3. Ensemble average 4. Boxcar averaging 5. Moving averaging