ACADs (08-006) Covered Keywords

1. Electronic Controls ACADs (08-006) Covered Keywords Switching power supply, amplifier, logic, digital, circuit, solid state. Description Supporting Material

2. PVNGS GOALS

4. Plant Status Class Guidelines PVNGS Goals Focus on Five Lab PPE requirements Student Participation Attendance sheet Breaks Introduction

5. Course Terminal Objective Using reference material furnished by the instructor, the Plant Technician will discuss solid state fundamentals, build, calibrate and test electronic circuits to support theory, and demonstrate an understanding of solid state fundamentals by successful completion of a Lab Practical Evaluation (LPE).

6. Enabling Objectives 1.1.1 Describe the HU fundamentals to be used and hazards associated with working on electronic components. 1.1.2 Describe the purpose for Inspecting and reworking printed circuit boards. 1.1.3 Describe the functions and associated controls of the Tektronix 2445 Oscilloscope. 1.1.4 Describe barrier potential effects on the PN junction of a general purpose diode. 1.1.5 Build/test/analyze a series and series-parallel diode circuit. 1.1.6 Describe special purpose diode design and application. 1.1.7 Build/test/analyze a Zener diode voltage regulator circuit. 1.1.8 Describe Single Phase DC power supply design and application.

7. 1.1.9 Build/test/analyze a Single Phase DC Power supply circuit. 1.1.10 Describe voltage divider and voltage multiplier device design and application. 1.1.11 Describe Light Emitting Diodes (LED's) device design and application. 1.1.12 Build/test/analyze an LED circuit. 1.1.13 Describe Bipolar Junction Transistor (BJT) device design, operation and application. 1.1.14 Build/test/analyze a Bipolar Junction Transistor (BJT) switching circuit. 1.1.15 Describe Silicon Controlled Rectifier (SCR) device design and application. 1.1.16 Build/test/analyze an SCR switching circuit. 1.1.17 Describe Triac, Diac, and Unijunction Transistor (UJT) device design and application. 1.1.18 Build/test/analyze a Triac, Diac, and UJT circuit.

8. 1.1.19 Describe Field Effect Transistor (FET) device design and application. 1.1.20 Build/test/analyze a Field Effect Transistor (FET) circuit. 1.1.21 Describe Integrated Circuit (Op Amp) device design and application. 1.1.22 Build/test/analyze integrated (Op Amp) circuits. 1.1.23 Describe Digital Logic symbols and truth tables. 1.1.24 Describe Fiber Optic circuit device design and application.

9. Prevent Events Prevent Events Achieving Breakthrough Performance It’s everyone’s responsibility to work safely and prevent events. Ask yourself before beginning a job: NEA07

10. Prevent Events Prevent Events What are the critical steps of the task? What document describes it? Do I understand it? NEA07

11. Prevent Events Prevent Events What is the worst thing that can happen and how can I prevent it? NEA07

12. Prevent Events Prevent Events What else could go wrong? NEA07

13. Prevent Events Prevent Events What are the safety and/or radiation protection considerations? NEA07

14. Prevent Events Prevent Events Is my training, and are my qualifications up to date? NEA07

15. Class Experience

16. INVERTER AC OUTPUT BREAKER TRIP CIRCUIT DRAWING E054-00164 NEA07

17. E054-00163 NEA07

18. Backplane Drawing E054-00162 NEA07

19. PC Board HU and Safety Electrostatic discharge: • Electrostatic discharge is the movement of electrons from a source to an object. • Static electricity is an electrical charge at rest. • The most common way to build static electricity is by friction. • Friction creates an electron buildup or a negative static charge. • When a person contacts a positive charged or grounded object, all excess electrons flow (jump) to that object. • Electrostatic discharge can be 35,000 volts or more. • People normally do not feel electrostatic discharges until the discharge reaches 3000 volts. • Solid state devices and circuits may be damaged or destroyed by a 10 volt electrostatic discharge. The effects of static discharge may be cumulative and not readily obvious. • Technicians and maintenance Electricians should wear a wrist grounding strap or other type of grounding device to avoid damage to solid state devices and circuits. NEA07

20. U2R9: 2EPNDN14 INVERTER BACKPLANE COLD SOLDER CONNECTIONS ON XFMR. Cold Solder Joint NEA07

21. U2R9: 2EPNDN14 INVERTER BACKPLANE COLD SOLDER CONNECTIONS ON XFMR. Cold Solder Joint NEA07

22. U2R9: 2EPNDN14 INVERTER BACKPLANE COLD/DIRTY SOLDER CONNECTIONS ON BACKPLANE Cold Solder Joint NEA07

23. U2R9: 2EPNDN14 INVERTER BACKPLANE COLD/DIRTY SOLDER CONNECTIONS ON BACKPLANE Cold Solder Joint NEA07

24. U2R9: 2EPNDN14 INVERTER BACKPLANE COLD/DIRTY SOLDER CONNECTIONS ON BACKPLANE Cold Solder Joint NEA07

25. Cold Solder Joint U2R9: 2EPNDN14 INVERTER BACKPLANE COLD SOLDER CONNECTIONS ON XFMR. N NEA07

26. U1R9: 1EPKDN44 INVERTER BACKPLANE NEA07

27. U1R9: INVERTER 1EPKDN44 BACKPLANE NEA07

28. U1R9: INVERTER 1EPKDN44 J2 BOARD FOIL SIDE DAMAGED PC BOARD + 15 VOLT PIN CONTACT. NEA07

29. U1R9: INVERTER 1EPKDN44 J2 BOARD FOIL SIDE DAMAGED PC BOARD + 15 VOLT PIN CONTACT. U1R9 NEA07

30. U1R9: 1EPNAN11 INVERTER: MISSING MOLEX CONNECTOR PIN U1R9 NEA07

31. U1R9: 1EPNAN11 INVERTER: MISSING MOLEX CONNECTOR PIN. U1R9: INVERTER 1EPNAN11: DOOR CONTROL PANEL: DEFECTIVE MOLEX CONNECTOR PIN. U1R9 NEA07

32. Tektronix 2445 • Section 3 – Controls, Connectors and Indicators

33. Review of semiconductor fundamentals 1. In Semiconductors production, doping refers to the process of intentionally introducing impurities into an extremely pure (intrinsic) semiconductor in order to change its electrical properties. 2. Basic semiconductor materials are silicon and germanium. In there pure state they are poor conductors and have 4 Electrons in the valence shell, by adding impurities to the intrinsic structure we create an excess of holes or electrons in the material. 3. Boron, arsenic, phosphorus and occasionally gallium are used To dope silicon and are called dopants.

34. Silicon and germanium have 4 electrons in the outer shell.

35. Silicon doped with a trivalent material such as boron becomes known P-type. The trivalent material has 3 electrons leaving the outer valenceDeficient 1 electron or “hole”. The majority current carriers are holes.

36. Silicon doped with a pentavalent material such as phosphorus becomes known as N-type. The pentavalent material has 5 electrons .living the outer valence shell 1 free electron. Electrons are the majority Current carrier.

37. PN Junction formation: Combine them to make one piece of semiconductor which is doped differently on each side of the junction.

38. Free electrons on the n-side and free holes on the p-side can initially wander across the junction. When a free electron meets a free hole it can 'drop into it'. So far as charge movements are concerned this means the hole and electron cancel each other and vanish. As a result, the free electrons and holes near the junction tend to eat each other, producing a region depleted of any moving charges. This creates what is called the depletion zone.

39. P N Junction BiasingApplying a forward or reverse bias to the junction will change the depletion region width .Forward bias reduces the region resulting in conductionReverse bias enlarges the region resulting in no conduction.

40. Junction Diode The Junction diode is the simplest semiconductor. It is formed by doping on-half of the intrinsic material with a p-type dopant and the other half with an n-type dopant. The boundary at the p and n regions is called the pn junction.

41. Typical junction drop Silicon-- 0.7volts, Germanium --0.3volts Junction Diode Characteristic

42. Junction Diode Parameters • When selecting diodes, two device ratings must be taken into consideration; Peak Reverse Voltage and Maximum Average Forward Current Can be classified as: • Maximum Average Forward Current is usually given at a special temperature, usually 25°C, (77°F) and refers to the maximum amount of average current that can be permitted to flow in the forward direction. If this rating is exceeded, structure breakdown can occur. • Peak Reverse Voltage or Peak Inverse Voltage is the maximum voltage that a diode can withstand in the reverse direction without breaking down and starting to conduct. If this voltage is exceeded the diode may be destroyed. Diodes must have a Peak Inverse Voltage rating that is higher than the maximum voltage that will be applied to them when reverse biased.

43. Zener Diodes A Zener diode is a type of diode that permits current to flow in the forward direction like a normal diode, but also in the reverse direction if the voltage is larger (not equal to, but larger) than the rated breakdown voltage known as "Zener knee voltage" or "Zener voltage". The breakdown voltage can be controlled quite accurately in the doping process. Tolerances to within 0.05% are available though the most widely used tolerances are 5% and 10%.

44. Zener Diodes The zener diode uses a p-n junction in reverse-bias to make use of the zener-effect, which is a breakdown phenomenon which holds the voltage close to a constant value called the zener “knee” voltage. It is useful in regulator applications

45. Various Diodes and there symbols. Diode symbols: a - regulating and HF diode, b - LED, c, d -Zener, e - photo, f,g - tunnel, h - Schottky, i - breakdown, j - capacitative

46. NEA07 Page 45 Slide 15

47. NEA07

48. NEA07 Slide 18

49. NEA07 Slide 17

50. Transistors • Can be classified as: • BJT – Bipolar Junction Transistor; • Minority carrier device; • Bipolar device. • FET – Field Effect Transistor; • Majority carrier device; • Unipolar device;