Presentation on theme: "Basic Electrical Systems Theory and Repair"— Presentation transcript:
1 Basic Electrical Systems Theory and Repair Chapter 29Page 387
2 So, Where is Electronics in a Car EverywhereAntilock brakes, engines, emissions, dash, fuels system, transmissions, tires, suspension, windows, safety systems, lighting.----Well, I could go on and on and on.
6 Conductors Conductors A good conductor must not have more than four electrons in the outer valence ring of an atom. Copper is one of the best conductors; along with aluminum and gold, conductors have one electron in the outer valence ring.
7 Insulators Insulators A good insulator must have more than four electrons in the outer valence ring of an atom. Rubber, glass, and porcelain are the best insulators with many electrons in the outer valence ring.
9 Electron Movement This is the way it really is! Negative to PositiveThis is what we are taught!Positive to Negative
10 Wiring is coated with PVC, a flexible plastic to insulate the copper wiring. Color Chart
11 Circuit Requirements = A full circle is provided Switch12 vComplete pathLoad(light)+Source(Battery)_Source – Battery or voltage supplyLoad – Electrical components, lights, radio, etc.Complete path for electron flow – Wires and connections
12 Circuit Devices Controls Devices Protection Devices Switches for on and offFuses and Circuit BreakersProtect form Overloads
15 Electrical TermsVoltage- Also called Electromotive Force, Pressure of electricity or the amount of force it takes to move electrons. Measured in volts.Current- The movement or flow of electrons, measured in amperes or amps for short.Resistance-Anything that impedes or slows the flow of electrons. Measured in ohms.
16 More Electrical TermsAC – Alternating Current (shop lights and equipment)DC – Direct Current (Auto battery and most systems)Auto voltage used is normally between 12 and 15 volts
32 A Few More TermsSemiconductors- Can act as both insulator and conductor.Diode- an electronic one way check valve, it allows flow one way but doesn’t allow it to reverse the other way.Transistor- electronic relay. Its very fast, and no moving parts.
33 Basic Tests Meters Analog and Digital Digital Volt-ohm Meter (DVOM) or Digital Multimeter (DMM)
41 Diode CheckDiode is a one way street only. Reversing the multimeter leads will tell us if the voltage is allows one way and is stopped the opposite way. If it doesn’t do this toss the diode..000 one way and 1. the other.
42 Testing Device with Ohmmeter with Power Removed Continuity Should be .000 if GoodInfinity Should be 1. if Bad
43 Testing AmpsNeed to change red probe lead to Amp on meter
48 Circuit DefectsOpenIncomplete or broken circuit. The circuits quits working.ShortTwo wires unintentionally connecting with each other. Could cause more than one component to operate.
49 Circuit Defects Ground When a positive and negative wire contact each other. Could cause sparking and extreme heat due to high current flow. Very low resistance blows fuses, circuit breakers, or fusible links.
53 Your Job.Complete chapter Questions 1-15 (review) and 1-10 (ASE-style). PageWrite on a separate paper and write out the complete question and your answer. ( do not write the other answer options).Complete the chapter worksheet (I will give it out). You may write on it.File all items in your note book.Notebooks will be graded in the future.