Presentation on theme: "Electrical Systems Conductors good electrical conductors."— Presentation transcript:
1 Electrical Systems Conductors good electrical conductors. Copper, Steel, Gold and SilverInsulators poor electrical conductors.Plastic, Rubber and GlassTraditionally current flow form +ve to -veElectron flow theory (Ohms Law) electrons flow from –ve to +veMagnetic field is developed when current passes through a wire.
2 Electrical SystemsVoltage is a measurement of the pressure that causes the electricalenergy(Current) to flow.Same as water through pipe.No movement unless force or pressure is applied.Is measure in volts (V) and the symbol is E
3 Electrical SystemsCurrent current flow is created when voltage moves electronsthrough a conductor.This flow is measured in amperes and the symbol is AMust be a complete circuit before the current can flow.DC Direct Current flow (Automotive)AC Alternating Current it changes its direction of flow (House)
4 Electrical Systems Resistance is opposition to current flow. Amount is measured in OhmsSymbol R or ΩResistance of a conductor depends on:Type of material.Size or material (Wire Gauge)Length of the conductor.Temperature of the conductor (Lower the temperature,less the resistance)
5 Electrical Systems OHMS Law E = Voltage I = Current R = Resistance Voltage (E) = Current (I) X ResistanceCurrent (I) = Voltage divided by ResistanceResistance = Voltage divided by Current (I)
6 Electrical Systems Circuit Testers Test Light DVOM (Digital Voltage, Ohmmeter, Ammeter)
7 Electrical Systems Open Circuit When the electrical path is broken. Stops current flow and prevents operation of device.ReasonsBurned fuseLight bulbsBroken wiresDefective switch
8 Electrical Systems Grounded Circuit Copper to Iron Damage to insulated wires.Short to GroundShort Circuit causes excess current flow.
9 Electrical SystemsExcessive Resistance is the most common problem on vehicles.Lose or dirty connections.Undersized wires or cables.Broken strands of wire.Excessive heat buildups.Burned switch contacts.Excessively long wires.
10 Electrical Systems Diode Is a solid state electronic device that, allows the passage of an electricalcurrent in one direction.Current flows from +ve to -ve
11 ELECTRICAL CIRCUTS Current flows from +ve to -ve Voltage is also known aselectrical pressure.Each circuit should have aPower source (Battery)Circuit protection device (Fuse)Switch (open/close)Load (bulb, horn, etc.)Conductor (wires)
12 ELECTRICAL CIRCUTS SERIES CIRCUIT Power source and loads are in series.If the path is broken, no current flows. (Christmas lights)Voltage is divided between the loads.Current flow is same throughout the circuit.The resistance of each load can be different.
13 ELECTRICAL CIRCUTS PARALLEL CIRCUIT More then one path for current flow.In the event of an open in one branch, current will continue to flowthrough the remaining.Each branch receives source voltage.Current flow and resistance of each branch could be different.
14 ELECTRICAL CIRCUTS AUTOMOTIVE ELECTRICAL CIRCUITS(One wire circuit) Negative battery cable is attached to the car frame.Negative from each load is connected to the car frame.Vehicle’s body or frame acts as a conductor (wire)
15 Circuit ProtectionFuses (Protect the circuit from shorts)
17 Wiring Type Primary Wire is small and carries battery or alternator voltage.Colour codedWiring size is measured in GAUGEThe thinner the wire, the higher thegauge number18 gauge is thinner then 12 gauge.
18 Wiring Repair Crimp connectors and terminals Quick repair of automotive wiring.Crimping pliers are used for connectors.
19 Wiring RepairComputer control wires must be soldered for good connection,and heat shrunk.
20 Wiring Jumper Wire is used to by-pass circuits. If the component works after by-passing, the component is faulty.