0
Upcoming SlideShare
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Standard text messaging rates apply

# Leacture 8 electrical systems

399

Published on

1 Like
Statistics
Notes
• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

Views
Total Views
399
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
26
0
Likes
1
Embeds 0
No embeds

No notes for slide

### Transcript

• 1. Electrical Systems Conductors good electrical conductors. Copper, Steel, Gold and Silver Insulators poor electrical conductors. Plastic, Rubber and Glass • Traditionally current flow form +ve to -ve • Electron flow theory (Ohms Law) electrons flow from –ve to +ve • Magnetic field is developed when current passes through a wire.
• 2. Electrical Systems Voltage is a measurement of the pressure that causes the electrical energy(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 Systems Current current flow is created when voltage moves electrons through a conductor. • This flow is measured in amperes and the symbol is A • Must 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 Ohms • Symbol R or Ω Resistance 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 Resistance Current (I) = Voltage divided by Resistance Resistance = 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. Reasons • • • • Burned fuse Light bulbs Broken wires Defective switch
• 8. Electrical Systems Grounded Circuit • Copper to Iron • Damage to insulated wires. • Short to Ground • Short Circuit causes excess current flow.
• 9. Electrical Systems Excessive 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 electrical current in one direction. • Current flows from +ve to -ve
• 11. ELECTRICAL CIRCUTS • Current flows from +ve to -ve • Voltage is also known as electrical pressure. • Each circuit should have a • Power 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 flow through 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 Protection Fuses (Protect the circuit from shorts)
• 16. Fuses Circuit Protection
• 17. Wiring Type Primary Wire is small and carries battery or alternator voltage. • Colour coded • Wiring size is measured in GAUGE • The thinner the wire, the higher the gauge number • 18 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 Repair Computer 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.
• 21. Electrical Systems Credits • Google search engine (Images)