Project - Analysis of a practical automotive wiring circuit

Project - Analysis of a practical automotive wiring circuit.

1. The major elements in the above automotive wiring circuit are;

Battery, Starter, Ignition coil, Distributor, Breaker, Juntion Block, Generator, Current and Voltage regulator, Horn, Selector switch, Fuse, Ammeter, Dome light switch, Dome light, Gas tank, Tail stop etc.

2. Battery : The first purpose of an auto battery is to provide power for starting your vehicle. It also acts as a surge protector for the car's computer and provides power for short-term use of things like lights, stereo, GPS or wipers when the engine is off.

 A typical lead-acid car battery contains plates of lead alternating with plates made up of other materials, all immersed in an electrolyte solution of about one-third sulfuric acid and two-thirds water. Turning the ignition triggers the acid in the liquid electrolyte solution to react with the active material on the plates. This generates a bigger electrical current. The current travels through the starting system in a chain of reactions that causes the engine to start.

Junction Block : Automotive junction box (automotive electrical central controller) integrates the whole car's fuse, circuit breaker, relay and so on. It is the vehicle electronic circuit control center. A junction block, or terminal block, provides a convenient point for all wiring in a vehicle. This central location helps provide electrical power to various systems in a tidy manner. Terminal blocks prevent shorts, eliminate wire splicing and also conserve panel space.

Fuse : Automotive fuses are a class of fuses used to protect the wiring and electrical equipment for vehicles. They are generally rated for circuits no higher than 32 volts direct current, but some types are rated for 42-volt electrical systems. They are occasionally used in non-automotive electrical products. Automotive fuses are typically housed inside one or more fuse boxes within the vehicle, typically on one side of the engine compartment and/or under the dash near the steering wheel. 

There may be a fuse for ignition off draw (IOD), which controls the drawing of electric current in a vehicle while it is shut off; removing this fuse while the vehicle is shut off for more than a few weeks will prevent excessive depletion of the battery.

Ammeter : Ammeter is a device used to measure either alternating or direct current. We know that ampere is the unit of current. Since this device measures the value in amperes, it’s known as ammeter.

3. The fuse rating should be 125 % to 130 % of the load on the current. Here the supplied current is 10A so the rfuse rating should be 12.5 to 13 .

4. For 500W load the battery voltage given is 12V and the current can be obtained as 500Wh/12V = 41.66Ah

5. The elements connected in parellel are Horn, Dome light, Brake etc. They are connected in parellel to get the same voltage supply.

6. The elements connected in series are horn switch, horn buttton, fuse, dome light, dome switch, brake light, tail stop etc. They are connected in series to get equal current supply.