Project - Analysis of a practical automotive wiring circuit

1,The major elements in the above automotive wiring diagram are starter ,battery, breaker, generator, ammeter, fuse, switches, distributer, horn, gas tank unit

2, fuse - the purpose of fuse is to safeguard the circuit or the appliance connected to it and the working is to limit the current in an electric circuit which melts and breaks the circuit whenever there is an excess flow of current through the circuit.

battery - the purpose of battery is to supply the energy to the circuit and battery is a device that stores chemical energy and converts it to electrical energy. The chemical reactions in a battery involve the flow of electrons from one material to another, through an external circuit. The flow of electrons provides an electric current that can be used to do work.

breaker - the purpose of breaker is to protect the circuit and equipments at abnormal conditions such as short circuit and the working of the breaker is to make and break the circuit under faulty conditions of current. 

3, If the total load is 10A from battery then the fuse should be 10*125% = 12.5A but the next higher standard size is 15A,so we choose 15A as fuse rating.

4,If 500W is the load then I would recommend a battery with a voltage of 12V and a capacity of at least 20Ah.

5, distributer and generator are connected parallel to each other to get constant voltage.

6, fuse and ammeter are connected in series because in there current should go same .