Project - Analysis of a practical automotive wiring circuit

Ans 1) Major elemets in the above diagram is as follows -

Battery, Generator, Starter, Current & Voltage regulator, Fuse, Distributor, Breaker, Ignition coil, Ignition switch, Ammeter.

Ans 2) Purpose & working of elements as bellow -

Battery - It is the power house of the system, battery provides the required voltage & current to the components connected in circuit. Battery are of 2 types rechargable & non-rechargable the one we are using in the circuit is rechargable type as it will get discharged while supplying power & need to be re-charged to continue its working. A battery is a electro-chemical device that stores electrical charge in form of chemical reaction, it consists of anode, cathode, electrolyte which are responsible for converting electrical energy into chemical reaction & vice versa. Battery stores the electrical charge & is capable of charging & discharging in order to provide power supply to the system through out its working cycle.

Generator - It is a device that generates electricity by converting the mechanical energy (i.e. shaft rotation) into electric energy that can be utilised to power the circuit. It is similar to a electric motor only the working is opposite. A simple generator consists of a rotor on which permanent magnet is attached on the rotating shaft & the cover (stator) consists of core with windings. As the rotor (magnet) is rotated the changing magnetic field generates electricity in windings which is than transfered to voltage converter & regulator to convert into usable form. Generator charges the battery in engine running condition & also provide electrical power to the circuitary.

Voltage & Current Regulator - It is a set of power electonics used to convert AC current produced by generator to regulated DC voltage required to charge the battery & power the electronic components in the circuit. A regulator consists of rectifier which converts the AC voltage produced by generator into DC voltage, further this DC voltage is maintained on the rquired potential using voltage regulator to maintain steady output voltage. This output regulated voltage is than supplied to battery & connected circuitry for consumption.

Ans 3) Fuse is a safety device which we connect in series with the load to safeguard the battery & load from current spike generated due to short circuit or any other malfunctioning in circuit. A fuse is selected such that it permits the maximum current required for the load simultaneously protecting it from high current surges. Thus in case of our circuit considering full load of 10 Ampere a fuse rated with 15 Ampere should be used, as it is the standard value of available fuse such that it can prevent the circuit from current spike/surge generated due to short circuit or any system electical failure.

Ans 4) If the battery load is 500 Watt, considering battery voltage as 12 Volts which is ideally used in our automobiles. The capacity of the battery should be such that it can power the circuit for atleast an hour i.e.

500 Watts for 1 hour = 500Whr,

As battery voltage is 12V so the current draw will be, I = P/V = 500/12 = 41.66 Ah

Considering the nearby standard value the battery capacity should be atleast 50Ah with a voltage of 12V.

Ans 5) Components that are connected parallel to each other are -

(a) Instrument lamps - 3 nos. of instrument lamps are connected in parallel to each other in above circuit. All the 3 lamps are connected in parallel so that the voltage available to the lamp is same for all 3 thus the brightness will be same. Parallel connection help us to simultaneously turn ON / OFF the lamps using a single switch.

(b) Horn - both side horns are connected in parallel to each other so that we can operate them simultaneously leading to an increased sound intensity when operated. Parallel connection help us to simultaneously turn ON / OFF both horns using a single switch.

Ans 6) Components that are connected in series to each other are -

(a) Battery & ammeter are connected in series so that ammeter can check the current flow from the battery to the circuit & current flow from generator to battery. As the current flow in a circuit is same for components connected in series the current flow from & to the battery can be monitored.

(b) Ignition switch is connected in series with ignition coil so that ignition coil can be turned ON / OFF as per requirement by changing the position of ignition switch.