AC Supply | Single phase AC Supply | Application

AC Supply :

The ac supply can be of two types : Single phase ac supply Three phase ac supply
1. Single Phase AC Supply :
2. Three Phase AC supply

Single Phase AC Supply

~ The electric supply used for the domestic applications is single phase ac supply whereas that used for the factories, institutions ete. is a three phase ac supply.
~ The single phase ac supply is a two wire system.
~ The twoi wires involved are called "Phase" and "Neutral" as shown in Fig. 1.7.1
~ The voltage between phase and neutral points is sinusoidal with an rms value of 230 V and a frequency of 50 Hz.
~ The neutral point has approximately the same potential as that i of the earth point. It is treated as the reference point.
~All the home appliances such as lamps, tubelights, fans, TV refrigerator, heaters etc. are connected in parallel across the single phase ac supply as shown in Fig. 1.7.2.

Three Phase AC Supply :
~ The electnc supply used for the high power domestic and industrial applications is a three phase ac supply.
~ This supply can be a 3 wire system or a 4 wire system. Thei three phases are marked as R, Y, B and the fourth wire is the neutral (N) wire.
~ The voltage measured between any two phases is called asi the line voltage. Typically its value is 415 V.
~ The frequency of the ac voltage at the output of the threei phase ac supply is 50 Hz.

Battery as DC Supply :
For many applications we need to use a low voltage dci source. The "batterv' is used as DC power supply for such applications.
The batteries can be of different types such as : 1. Lead acid batteries. 2. Nickel cadmium batteries. Dry batteries. 4. Maintenance free batteries.
One has to make use of an appropriate battery depending on the application.
For cars, two wheelers and other vehicles the lead acid batteries are preferred.
Fig. 1.8. 1(a) shows the symbol of a battery. We can connect batteries in series as shown in Fig. 1.8. 1(b). So as to increasei the terminal voltage whereas they can be connected in parallel so as to increase the current sourcing capacity (Seei Fig. 1.8.1(c)).

Applications :

1. Torch.
2. Radio, music system, laptop computers. 3. Cars, two wheelers and other vehicles.
4. UPS systems.