- IDEAL DIODE:-
Fig(a) Symbol of Diode |
⇒An ideal diode is behaves same as an Ideal switch.
- Behaviour of an Ideal Switch:
➝" An ideal switch is defined as a device which doesn't consume any power from the supply source".
➝When switch is open then current trough the switch Isw = 0 amp. Because source is isolated from the load RL.
- At that time voltage across the sitch sw (Vsw) is ..............
- Applying KVL........
-Vs + Vsw + VL = 0 .............(1)
But, switch SW is open so current Isw=IL = 0
VL = IL × RL
∴ VL = 0 × RL
VL = 0 volt ................(2)
Put VL= 0 in Equation Number (1).......
-Vs + Vsw + 0 = 0
∴ Vs = Vsw ..............(3)
- Power loss across the switch SW during switch SW is open is (P1).........
= 0 × Vsw
P1 = 0 watt.
CASE:-2 When Switch SW is closed
➝ When Switch SW is closed then the voltage across it Vsw = 0, because of short circuit. But the current Isw= IL ≠ 0.
- Power loss across the switch SW during switch SW is closed is (P2)..........
P2 = IL × Vsw
= IL × 0
P2 = 0 watt.
So, from above discussion we conclude that an Ideal switch SW doesn't consume any power from the source.
- I-V characteristics of an Ideal Diode:
➝ During positive half cycle of ac supply ,When Switch SW is closed at that time Vsw=0 and I >0 so the Characteristic is straight line (vertical) passing through origin as shown in I-V characteristics.
➝During the negative half cycle of ac supply, when switch SW is open at that time Vsw>0 and I= 0 so the Characteristic is straight line (Horizontal) passing through the origin as shown in I-V characteristics.
➝In above both cases R= 0 because it is an Ideal Diode.
....................Thank you 🙂..................
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