06-07-21 DIODE

Diode:- Diode limits the current, It means that it allows electric current to go only in one direction.

It is a polarised component with two leads, called the Anode(+) & the Cathode(-). The cathode is normally marked with a Silver or colour band.

Potential Barrier:- 

1) 0.7 volts for Silicon

2) 0.3 volts for Germanium

Types of Diode:- 

1) Zener diode

2) P-N junction diode

3) Tunnel diode

4) Photo diode

5) Laser diode

6) LED 

7) PIN diode.

Uses of Diode:- Diode can be used as Rectifiers, Signal limiters, Voltage Regulators, Switches, Signal Modulators, Oscillators.

The fundamental property of a diode is its tendancy to conduct electric current in only one direction.

Diode

03-07-21 Power Factor

Power Factor (P.F):- The cosine of angle between voltage & current is called power factor.

Formula of P.F:-

P=V×I CosӨ

CosӨ=P/V.I  OR KW/KVA

Where,

P=Power in Watts

V=Voltage in Volts

I=Current in Amperes

CosӨ=Power Factor

W=Real power in Watts

VA=Apparent power in Volts-Amperes OR KVA

Types of Power Factor:-

1) Unity Power Factor

2) Lagging Power Factor

3) Leading Power Factor

Types of Electrical Load:-

 

1) Resistivity load (Unity P.F):

➡ Press, heater, incandescent bulb, water heater etc are the examples of resistivity load.

2) Inductive load (Lagging P.F):

➡ Drilling machine, table fan, water pump are the examples of inductive load.

P.F of motor in inductive load will 0.8.

3) Capacitive load (Leading P.F):

➡There is no capacitive load, usually we use capacitor for capacitive load.

Method for Improving Power Factor:-

➡APFC Panel (Maintain Near Unity P.F)

APFC→Automatic Power Factor Correction Panel

Power Factor Scale

Note:- Power Factor is only in AC & not in DC because there is no Frequency in DC.