№2 – pracrical work

№ 2 – PRACRICAL WORK

THEME: CALCULATION OF SINGLE-PHASE ALTERNATING CURRENT ELECTRICAL CIRCUITS
Training purpose.

Types of concepts and chemists about alternating current acquaintance with the active, reactive and tula capacities of the chain, learning to construct vector diagrams based on the calculated values.

A current whose values and direction change over time is called alternating current. The technique uses currents that change according to sine law. The values and direction of the Sinusoidal alternating current are repeated at the same time intervals called the period.

2.1-pic Sinusoidal EYUK chart

1. 
   The time of one complete oscillation of alternating current is called the period (T).
   
2. 
   The number of periods in one second is called frequency (f).
   
3. 
   The value of alternating current at an arbitrary moment, the value of instantaneous (i1), is called.
   
4. 
   The greatest value of alternating current over half a period is called its amplitude or maximum value.
   

1
f  Герц
Т

( Гц )

2.1-exercise. The frequency of alternating current used in aircraft is 200 Gs.
Determine the period.

Solution:
1
Т  
f
1
200


 0 .005


сек .

2.2-exercise. The bulging frequency of alternating current ω=3140 SEC-1. Determine the frequency and period of the same current.

Solve :

  2f ( Гц )


f  
2 
3140
2  3 .14

 500 Гц

1
Т  
f
1
500


 0 .002


сек .

The following main consumers are present in the AC circuit:

Consumers with active resistance note that with Voltage in such consumers, the current changes the same.

Consumers with reactive resistance, the resistance of such consumers depends on the frequency of the current, as they say

L
inductive resistance
Х   L
Om.

capacity resistance
1

с
Х 
  С
Om.

Full chain resistance Z  ^Om.