Basics of Electrical Engineering

PROJECT OBJECTIVE

This project is intended to give the basics of electrical engineering and electronics by highlighting the basics in electronics and using programming to try to solidify these principles.

REQUIRED KNOWLEDGE

• Understanding of programming. preferably python.
• Understanding of basic mathematics.

ELECTRONICS BASICS

CHARGE

Unit of charge is the coulomb. Coulomb is the quantity of electricity flowing past a given point.

`1 coloumb=1Amp * 1 second=As=6.24*10^(18)` electrons

one coulomb is 1 amp * 1-second =Amp second

The quantity of charge = current in amperes* time in seconds=Q

`Q=1A*1*s=1 c`

`Q=A*t`

Quantity of charge units are coulombs

WORK

The unit of work or energy is the joule(J). 1 J is 1 Nm

1 J is transferred when a force of 1 Newton is exerted through a distance of 1 m in the direction of the force.

Mechanically:

`W=F*s=m*a` where:

• W=Work done in J (joules)
• F=Force in Newton
• s=Distance in M (metres)
• m=mass in Kg
• a= acceleration in metres per second squared

In electricity, work is equal to power multiplied by time.

`W=P*t`

• P=is power in watts
• t=time in seconds
• W=P*t=J(joules)=watt second(Watts second)
• Units of work are J(joules) or Watt second(Watts second)

VOLTAGE

1 V is 1 Joule per coulomb.

1 V is the difference in potential between two points in a conductor which when carrying a current of one ampere dissipates a power of one watt.

`P=V*I`

`V=P/I=(W)/(Amp)=(J)/(s)*(1)/(I)`

`Q=It=C`

`I=C/t`

`V=J/s*(s/C)=J/C`

where:

P=power=W=Watts

V=Voltage

I=Current in ampres= amp

Q=Quantity of electric charge

C=coloumb

s=t=time in seconds

RESISTANCE

Resistance is the opposition of current flow and is given by the formulae below.

`R=V/I` Where :

R is the resistance in Ohms

V is the voltage or electric potential

I is the current in amperes

PYTHON PROGRAM

To calculate the missing value.

#python program for calculating electric charge

print('\n')
print('Q=Amps*time')
print('\n')
print('t is in seconds : s')
print('Current is in Amperes : Amps ')
print('Q is the quontity of charge in coloumbs: c')
print('Enter the following variables separate them by a coma\n')
print('The one you  want to calculate should be replaced by question mark')
print('dont put symbols or letters betwween the digits separated by colomn ')
print('use the formart specified below')
print('Quantity of electric charge,Current in Amperes,Time in seconds')
print('Q,A,t')


def validate_input_data(data):
    error='na'
    data=data.split(',')
    if len(data)>3: error='given input is too long'
    if len(data)<3: error='given input is too short'
    
    if error =='na':
       for i in data:
           if i=='?':
              error='na'
              break
           else:
              error='no question mark in the input' 
    return error

def calculate_missing_value(data):
    data=data.split(',')
    question_mark_position=23
    ans='eror in calculation'
    k=0
    for i in data:
        if i=='?':
           question_mark_position=k
        k=k+1   
           
    if question_mark_position==0:
        val=float(data[1])*float(data[2])
        ans= 'value of Q is = '+str(val)+' Columbs'
    if question_mark_position==1:
        val=float(data[0])/float(data[2])
        ans= 'value if A is ='+str(val)+' Amperes'
    if question_mark_position==2:
        val=float(data[0])/float(data[1])
        ans= 'Value of t is ='+str(val)+' Second'

    return ans



def main():
    print('hi')
    while 1==1:
         input_values=input()
         if validate_input_data(input_values) !='na':
            print(validate_input_data(input_values))
            print('try again')
         else:
            print('\n')
            print(calculate_missing_value(input_values))
            print('\n')

main()            

Conclusion

The above program can be easily modified to use other formulae as shown above to calculate energy ,power, resistance. etc.

REF

Theraja : Circuit Theory

John Bird: Circuit Theory