Electricity/Direct current

Direct currentEdit

Direct current is a current that flows in one direction. The value of the current can change over time. However, the direction does not change over time. The polarity of the current remains the same at every point in time. A direct current can be provided by a voltage source.

 

An ideal voltage source is a source of electricity that provides a constant voltage independent of the current that is drawn from the source. The polarity of the voltage source does not change over time. A voltage source is a theoretical device. A real voltage source can deliver a constant voltage when the current that is delivered to a load is within certain boundaries. e.g. a voltage source 24 V / 0-3 A can keep the voltage at 24 V when the delivered current is in between 0 to 3 A.

 

SymbolEdit

o---[- +]---o

DC and conductorEdit

ResistorEdit

Voltage by Ohm's law

 

Current

 

Resistance

 

Conductance

 

Power generated

 

Power loss . Power is dissipated as heat

 
 
 

Power transmitted

 

CapacitorEdit

Charge

 

Capacitance

 

Voltage

 

Current

 

Power

 

Electric field

 

InductorEdit

Magnetic field intensity

 

Inductance

 

Current