Circuit Fundamentals: Voltage, Current Dividers, and Power Calculations

Power Divider

A current divider is a configuration present in electrical circuits that can fragment the power of a source of different impedances connected in parallel.

Suppose we have a current source I _C, connected in parallel with n impedances. The negative polarity of the source I _C - should be connected to the reference node. Impedances must close the circuit.

The dual circuit current is the divider voltage divider .

Current divider equations

For a current divider with n impedances, we have a scheme like this:

Electric power

Electrical power is the ratio of step energy per unit time, ie the amount of energy delivered or absorbed by an element in a certain time (p = dW / dt). The unit in the International System of Units is the watt or watt, which is the same.

When an electric current flows in a circuit, can transfer energy to make a mechanical work or thermodynamically. The devices convert electrical energy in many useful ways, such as heat , light ( incandescent lamp ), motion ( electric motor ), Sound ( speaker ) or chemical processes . The electricity can be produced mechanically or chemically by the generation of electricity , or also by the transformation of light into the photoelectric cell . Finally, it can be stored chemically in batteries .

DC power

When it comesdirect current (DC) electrical power evolved over time by a two-terminal device is the product of potential difference between the terminals and the current intensity passing through the device. For this reason the power is proportional to the current and voltage. That is,

( 1 )

Conversion Delta-Star and Star-Delta - (Δ conversion - Υ and Υ - Δ)

In order to simplify the analysis of a circuit is sometimes desirable to display all or part of a circuit in a different way, but without the overall functioning of this change.

Some circuits have a group of r esistance which are arranged to form a triangle and others like a star.

There is a simple way to convert this resistance from one format to another and vice versa. It is not just a matter of changing the position of resistance if not get the new values ​​that they will have.

Delta Star Configuration Settings

The formulas used are as follows:

Voltage divider

A voltage divider is a circuit configuration that delivers the power of a source from one or more impedances connected in series .

Suppose we have a voltage source V _f, n connected in series with impedance.

For the voltage at the generic impedance Z _i, using the Ohm's law :

Substituting the second equation into the first we find that the voltage at the generic impedance Z _i is:

Note that when calculating the voltage drop across each impedance and closed loop is traversed, the result is zero, thus respecting the second law of Kirchhoff .

An analog circuit voltage divider in the current domain iscurrent divider.