Jänniteerottelu

Jänniteerottelu, often translated as voltage division, is a fundamental concept in electrical engineering describing how voltage is distributed across components in a series circuit. When resistors are connected in series, the total voltage applied across the combination is divided among them in proportion to their resistances. This means that a larger resistance will drop a proportionally larger share of the total voltage.

The principle can be understood using Ohm's Law, which states that voltage (V) equals current (I) multiplied by resistance (R). In a series circuit, the current is the same through all components. Therefore, if you have two resistors, R1 and R2, in series with a total voltage V_total, the voltage across R1 (V1) is given by V1 = I * R1 and the voltage across R2 (V2) is V2 = I * R2. Since I = V_total / (R1 + R2), substituting this into the voltage equations gives V1 = V_total * (R1 / (R1 + R2)) and V2 = V_total * (R2 / (R1 + R2)). This formula is known as the voltage divider rule.

Voltage dividers are widely used in electronics to create a lower voltage from a higher voltage source. They are essential for providing specific voltage levels required by different components in a circuit, such as for biasing transistors or creating reference voltages. While simple to implement, voltage dividers have limitations, particularly in their inability to supply significant current without the output voltage dropping considerably due to the internal resistance of the source and the load.