# Spannungsteiler

Der **Spannungsteiler** ist eine Vorrichtung aus meist gleichartigen elektronischen passiven Bauteilen, die eine eingehende Spannung um einen bestimmten Pegel absenkt.

For DC voltages as construction units electrical of resistances are used, with alternating voltages are possible a realization by means of resistances , condensers , transformers and coils.

The structure of standardR 2 consists of a series connection* of two*_{ resistances} R *1*_{ and}.

The input voltage *U*_{ e} is applied to the total circuit, the output voltage *U*_{ A} only at one of the resistances, in the fig. *R*_{ 2} is measured. Then applies to the unloaded voltage divider (for this specialExample)* the voltage divider formula*:

- <math>

U_a = U_e \ cdot \ frac {R_2} {R_1+R_2} </math>

Somewhat more generally calm the voltage divider rule the following means: In a series connection the voltage drops are proportional to the resistances, at which they drop.

When simple example, if *R*_{ is } 1 *=*_{ R} 2, applies then:

- <math>

U_a = \ frac {U_e} {2} </math>

Every other relationship between 0 and 1 is also possible.

With an adjustable resistance (potentiometer) the pick-up for U *A*_{ can } be shifted on a continuous resistance body, D. h. the division ratio is then variable.