jännitteenjakajassa

A jännitteenjakaja, or voltage divider in English, is a simple passive linear circuit that produces an output voltage (Vout) that is a fraction of its input voltage (Vin). It is typically constructed from two or more resistors connected in series across a voltage source. The output voltage is taken across one of the resistors.

The most basic form of a voltage divider consists of two resistors, R1 and R2, connected in series. The input voltage Vin is applied across the series combination of R1 and R2. The output voltage Vout is measured across R2. The relationship between Vin, Vout, R1, and R2 is given by the voltage divider formula: Vout = Vin * (R2 / (R1 + R2)). This formula shows that the output voltage is directly proportional to the ratio of R2 to the total resistance (R1 + R2).

Voltage dividers are widely used in electronics for various purposes. They can be used to reduce a higher voltage to a lower, usable voltage. For example, a voltage divider can be used to power a low-voltage component from a higher-voltage supply. They are also employed to create reference voltages, to attenuate signals, and as a means of reading sensors like potentiometers or thermistors, where the resistance of the sensor changes the output voltage.

While simple and effective, voltage dividers have limitations. They are not efficient for power delivery, as power is dissipated in both resistors. The output voltage can also be affected by the load connected to it; if the load draws significant current, it effectively changes the resistance of R2, altering the output voltage. For applications requiring stable voltage under varying load conditions or efficient power transfer, more complex circuits like voltage regulators are preferred.