Jännitejakon

Jännitejakon is a Finnish term that translates to "voltage divider" in English. It refers to a passive linear circuit that produces an output voltage (Vout) that is a fraction of its input voltage (Vin). A basic voltage divider consists of two resistors connected in series across a voltage source. The output voltage is taken across one of these resistors.

The fundamental principle of a voltage divider relies on Ohm's Law. When two resistors, R1 and R2, are connected in series to a voltage source Vin, the current flowing through the circuit is determined by the total resistance (R1 + R2). The voltage drop across each resistor is then proportional to its resistance. If the output voltage is taken across R2, the formula for the voltage divider is Vout = Vin * (R2 / (R1 + R2)). This equation shows that the output voltage is directly proportional to the ratio of R2 to the total resistance.

Voltage dividers are widely used in electronics for various purposes. They are employed to reduce a high voltage to a lower, usable voltage for sensitive components, to create reference voltages, or as part of sensor circuits where a change in resistance (e.g., from a thermistor or photodiode) directly affects the output voltage. While simple and effective, voltage dividers have limitations. They are not efficient for delivering significant power, as power is dissipated in both resistors. Also, the output voltage can be affected by the load connected to it, as the load resistance appears in parallel with R2, altering the division ratio.