jännitehaarukan

Jännitehaarukka, often translated as voltage divider, is a simple passive linear circuit that produces an output voltage (Vout) that is a fraction of its input voltage (Vin). It is constructed using two impedance elements in series, typically resistors, across which the input voltage is applied. The output voltage is taken across one of the impedance elements.

The fundamental principle behind a jännitehaarukka is Ohm's Law and Kirchhoff's Voltage Law. When resistors are used, the voltage drop across each resistor is proportional to its resistance. If two resistors, R1 and R2, are connected in series across an input voltage Vin, the current flowing through them is I = Vin / (R1 + R2). The output voltage, taken across R2, is then Vout = I * R2 = (Vin / (R1 + R2)) * R2. This can be simplified to Vout = Vin * (R2 / (R1 + R2)). This formula clearly shows that Vout is a fraction of Vin, determined by the ratio of R2 to the total resistance.

Jännitehaarukat have numerous applications in electronics. They are commonly used to reduce a high voltage to a lower, more manageable level for sensitive components. They can also serve as a reference voltage source, a means of impedance matching, or in sensor circuits to convert a physical quantity like temperature or light into a corresponding voltage change. While simple resistor dividers are most common, other impedance elements like capacitors and inductors can also be used, leading to frequency-dependent voltage division. Care must be taken when designing a jännitehaarukka, especially regarding the load connected to the output, as it can affect the division ratio.