Ylipäästöjännittely

Ylipäästöjännittely, also known as a high-pass voltage divider, is an electronic circuit designed to selectively allow higher frequencies to pass through while attenuating or blocking lower frequencies. It is a fundamental concept in analog circuit design and finds applications in various signal processing tasks.

The circuit is typically constructed using a resistor and a capacitor, or a resistor and an inductor. In a simple RC high-pass filter, the capacitor is placed in series with the input signal, and the output is taken across the resistor, which is connected to ground. At low frequencies, the capacitor acts as an open circuit, blocking the signal from reaching the output. As the frequency increases, the capacitor's impedance decreases, allowing more of the signal to pass to the output.

The cutoff frequency, denoted as fc, is a crucial parameter for a high-pass voltage divider. This is the frequency at which the output voltage is reduced to approximately 70.7% (or -3 dB) of the input voltage. For an RC circuit, fc is calculated as 1 / (2 * pi * R * C), where R is the resistance and C is the capacitance. An RL high-pass filter uses a resistor in series with an inductor, with the output taken across the resistor. Its cutoff frequency is calculated as R / (2 * pi * L), where L is the inductance.

High-pass voltage dividers are used in audio circuits to remove low-frequency hum or rumble, in signal conditioning to isolate AC signals from DC offsets, and as building blocks for more complex filters like band-pass and band-stop filters. Their simplicity and effectiveness make them a staple in electronics.