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What is the folding frequency?
(Also called Nyquist frequency.) The highest frequency that can be measured using discretely sampled data. It is given by nf (rad s-1) = π/Δt, where nf is the Nyquist frequency and t is the time increment between observations.
What is the significance of folding frequency?
In signal processing, the Nyquist frequency (or folding frequency), named after Harry Nyquist, is a characteristic of a sampler, which converts a continuous function or signal into a discrete sequence. In units of cycles per second (Hz), its value is one-half of the sampling rate (samples per second).
How is the frequency of a radio signal measured?
Many signals are a mixture of different frequencies and different strengths. Frequency is measured in Hertz (Hz), meaning 1 cycle per second. The radio spectrum is broken into groups, with names such as HF (high frequency), VHF (very high frequency), and UHF (ultra-high frequency).
How are high frequency signals transmitted between substations?
High frequency signals are transmitted between substations A and B as shown in Fig. 10.28. These signals are arranged to be sent in bursts only during the positive half cycles of the power frequency current.
How are high frequency signals arranged in detection circuits?
The high frequency signals generated at each end of the line will now, when combined, form a continuous signal. The detection circuits are arranged such that under reception of such a continuous signal tripping is inhibited. 3.8.2.1 Case I-Spectral Broadening Due to the Signal Modulation is Larger than that of the Laser.
How are power frequency fault currents displaced at substations?
The power frequency fault currents at substations A and B will therefore be displaced by approximately 180°. The high frequency signals generated at each end of the line will now, when combined, form a continuous signal. The detection circuits are arranged such that under reception of such a continuous signal tripping is inhibited.