When the amplitude of the input signal is kept unchanged, the frequency is changed so that the output signal is reduced to 0.707 times the maximum value, that is, the frequency response characteristic is expressed as the cutoff frequency at the -3dB point, which is a special frequency used to describe the frequency characteristic index. The cutoff frequency is related to the cathode material, and the v0 of different metal materials is generally different.
When light strikes a metal surface, electrons escape from it. But not every frequency of incident light can cause the photoelectric effect. For a certain metal material, only when the frequency of the incident light is greater than a certain frequency v0, electrons can escape from the metal surface and form a photocurrent. This frequency v0 is called the cutoff frequency, also known as the red limit frequency, the limit frequency. The cutoff frequency is related to the cathode material, and the v0 of different metal materials is generally different. If the frequency v of the incident light is less than the cutoff frequency v0, then no matter how strong the incident light is, the photoelectric effect cannot be produced.
Upper limit f1 and lower limit f2 cut-off frequency bandpass filters
The cut-off frequency refers to the boundary frequency at which the output signal energy of a system begins to decrease significantly or rise significantly in a band-stop filter (generally -3dB as the limit).
cut-off frequency
The cut-off frequency is a measure used to describe the frequency characteristics of a filter or an amplifier.
A filter or an amplifier, while keeping the amplitude of the input signal unchanged, changes the signal frequency so that the output signal drops to 0.707 times the maximum value (corresponding to -3dB), or 0.5 times (corresponding to -6dB), the frequency is called the cutoff frequency.
cut-off voltage
The cut-off voltage, also known as the charging cut-off voltage, refers to the voltage when the battery reaches the fully charged state during the specified constant current charging period.
If it continues to charge after reaching the termination voltage, it is overcharging, which is generally harmful to battery performance and life.
The light current is measured by changing the incident light frequency. The minimum frequency of the light with the light current is the cutoff frequency. After the photocurrent appears, the directional voltage is applied so that the minimum voltage where the photocurrent is equal to zero is the cut-off voltage.