In a simple first-order RC low-pass filter, the filter time constant is how to understand, what is the role in practice? It and filter out of square wave narrow pulse have what relation?

How shall we understand the figure of this passage? Whether or not related to time constant

CodePudding user response:

A voltage applied to an RC series circuit circuit, capacitor voltage change Vc=U (1 - e ^ (-t/RC)) , when t=3 RC, Vc=0.9502 U, that is, any a RC system, charging RC time, 3 C is 95% of the charging voltage, the voltage can be thought of electricity is fully charged, so the RC can be used as a measure of how fast charging, which is the nature of time constant

CodePudding user response:

reference 1/f, worldy response:

a voltage applied to an RC series circuit circuit, capacitor voltage change Vc=U (1 - e ^ (-t/RC)) , when t=3 RC, Vc=0.9502 U, that is, any a RC system, charging RC time, 3 C is 95% of the charging voltage, the voltage can be thought of electricity is fully charged, so the RC can be used as a measure of how fast charging, which is the nature of time constant meaning

Thank you for your answer, the RC time as a filter, can you explain square wave filter out of the narrow pulse or narrow pulse in the RC circuit can filter out square wave,

CodePudding user response:

refer to the second floor flamesP response:

Quote: refer to 1st floor worldy response:

A voltage applied to an RC series circuit circuit, capacitor voltage change Vc=U (1 - e ^ (-t/RC)) , when t=3 RC, Vc=0.9502 U, that is, any a RC system, charging RC time, 3 C is 95% of the charging voltage, the voltage can be thought of electricity is fully charged, so the RC can be used as a measure of how fast charging, which is the nature of time constant meaning

Thank you for your answer, the RC time as a filter, can you explain square wave filter out of the narrow pulse or narrow pulse in the RC circuit can filter out square wave,

What is a narrow what is wide?

CodePudding user response:

refer to the second floor flamesP response:

Quote: refer to 1st floor worldy response:

A voltage applied to an RC series circuit circuit, capacitor voltage change Vc=U (1 - e ^ (-t/RC)) , when t=3 RC, Vc=0.9502 U, that is, any a RC system, charging RC time, 3 C is 95% of the charging voltage, the voltage can be thought of electricity is fully charged, so the RC can be used as a measure of how fast charging, which is the nature of time constant meaning

Thank you for your answer, the RC time as a filter, can you explain square wave filter out of the narrow pulse or narrow pulse in the RC circuit can filter out square wave,

Can, you can imagine, and 3 rc time filled with electricity, if its duration is level with low frequency pulse is greater than 3 rc, low level of time also is more than 3 rc, so high electrical capacitance charging can be full of at ordinary times, low electric discharge at ordinary times, can light, C on the voltage and input voltage are basically the same, as the frequency increases, the duration of the high level or low level is less than 3 rc, or high and low level time is less than 3 rc, voltage will be around a level fluctuation sawtooth wave, that is to say, the high frequency component was significantly suppressed