How do you tell the difference between RC, RL, LC circuits?
Each of these circuits, and what they qualitatively do in DC and AC circuits...
RC - a resistor and capacitor in series. Exhibits charging behaviour with characterisitic time constant with DC voltage source. Acts as a high pass filter (allows high frequency currents, but not low frequency currents) in AC circuits.
RL - a resistor and inductor in series. Acts as a short with a DC voltage source, but smooths out rapid variations in current. Acts as a low pass filter (allows low frequency currents, but not high frequency currents) in AC circuits.
LC (and RLC) - an inductor and capacitor (and resistor) in series. If initially charged, has oscillitory behaviour (damped if also has a resistor). Has resonant behaviour with AC driving voltage (damped if also has a resistor).
1 comment:
Just came across this randomly, but I wanted to note that for an RC circuit, it can be a low pass filter as well depending on what you are looking at. For example, if you look at the output across the cap with one end of the cap to ground, then in this case it's a low pass.
What you are assuming is the voltage is taken across the resistor with the resistor directly connected to ground. In this case, it is a high pass filter.
Just wanted to clear this up for anyone coming across this in the future.
Post a Comment