Data Sheet

-84-
156. Cutoff Frequency of 10kW Resistor and
100mF Capacitor RC Circuit
Build the circuit shown on the left and turn on the switch (62). Press the
press switch (61) and you will see the bi-directional LED (71) light red.
Release the press switch (61) and the bi-directional LED (71) will stay
bright for a while and then turn dim. If the 10kW resistor (44) and 100mF
capacitor (73) in this project were used in an RC low pass lter, then
the cutoff frequency would be 1/(2*3.14*10,000*100e
-6
) = 0.16 Hz.
Only very low frequencies (near DC) would pass through such a circuit.
157. Cutoff Frequency of 100kW Resistor and
100mF Capacitor RC Circuit
Replace the 10kW resistor (44) in project #154 with the 100kW resistor
(45) and then turn on the switch (62). Press the press switch (61) and
you will see the bi-directional LED (71) light red. Release the press
switch (61) and the bi-directional LED (71) will stay bright for many
seconds before turning dim. If the 100kW resistor (45) and 100mF
capacitor (73) in this project were used in an RC low pass lter, then the
cutoff frequency would be 1/(2*3.14*100,000*100e
-6
) = 0.016 Hz.
Only very low frequencies (near DC) would pass through such a circuit.