Data Sheet

-85-
158. Cutoff Frequency of 1kW Resistor and
470mF 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 blue.
Release the press switch (61) and the bi-directional LED (71) will stay bright
for a little while and then turn dim. If the 1kW resistor (42) and 470mF
capacitor (74) in this project were used in an RC low pass lter, then the
cutoff frequency would be 1/(2*3.14*1,000*470
e
-6
) = 0.34 Hz. Only very
low frequencies (near DC) would pass through such a circuit.
159. Cutoff Frequency of 5.1kW Resistor and
470mF Capacitor RC Circuit
Replace the 1kW resistor (42) in project #158 with the 5.1kW resistor (43)
and turn on the switch (62). Press the press switch (61) and you will see the
bi-directional LED (71) light blue. Release the press switch (61) and the bi-
directional LED (71) will stay bright for a while and then turn dim. If the 5.1kW
resistor (43) and 470mF capacitor (74) in this project were used in an RC low
pass lter, then the cutoff frequency would be 1/(2*3.14*5,100*470e
-6
) =
0.066 Hz. Only very low frequencies (near DC) would pass through such a circuit.
160. Cutoff Frequency of 10kW Resistor and
470mF Capacitor RC Circuit
Replace the 1kW resistor (42) in project #158 with the 10kW resistor (44) and
then turn on the switch (62). Press the press switch (61) and you will see the bi-
directional LED (71) light blue. Release the press switch (61) and the bi-directional
LED (71) will stay bright for several seconds and then turn dim. If the 10kW
resistor (44) and 470mF capacitor (74) in this project were used in an RC low
pass lter, then the cutoff frequency would be 1/(2*3.14*10,000*470e
-6
) =
0.034 Hz. Only very low frequencies (near DC) would pass through such a circuit.
161. Cutoff Frequency of 100kW Resistor and
470mF Capacitor RC Circuit
Replace the 1kW resistor (42) in project #158 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 blue. Release the press switch (61) and the bi-directional
LED (71) will stay bright for a long time and then turn dim. If the 100kW resistor
(45) and 470mF capacitor (74) in this project were used in an RC low pass lter,
then the cutoff frequency would be 1/(2*3.14*100,000*470e
-6
) = 0.0034 Hz.
Only very low frequencies (near DC) would pass through such a circuit.