Are these two circuits the same?
Are these rwo circuits the same considering the right hand sides of them where it is parallel for the C&R and C&L(meaning the way i should obtain the frequency response?
And for the longer circuit how do i obtain the frequency response and the freqency for MAX amplitude response(im lost with the second one)
band-pass
asked 13 hours ago
abdullah ifthiquar
111
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abdullah ifthiquar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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add a comment |
Are these rwo circuits the same considering the right hand sides of them where it is parallel for the C&R and C&L(meaning the way i should obtain the frequency response?
And for the longer circuit how do i obtain the frequency response and the freqency for MAX amplitude response(im lost with the second one)
band-pass
asked 13 hours ago
abdullah ifthiquar
111
New contributor
abdullah ifthiquar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
2
The second one passes DC. The first one does not. Therefore they are not the same.
– Transistor
13 hours ago
may be similar but never the same, at high f, C1/(C1+C2) dominates
– Tony EE rocketscientist
13 hours ago
3
@Transistor no. The second one doesn’t pass DC. It short-circuits it to ground.
– Edgar Brown
11 hours ago
1
OK. I had assumed a real inductor. Thanks.
– Transistor
11 hours ago
add a comment |
Are these rwo circuits the same considering the right hand sides of them where it is parallel for the C&R and C&L(meaning the way i should obtain the frequency response?
And for the longer circuit how do i obtain the frequency response and the freqency for MAX amplitude response(im lost with the second one)
band-pass
asked 13 hours ago
abdullah ifthiquar
111
New contributor
abdullah ifthiquar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Are these rwo circuits the same considering the right hand sides of them where it is parallel for the C&R and C&L(meaning the way i should obtain the frequency response?
And for the longer circuit how do i obtain the frequency response and the freqency for MAX amplitude response(im lost with the second one)
band-pass
band-pass
asked 13 hours ago
abdullah ifthiquar
111
New contributor
abdullah ifthiquar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 13 hours ago
abdullah ifthiquar
111
New contributor
abdullah ifthiquar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 13 hours ago
abdullah ifthiquar
111
New contributor
abdullah ifthiquar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 13 hours ago
abdullah ifthiquar
111
asked 13 hours ago
abdullah ifthiquar
111
111
New contributor
abdullah ifthiquar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
abdullah ifthiquar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
abdullah ifthiquar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
2
The second one passes DC. The first one does not. Therefore they are not the same.
– Transistor
13 hours ago
may be similar but never the same, at high f, C1/(C1+C2) dominates
– Tony EE rocketscientist
13 hours ago
3
@Transistor no. The second one doesn’t pass DC. It short-circuits it to ground.
– Edgar Brown
11 hours ago
1
OK. I had assumed a real inductor. Thanks.
– Transistor
11 hours ago
add a comment |
2
The second one passes DC. The first one does not. Therefore they are not the same.
– Transistor
13 hours ago
may be similar but never the same, at high f, C1/(C1+C2) dominates
– Tony EE rocketscientist
13 hours ago
3
@Transistor no. The second one doesn’t pass DC. It short-circuits it to ground.
– Edgar Brown
11 hours ago
1
OK. I had assumed a real inductor. Thanks.
– Transistor
11 hours ago
2
2
The second one passes DC. The first one does not. Therefore they are not the same.
– Transistor
13 hours ago
The second one passes DC. The first one does not. Therefore they are not the same.
– Transistor
13 hours ago
may be similar but never the same, at high f, C1/(C1+C2) dominates
– Tony EE rocketscientist
13 hours ago
may be similar but never the same, at high f, C1/(C1+C2) dominates
– Tony EE rocketscientist
13 hours ago
3
3
@Transistor no. The second one doesn’t pass DC. It short-circuits it to ground.
– Edgar Brown
11 hours ago
@Transistor no. The second one doesn’t pass DC. It short-circuits it to ground.
– Edgar Brown
11 hours ago
1
1
OK. I had assumed a real inductor. Thanks.
– Transistor
11 hours ago
OK. I had assumed a real inductor. Thanks.
– Transistor
11 hours ago
add a comment |
1 Answer
1
active
oldest
votes
These two circuits can provide similar bandpass frequency response.
However, the lower-frequency cutoff must be considerably lower than the high-frequency cutoff. This means that the frequency span of the pass-band must be wide, if these two circuits are to provide similar results. For bandpass response with narrow pass-band, the LC circuit is king. Note that the RC bandpass cannot provide anywhere near as much output power as the LC bandpass - it must see a very high-impedance load.
Here's an example to illustrate similar bandpass response of the two circuits (both these examples deliver no power to a load):
If you know the corner frequency of the low-pass edge, and you know the corner frequency of the high-pass edge, I think the centre frequency of maximum response would be the geometric mean: $ sqrt{f_{lower} f_{upper}} $
For the RC circuit, upper corner frequency is near $ 1 over {2 pi R_1 C_2} $ while lower corner frequency is near $ 1 over {2 pi R_2C_1} $
Edit:
To get identical response I've added a loading resistor to the LC version (R5:9.091K), and I've added a different loading resistor to the RC version (R4:200K). The value of R2 was changed from 100k previously to 200k, to preserve the lower corner frequency). Now frequency response is identical:
answered 11 hours ago
glen_geek
8,8931916
You might provide a description of input and output impedances at DC -- where the circuits behave strikingly different.
– Scott Seidman
10 hours ago
@ScottSeidman Both LC & RC filters have similar response at low frequencies: they both drop at 20 dB/decade (no matter how you load them). Response of both at DC is infinite attenuation. Load resistances tend to affect the corner frequencies & mid-band attenuation.
– glen_geek
9 hours ago
"The same" is what the OP asked. Circuit one has an (ideal) infinite input impedance at DC, and Circuit 2 has an input impedance of R at DC. If nothing else, this can certainly impact your choice for R. Practically, you'd also want to know how you'll be driving each circuit. Not saying you're wrong, or off, but just giving you the opportunity to highlight the differences.
– Scott Seidman
9 hours ago
add a comment |
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1 Answer
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These two circuits can provide similar bandpass frequency response.
However, the lower-frequency cutoff must be considerably lower than the high-frequency cutoff. This means that the frequency span of the pass-band must be wide, if these two circuits are to provide similar results. For bandpass response with narrow pass-band, the LC circuit is king. Note that the RC bandpass cannot provide anywhere near as much output power as the LC bandpass - it must see a very high-impedance load.
Here's an example to illustrate similar bandpass response of the two circuits (both these examples deliver no power to a load):
If you know the corner frequency of the low-pass edge, and you know the corner frequency of the high-pass edge, I think the centre frequency of maximum response would be the geometric mean: $ sqrt{f_{lower} f_{upper}} $
For the RC circuit, upper corner frequency is near $ 1 over {2 pi R_1 C_2} $ while lower corner frequency is near $ 1 over {2 pi R_2C_1} $
Edit:
To get identical response I've added a loading resistor to the LC version (R5:9.091K), and I've added a different loading resistor to the RC version (R4:200K). The value of R2 was changed from 100k previously to 200k, to preserve the lower corner frequency). Now frequency response is identical:
answered 11 hours ago
glen_geek
8,8931916
You might provide a description of input and output impedances at DC -- where the circuits behave strikingly different.
– Scott Seidman
10 hours ago
@ScottSeidman Both LC & RC filters have similar response at low frequencies: they both drop at 20 dB/decade (no matter how you load them). Response of both at DC is infinite attenuation. Load resistances tend to affect the corner frequencies & mid-band attenuation.
– glen_geek
9 hours ago
"The same" is what the OP asked. Circuit one has an (ideal) infinite input impedance at DC, and Circuit 2 has an input impedance of R at DC. If nothing else, this can certainly impact your choice for R. Practically, you'd also want to know how you'll be driving each circuit. Not saying you're wrong, or off, but just giving you the opportunity to highlight the differences.
– Scott Seidman
9 hours ago
add a comment |
These two circuits can provide similar bandpass frequency response.
However, the lower-frequency cutoff must be considerably lower than the high-frequency cutoff. This means that the frequency span of the pass-band must be wide, if these two circuits are to provide similar results. For bandpass response with narrow pass-band, the LC circuit is king. Note that the RC bandpass cannot provide anywhere near as much output power as the LC bandpass - it must see a very high-impedance load.
Here's an example to illustrate similar bandpass response of the two circuits (both these examples deliver no power to a load):
If you know the corner frequency of the low-pass edge, and you know the corner frequency of the high-pass edge, I think the centre frequency of maximum response would be the geometric mean: $ sqrt{f_{lower} f_{upper}} $
For the RC circuit, upper corner frequency is near $ 1 over {2 pi R_1 C_2} $ while lower corner frequency is near $ 1 over {2 pi R_2C_1} $
Edit:
To get identical response I've added a loading resistor to the LC version (R5:9.091K), and I've added a different loading resistor to the RC version (R4:200K). The value of R2 was changed from 100k previously to 200k, to preserve the lower corner frequency). Now frequency response is identical:
answered 11 hours ago
glen_geek
8,8931916
You might provide a description of input and output impedances at DC -- where the circuits behave strikingly different.
– Scott Seidman
10 hours ago
@ScottSeidman Both LC & RC filters have similar response at low frequencies: they both drop at 20 dB/decade (no matter how you load them). Response of both at DC is infinite attenuation. Load resistances tend to affect the corner frequencies & mid-band attenuation.
– glen_geek
9 hours ago
"The same" is what the OP asked. Circuit one has an (ideal) infinite input impedance at DC, and Circuit 2 has an input impedance of R at DC. If nothing else, this can certainly impact your choice for R. Practically, you'd also want to know how you'll be driving each circuit. Not saying you're wrong, or off, but just giving you the opportunity to highlight the differences.
– Scott Seidman
9 hours ago
add a comment |
These two circuits can provide similar bandpass frequency response.
However, the lower-frequency cutoff must be considerably lower than the high-frequency cutoff. This means that the frequency span of the pass-band must be wide, if these two circuits are to provide similar results. For bandpass response with narrow pass-band, the LC circuit is king. Note that the RC bandpass cannot provide anywhere near as much output power as the LC bandpass - it must see a very high-impedance load.
Here's an example to illustrate similar bandpass response of the two circuits (both these examples deliver no power to a load):
If you know the corner frequency of the low-pass edge, and you know the corner frequency of the high-pass edge, I think the centre frequency of maximum response would be the geometric mean: $ sqrt{f_{lower} f_{upper}} $
For the RC circuit, upper corner frequency is near $ 1 over {2 pi R_1 C_2} $ while lower corner frequency is near $ 1 over {2 pi R_2C_1} $
Edit:
To get identical response I've added a loading resistor to the LC version (R5:9.091K), and I've added a different loading resistor to the RC version (R4:200K). The value of R2 was changed from 100k previously to 200k, to preserve the lower corner frequency). Now frequency response is identical:
answered 11 hours ago
glen_geek
8,8931916
These two circuits can provide similar bandpass frequency response.
However, the lower-frequency cutoff must be considerably lower than the high-frequency cutoff. This means that the frequency span of the pass-band must be wide, if these two circuits are to provide similar results. For bandpass response with narrow pass-band, the LC circuit is king. Note that the RC bandpass cannot provide anywhere near as much output power as the LC bandpass - it must see a very high-impedance load.
Here's an example to illustrate similar bandpass response of the two circuits (both these examples deliver no power to a load):
If you know the corner frequency of the low-pass edge, and you know the corner frequency of the high-pass edge, I think the centre frequency of maximum response would be the geometric mean: $ sqrt{f_{lower} f_{upper}} $
For the RC circuit, upper corner frequency is near $ 1 over {2 pi R_1 C_2} $ while lower corner frequency is near $ 1 over {2 pi R_2C_1} $
Edit:
To get identical response I've added a loading resistor to the LC version (R5:9.091K), and I've added a different loading resistor to the RC version (R4:200K). The value of R2 was changed from 100k previously to 200k, to preserve the lower corner frequency). Now frequency response is identical:
answered 11 hours ago
glen_geek
8,8931916
edited 8 hours ago
answered 11 hours ago
glen_geek
8,8931916
answered 11 hours ago
glen_geek
8,8931916
answered 11 hours ago
glen_geek
8,8931916
8,8931916
You might provide a description of input and output impedances at DC -- where the circuits behave strikingly different.
– Scott Seidman
10 hours ago
@ScottSeidman Both LC & RC filters have similar response at low frequencies: they both drop at 20 dB/decade (no matter how you load them). Response of both at DC is infinite attenuation. Load resistances tend to affect the corner frequencies & mid-band attenuation.
– glen_geek
9 hours ago
"The same" is what the OP asked. Circuit one has an (ideal) infinite input impedance at DC, and Circuit 2 has an input impedance of R at DC. If nothing else, this can certainly impact your choice for R. Practically, you'd also want to know how you'll be driving each circuit. Not saying you're wrong, or off, but just giving you the opportunity to highlight the differences.
– Scott Seidman
9 hours ago
add a comment |
You might provide a description of input and output impedances at DC -- where the circuits behave strikingly different.
– Scott Seidman
10 hours ago
@ScottSeidman Both LC & RC filters have similar response at low frequencies: they both drop at 20 dB/decade (no matter how you load them). Response of both at DC is infinite attenuation. Load resistances tend to affect the corner frequencies & mid-band attenuation.
– glen_geek
9 hours ago
"The same" is what the OP asked. Circuit one has an (ideal) infinite input impedance at DC, and Circuit 2 has an input impedance of R at DC. If nothing else, this can certainly impact your choice for R. Practically, you'd also want to know how you'll be driving each circuit. Not saying you're wrong, or off, but just giving you the opportunity to highlight the differences.
– Scott Seidman
9 hours ago
You might provide a description of input and output impedances at DC -- where the circuits behave strikingly different.
– Scott Seidman
10 hours ago
You might provide a description of input and output impedances at DC -- where the circuits behave strikingly different.
– Scott Seidman
10 hours ago
@ScottSeidman Both LC & RC filters have similar response at low frequencies: they both drop at 20 dB/decade (no matter how you load them). Response of both at DC is infinite attenuation. Load resistances tend to affect the corner frequencies & mid-band attenuation.
– glen_geek
9 hours ago
@ScottSeidman Both LC & RC filters have similar response at low frequencies: they both drop at 20 dB/decade (no matter how you load them). Response of both at DC is infinite attenuation. Load resistances tend to affect the corner frequencies & mid-band attenuation.
– glen_geek
9 hours ago
"The same" is what the OP asked. Circuit one has an (ideal) infinite input impedance at DC, and Circuit 2 has an input impedance of R at DC. If nothing else, this can certainly impact your choice for R. Practically, you'd also want to know how you'll be driving each circuit. Not saying you're wrong, or off, but just giving you the opportunity to highlight the differences.
– Scott Seidman
9 hours ago
"The same" is what the OP asked. Circuit one has an (ideal) infinite input impedance at DC, and Circuit 2 has an input impedance of R at DC. If nothing else, this can certainly impact your choice for R. Practically, you'd also want to know how you'll be driving each circuit. Not saying you're wrong, or off, but just giving you the opportunity to highlight the differences.
– Scott Seidman
9 hours ago
add a comment |
abdullah ifthiquar is a new contributor. Be nice, and check out our Code of Conduct.
abdullah ifthiquar is a new contributor. Be nice, and check out our Code of Conduct.
abdullah ifthiquar is a new contributor. Be nice, and check out our Code of Conduct.
abdullah ifthiquar is a new contributor. Be nice, and check out our Code of Conduct.
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2
The second one passes DC. The first one does not. Therefore they are not the same.
– Transistor
13 hours ago
may be similar but never the same, at high f, C1/(C1+C2) dominates
– Tony EE rocketscientist
13 hours ago
3
@Transistor no. The second one doesn’t pass DC. It short-circuits it to ground.
– Edgar Brown
11 hours ago
1
OK. I had assumed a real inductor. Thanks.
– Transistor
11 hours ago