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AOE fig. 2.30 phasor diagram

M

Mr.CRC

Jan 1, 1970
0
Hi:


The phasor diagram for the constant amplitude phase shifter fig. 2.29 in
AOE 2nd ed. is upside down.

That is, the Vout phasor should always point in the 3rd or 4th quadrants
so that the output phase always is in the open interval (-180, 0). Ie.,
the Vout phase must always be lagging V1. But the text shows it
pointing up in the (0, 180) degrees range, which cannot be.

A while back I did a full analysis of this thing, and concluded that the
fig. 2.30 was upside down, but left it at that.

A simple LTspice analysis confirms that Vout must always be in the range
of (-180, 0) degrees:

Has this little discrepancy ever bugged anyone else?

-------------------------------------------------------
Version 4
SHEET 1 880 680
WIRE 192 16 112 16
WIRE 112 48 112 16
WIRE 112 160 112 128
WIRE 112 160 32 160
WIRE 32 176 32 160
WIRE 112 192 112 160
WIRE 112 304 112 272
WIRE 192 304 112 304
FLAG 32 176 0
SYMBOL voltage 112 288 R180
WINDOW 0 41 57 Left 0
WINDOW 3 24 16 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value SINE(0 1 50)
SYMBOL voltage 112 32 R0
WINDOW 0 -65 37 Left 0
WINDOW 3 -259 97 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value SINE(0 1 50 0 0 180)
TEXT -148 310 Left 0 !.tran 100m
 
J

John S

Jan 1, 1970
0
Hi:


The phasor diagram for the constant amplitude phase shifter fig. 2.29 in
AOE 2nd ed. is upside down.

That is, the Vout phasor should always point in the 3rd or 4th quadrants
so that the output phase always is in the open interval (-180, 0). Ie.,
the Vout phase must always be lagging V1. But the text shows it
pointing up in the (0, 180) degrees range, which cannot be.

A while back I did a full analysis of this thing, and concluded that the
fig. 2.30 was upside down, but left it at that.

A simple LTspice analysis confirms that Vout must always be in the range
of (-180, 0) degrees:

Has this little discrepancy ever bugged anyone else?

-------------------------------------------------------
Version 4
SHEET 1 880 680
WIRE 192 16 112 16
WIRE 112 48 112 16
WIRE 112 160 112 128
WIRE 112 160 32 160
WIRE 32 176 32 160
WIRE 112 192 112 160
WIRE 112 304 112 272
WIRE 192 304 112 304
FLAG 32 176 0
SYMBOL voltage 112 288 R180
WINDOW 0 41 57 Left 0
WINDOW 3 24 16 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value SINE(0 1 50)
SYMBOL voltage 112 32 R0
WINDOW 0 -65 37 Left 0
WINDOW 3 -259 97 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value SINE(0 1 50 0 0 180)
TEXT -148 310 Left 0 !.tran 100m
----------------------------------------------


So, where is C and R?
 
M

Mr.CRC

Jan 1, 1970
0
John said:
So, where is C and R?

Sorry, I often overlook the loss of a bunch of lines copy/pasting btw.
two Linux apps.

Try this:


Version 4
SHEET 1 880 680
WIRE 192 16 112 16
WIRE 256 16 192 16
WIRE 432 16 256 16
WIRE 112 48 112 16
WIRE 256 48 256 16
WIRE 432 48 432 16
WIRE 112 160 112 128
WIRE 112 160 32 160
WIRE 256 160 256 112
WIRE 320 160 256 160
WIRE 336 160 320 160
WIRE 432 160 432 112
WIRE 496 160 432 160
WIRE 512 160 496 160
WIRE 32 176 32 160
WIRE 256 176 256 160
WIRE 432 176 432 160
WIRE 112 192 112 160
WIRE 112 304 112 272
WIRE 176 304 112 304
WIRE 256 304 256 256
WIRE 256 304 176 304
WIRE 432 304 432 256
WIRE 432 304 256 304
FLAG 32 176 0
FLAG 320 160 Vo1
FLAG 176 304 V1
FLAG 192 16 V2
FLAG 496 160 Vo2
SYMBOL voltage 112 288 R180
WINDOW 0 41 57 Left 0
WINDOW 3 24 16 Left 0
WINDOW 123 24 -12 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value SINE(0 1 50)
SYMATTR Value2 AC 1 0
SYMBOL voltage 112 32 R0
WINDOW 0 -65 37 Left 0
WINDOW 3 -259 97 Left 0
WINDOW 123 -259 125 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value SINE(0 1 50 0 0 180)
SYMATTR Value2 AC 1 180
SYMBOL cap 240 48 R0
SYMATTR InstName C1
SYMATTR Value 1�
SYMBOL res 240 160 R0
SYMATTR InstName R1
SYMATTR Value 200
SYMBOL cap 416 48 R0
SYMATTR InstName C2
SYMATTR Value 1�
SYMBOL res 416 160 R0
SYMATTR InstName R2
SYMATTR Value 100k
TEXT -308 238 Left 0 !.ac oct 16 1 1k
 
J

John S

Jan 1, 1970
0
Hi:


The phasor diagram for the constant amplitude phase shifter fig. 2.29 in
AOE 2nd ed. is upside down.

That is, the Vout phasor should always point in the 3rd or 4th quadrants
so that the output phase always is in the open interval (-180, 0). Ie.,
the Vout phase must always be lagging V1. But the text shows it
pointing up in the (0, 180) degrees range, which cannot be.

A while back I did a full analysis of this thing, and concluded that the
fig. 2.30 was upside down, but left it at that.

A simple LTspice analysis confirms that Vout must always be in the range
of (-180, 0) degrees:

Has this little discrepancy ever bugged anyone else?

It appears that you are correct. The last time I studied it, I didn't
catch the error because I assumed V1 was at the top and V2 at the bottom.

It doesn't really bother me, however. I'll just go back to my mistaken
assumption.

John S
 
J

John S

Jan 1, 1970
0
It appears that you are correct. The last time I studied it, I didn't
catch the error because I assumed V1 was at the top and V2 at the bottom.

It doesn't really bother me, however. I'll just go back to my mistaken
assumption.

John S

Belay that. Swapping sources won't fix it either. I just missed catching
the error, I guess. Good eye.

John S
 
J

John S

Jan 1, 1970
0
Belay that. Swapping sources won't fix it either. I just missed catching
the error, I guess. Good eye.

John S

Well, crap! Yes it will fix it. Someday I'll get my head on straight.

John S
 
J

josephkk

Jan 1, 1970
0
Well, crap! Yes it will fix it. Someday I'll get my head on straight.

John S

Uh-oh, you just had a human moment.

;-))
 

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