M
Mr.CRC
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
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
