capacitance multiplier study

git-svn-id: https://svn.code.sf.net/p/freetel/code@2545 01035d8c-6547-0410-b346-abe4f91aad63

diff --git a/misc/capmult/capmult.asc b/misc/capmult/capmult.asc
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--- /dev/null
+++ b/misc/capmult/capmult.asc
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+Version 4
+SHEET 1 880 680
+WIRE 144 -96 48 -96
+WIRE 320 -96 224 -96
+WIRE 464 -96 320 -96
+WIRE 48 -80 48 -96
+WIRE 320 -64 320 -96
+WIRE 464 -64 464 -96
+WIRE 528 -64 528 -96
+WIRE 48 32 48 0
+WIRE 320 32 320 0
+WIRE 320 32 48 32
+WIRE 464 32 464 16
+WIRE 464 32 320 32
+WIRE 528 32 528 16
+WIRE 528 32 464 32
+WIRE 48 48 48 32
+WIRE 128 128 48 128
+WIRE 320 128 208 128
+WIRE 464 128 320 128
+WIRE 48 160 48 128
+WIRE 320 160 320 128
+WIRE 464 208 464 128
+WIRE 320 256 320 240
+WIRE 400 256 320 256
+WIRE 464 336 464 304
+WIRE 528 336 528 304
+WIRE 48 416 48 240
+WIRE 320 416 320 320
+WIRE 320 416 48 416
+WIRE 464 416 320 416
+WIRE 528 416 464 416
+WIRE 48 432 48 416
+FLAG 48 48 0
+FLAG 48 432 0
+SYMBOL voltage 48 144 R0
+WINDOW 123 0 0 Left 2
+WINDOW 39 0 0 Left 2
+SYMATTR InstName V1
+SYMATTR Value SINE(12 0.1 100)
+SYMBOL res 224 112 R90
+WINDOW 0 0 56 VBottom 2
+WINDOW 3 32 56 VTop 2
+SYMATTR InstName R1
+SYMATTR Value 1
+SYMBOL res 336 256 R180
+WINDOW 0 36 76 Left 2
+WINDOW 3 36 40 Left 2
+SYMATTR InstName R2
+SYMATTR Value 5E3
+SYMBOL res 480 432 R180
+WINDOW 0 36 76 Left 2
+WINDOW 3 36 40 Left 2
+SYMATTR InstName R3
+SYMATTR Value 100
+SYMBOL cap 304 256 R0
+SYMATTR InstName C1
+SYMATTR Value 1E-6
+SYMBOL npn 400 208 R0
+WINDOW 0 73 4 Left 2
+WINDOW 3 73 34 Left 2
+SYMATTR InstName Q1
+SYMATTR Value 2N3904
+SYMBOL voltage 48 -96 R0
+WINDOW 123 0 0 Left 2
+WINDOW 39 0 0 Left 2
+SYMATTR InstName V2
+SYMATTR Value SINE(12 0.1 100)
+SYMBOL res 240 -112 R90
+WINDOW 0 0 56 VBottom 2
+WINDOW 3 32 56 VTop 2
+SYMATTR InstName R4
+SYMATTR Value 1
+SYMBOL res 480 32 R180
+WINDOW 0 36 76 Left 2
+WINDOW 3 36 40 Left 2
+SYMATTR InstName R5
+SYMATTR Value 100
+SYMBOL cap 304 -64 R0
+SYMATTR InstName C2
+SYMATTR Value 1E-6
+SYMBOL cap 528 -112 R90
+WINDOW 0 0 32 VBottom 2
+WINDOW 3 32 32 VTop 2
+SYMATTR InstName C3
+SYMATTR Value 1E-6
+SYMBOL cap 528 288 R90
+WINDOW 0 0 32 VBottom 2
+WINDOW 3 32 32 VTop 2
+SYMATTR InstName C4
+SYMATTR Value 1E-6
+SYMBOL res 512 -80 R0
+SYMATTR InstName R6
+SYMATTR Value 1E6
+SYMBOL res 512 320 R0
+SYMATTR InstName R7
+SYMATTR Value 1E6
+TEXT 0 464 Left 2 !.tran 0 1 0

diff --git a/misc/capmult/capmult.m b/misc/capmult/capmult.m
new file mode 100644 (file)
index 0000000..024f2d0
--- /dev/null
+++ b/misc/capmult/capmult.m
@@ -0,0 +1,30 @@
+% capmult.m
+% David Rowe 17 Dec 2015
+%
+% Working for capaitance multiplier (that maybe isn't a capacitance multipler)
+
+Vi = 0.1/sqrt(2);
+C = 1E-6;
+Rs = 1;
+Rl = 100;
+Rb = 5000;
+f = 100;
+
+w = 2*pi*f;
+Xc = 1/(w*C);
+
+% Standard circuit, voltage division, ignore Rl as its >> Rs
+
+Vo1 = Vi*j*Xc/(Rs+j*Xc);
+
+% Cap Multiplier circuit, voltage division, ignore Rb as its big compared
+% to Xc
+
+Vo2 = Vi*j*Xc/(Rb+j*Xc);
+
+printf("standard: %3.0f mVrms   Cap Mult: %3.0f mVrms\n", abs(Vo1)*1E3, abs(Vo2)*1E3);
+
+
+
+
+

diff --git a/misc/capmult/capmult_sch.png b/misc/capmult/capmult_sch.png
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