jrive

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3 years, 318 days

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These are questions asked by jrive

Why won't Maple solve any of these inequalities for Q?

At first I tried solving the system of equations, but then I tried solving the inequalities individually for Q, and those too could not be solved by Maple.  What am I doing wrong?
 

restart

 

assume(R1, real, R2, real, RL, real, XC1, real, XC2, real, XL1, real)

additionally(R1 > 0, R2 > 0, RL > 0, XC1 > 0, XC2 > 0, XL1 > 0)

 

 

eq3 := R1*(4*Q^2+1)-RL > 0

0 < R1*(4*Q^2+1)-RL

(1)

eq4 := 4*Q^2*R1*RL-(R1-RL)^2 >= 0

0 <= 4*Q^2*R1*RL-(R1-RL)^2

(2)

eq5 := Rs^2*(RL-R1)/Q^2+R1^2*RL > 0

0 < Rs^2*(RL-R1)/Q^2+RL*R1^2

(3)

 

``

sys1 := {eq3, eq4, eq5}

`assuming`([solve(sys1, {Q})], [R1 > RL])

`assuming`([solve(sys1, {Q})], [R1 < RL])

solve(sys1, {Q})

Warning, solutions may have been lost

 

solve(eq3, Q)

Warning, solutions may have been lost

 

solve(eq4, Q)

Warning, solutions may have been lost

 

solve(eq5, Q)

Warning, solutions may have been lost

 

``


 

Download pi-filter_anal_copy.mw

I need to use the fact that the expression under the radical in a larger expression is >0.

How do I programmaticaly "grab" the radical term to include it in an equation such as for example:

eq1:= b^2-4 a c>0

where lhs term would have come from a previous derivation or solution ?

Thank you...

How can I get Maple to simplify expressions into more meaningful forms?

For example, 

xc1 := -(2*Q*R1 + sqrt(4*Q^2*R1*RL - R1^2 + 2*R1*RL - RL^2))*R1/(4*Q^2*R1 + R1 - RL)

 

The numerator, under the radical, is more meaningful as sqrt(4 Q^2 R1 RL-(R1-RL)^2).

 

Similarly, the denominator can be simplified to Rs(4 Q^2+1)-RL.  

 

How do I get Maple to get me there?

I have Maple solve a system of equations.  I then want to assign the result to the different variables for use later in the worksheet.  How do I do this?
 

 

{C1 = .6666666670*Ceq, C2 = 2.000000002*Ceq, L1 = 0.1377592863e-15/Ceq, R1 = 0.8802817643e-8/Ceq}

(24)

c1 := sol3[1]

C1 = .6666666670*Ceq

(25)

l1 := sol3[2]

C2 = 2.000000002*Ceq

(26)

r1 := sol3[3]

L1 = 0.1377592863e-15/Ceq

(27)

Solutions, C2=10pf

Ceqsol := 20*e-12

20*e-12

(28)

C1sol := subs(Ceq = Ceqsol, c1)

C1 = 13.33333334*e-8.000000004

(29)
 

 

 


First, all I want to do is assign the solution value for C1 to C1.  Not being able to do this, I try to assign C1 to "different" variable c1, but the assignment is C1~=.66667* Ceq, instead of just the value of C1.  Later, I then try to substitute the value of Ceq, to get the solution for c1, and instead of just getting the value, I get  that C1= 13.33x10^-8 is assigned to C1sol, again instead of just the value, 13.33x10^-8.  How do I just assign the values to these variables instead of the expressions?

 

Thank you.

Download new_filter_solution.mw

How do I get Maple to simplify:

 

Io := I Cp Vin L1/(M sqrt(Cp L1))

 

to :  I sqrt(L1 CP) Vin/ M  ?

 

Furthermore, if  w = 1/sqrt(L1 *CP),  how do I get Maple to display the solution or the simplification as:

I*Vin/(w M) ?

I've t ried multiple substitutions and simplifications to no avail.

 

Thank you.

Jorge

 

I*Cp*RL*Vin*L1/(M*(Cp*L1)^(1/2))

(4)

simplify(I*Cp*RL*Vin*L1/(M*(L1*Cp)^(1/2)), 'symbolic')

I*Cp^(1/2)*RL*Vin*L1^(1/2)/M

(5)

 

NULL

Io := Vores/RL

I*Cp*Vin*L1/(M*(Cp*L1)^(1/2))

(6)

simplify(I*Cp*Vin*L1/(M*(L1*Cp)^(1/2)))

I*Cp*Vin*L1/(M*(Cp*L1)^(1/2))

(7)

simplify(I*Cp*Vin*L1/(M*(L1*Cp)^(1/2)), 'assume = real')

I*Cp*Vin*L1/(M*(Cp*L1)^(1/2))

(8)

combine(Vores/RL, power)

I*Cp*Vin*L1/(M*(Cp*L1)^(1/2))

(9)

factor(I*Cp*Vin*L1/(M*(L1*Cp)^(1/2)))

I*Cp*Vin*L1/(M*(Cp*L1)^(1/2))

(10)

combine(I*Cp*Vin*L1/(M*(L1*Cp)^(1/2)), radical)

I*Cp*Vin*L1/(M*(Cp*L1)^(1/2))

(11)

I*Cp*Vin*L1/(M*(L1*Cp)^(1/2))

cancel(I*Cp*Vin*L1/(M*(Cp*L1)^(1/2)))

(12)

simplify(cancel(I*Cp*Vin*L1/(M*(L1*Cp)^(1/2))), 'assume = real')

I*Cp*Vin*L1/(M*(Cp*L1)^(1/2))

(13)

simplify(I*Cp*Vin*L1/(M*(L1*Cp)^(1/2)), 'radical')

I*Cp*Vin*L1/(M*(Cp*L1)^(1/2))

(14)

simplify(I*Cp*Vin*L1/(M*(L1*Cp)^(1/2)), 'symbolic')

I*Cp^(1/2)*Vin*L1^(1/2)/M

(15)

``


 

Download Resonant_xformer.mw

 

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