def Z(self):
if self._Z is not None:
return self._Z
if self._Y is not None:
return Zs(1 / self._Y)
if self._Voc is not None:
return Zs(0)
if self._Isc is not None:
return Zs(1 / Ys(0))
raise ValueError('_Isc, _Voc, _Y, or _Z undefined for %s' % self)
def __init__(self, Yval=Ys(0), Ival=Is(0)):
# print('<N> Y:', Yval, 'I:', Ival)
if not isinstance(Yval, Ys):
raise ValueError('Yval not Ys')
if not isinstance(Ival, Is):
raise ValueError('Ival not Is')
self.Y = Yval
self.Isc = Ival
super(Norton, self).__init__()
def admittance(self, Np, Nm):
"""Return s-domain admittance between nodes Np and Nm with independent
sources killed.
"""
new = self.kill()
# Connect 1 V s-domain voltage source between nodes and
# measure current.
new._add('Vin_ %d %d {DiracDelta(t)}' % (Np, Nm))
If = -new.Vin_.I
new.remove('Vin_')
return Ys(If.laplace())
def Amatrix(self, N1p, N1m, N2p, N2m):
"""Create A matrix from network, where:
I1 is the current flowing into N1p and out of N1m
I2 is the current flowing into N2p and out of N2m
V1 is V[N1p] - V[N1m]
V2 is V[N2p] - V[N2m]
"""
from lcapy.twoport import AMatrix
if self.Voc(N1p, N1m) != 0 or self.Voc(N2p, N2m) != 0:
raise ValueError('Network contains independent sources')
try:
self.add('V1_ %d %d {DiracDelta(t)}' % (N1p, N1m))
# A11 = V1 / V2 with I2 = 0
# Apply V1 and measure V2 with port 2 open-circuit
A11 = Hs(self.V1_.V.laplace() / self.Voc(N2p, N2m).laplace())
# A12 = V1 / I2 with V2 = 0
# Apply V1 and measure I2 with port 2 short-circuit
A12 = Zs(self.V1_.V.laplace() / self.Isc(N2p, N2m).laplace())
self.remove('V1_')
self.add('I1_ %d %d {DiracDelta(t)}' % (N1p, N1m))
# A21 = I1 / V2 with I2 = 0
# Apply I1 and measure I2 with port 2 open-circuit
A21 = Ys(-self.I1_.I.laplace() / self.Voc(N2p, N2m).laplace())
# A22 = I1 / I2 with V2 = 0
# Apply I1 and measure I2 with port 2 short-circuit
A22 = Hs(-self.I1_.I.laplace() / self.Isc(N2p, N2m).laplace())
self.remove('I1_')
A = AMatrix(A11, A12, A21, A22)
return A
except ValueError:
raise ValueError('Cannot create A matrix')
def Y(self):
if self._Y is not None:
return self._Y
return Ys(1 / self.Z)
def __init__(self, Yval):
self.args = (Yval, )
Yval = Ys(Yval)
self._Z = 1 / Yval
def __init__(self, Gval):
self.args = (Gval, )
self.G = cExpr(Gval)
self._Z = 1 / Ys.G(self.G)
def __init__(self, Yval):
self.args = (Yval, )
Yval = Ys(Yval)
super(Y, self).__init__(Yval)
def __init__(self, Gval):
self.args = (Gval, )
Gval = cExpr(Gval, positive=True)
super(G, self).__init__(Ys.G(Gval))
self.G = Gval
def Y(self):
return Ys(1 / self.Z)
def __init__(self, Ival):
self.args = (Ival, )
Ival = sExpr(Ival)
super(sI, self).__init__(Ys(0), Is(Ival))
def __init__(self, Ival):
super(CurrentSource, self).__init__(Ys(0), Is(Ival))