def test_wire_mutual_inductance():
# Paul MTL P5.4
rw = 7.5
ref = Wire(0, 0, rw)
wi = Wire(-50, 0, rw)
wj = Wire(50, 0, rw)
L = mtl.wire_mutual_inductance(wi, wj, ref)
assert L == approx(0.241e-6, rel=0.001)
def test_two_wire_capacitance_bad_method():
rw = 1e-3
s = 10e-3
wires = [Wire(-0.5 * s, 0, rw)]
ref = Wire(0.5 * s, 0, rw)
pair = mtl.WireMtl(wires, ref)
with pytest.raises(Exception):
pair.capacitance(method='junk')
def test_two_wire_inductance():
rw = 7.5
s = 50
wires = [Wire(-0.5 * s, 0, rw)]
ref = Wire(0.5 * s, 0, rw)
pair = mtl.WireMtl(wires, ref)
L = mtl.wire_inductance(s, rw)
assert pair.inductance()[[0]] == approx(L, rel=0.02)
def test_two_wire_capacitance():
rw = 7.5
s = 50
wires = [Wire(-0.5 * s, 0, rw)]
ref = Wire(0.5 * s, 0, rw)
pair = mtl.WireMtl(wires, ref)
C = mtl.wire_capacitance(s, rw)
assert pair.capacitance()[[0]] == approx(C, rel=0.02, abs=1e-14)
def test_wire_self_inductance():
# Paul MTL P5.4
rw = 7.5
di0 = 50
ref = Wire(0, 0, rw)
wire = Wire(di0, 0, rw)
L = mtl.wire_self_inductance(wire, ref)
assert L == approx(0.759e-6, abs=0.001e-6)
def test_two_wire_capacitance_fdm_near():
rw = 1e-3
s = 3e-3
wires = [Wire(-0.5 * s, 0, rw)]
ref = Wire(0.5 * s, 0, rw)
pair = mtl.WireMtl(wires, ref)
expected = mtl.wire_capacitance(s, rw)
C = pair.capacitance(method='fdm', fdm_params={'dx': rw / 10})
assert C == approx(expected, rel=0.05, abs=0.1e-12)
def test_two_wire_capacitance_fdm_diagonal():
rw = 1e-3
x2 = y2 = 6e-3
wires = [Wire(0, 0, rw)]
ref = Wire(x2, y2, rw)
pair = mtl.WireMtl(wires, ref)
expected = pair.capacitance(method='ana')
C = pair.capacitance(method='fdm')
assert C == approx(expected, rel=0.05, abs=0.1e-12)
def test_two_wire_capacitance_fdm():
rw = 1e-3
s = 8e-3
wires = [Wire(-0.5 * s, 0, rw)]
ref = Wire(0.5 * s, 0, rw)
pair = mtl.WireMtl(wires, ref)
expected = pair.capacitance(method='ana')
C = pair.capacitance(method='fdm')
assert C == approx(expected, rel=0.05, abs=0.1e-12)
def test_two_wire_inductance_diagonal():
rw = 7.5
s = 50
x2 = y2 = s / np.sqrt(2)
wires = [Wire(0, 0, rw)]
ref = Wire(x2, y2, rw)
pair = mtl.WireMtl(wires, ref)
L = mtl.wire_inductance(s, rw)
assert pair.inductance()[[0]] == approx(L, rel=0.02)
def test_two_wire_capacitance_diagonal():
rw = 7.5
s = 50
x2 = y2 = s / np.sqrt(2)
wires = [Wire(0, 0, rw)]
ref = Wire(x2, y2, rw)
pair = mtl.WireMtl(wires, ref)
C = mtl.wire_capacitance(s, rw)
assert pair.capacitance()[[0]] == approx(C, rel=0.02, abs=1e-14)
def test_three_wire_capacitance():
# Paul MTL P5.4
rw = 7.5
s = 50
wires = [Wire(s, 0, rw), Wire(-s, 0, rw)]
ref = Wire(0, 0, rw)
bus = mtl.WireMtl(wires, ref)
C = bus.capacitance()
expected = np.array([[16.3, -5.17], [-5.17, 16.3]]) * 1e-12
assert C == approx(expected, rel=0.001, abs=1e-14)
def test_three_wire_inductance():
# Paul MTL P5.4
rw = 7.5
s = 50
wires = [Wire(s, 0, rw), Wire(-s, 0, rw)]
ref = Wire(0, 0, rw)
bus = mtl.WireMtl(wires, ref)
L = bus.inductance()
expected = np.array([[0.759, 0.241], [0.241, 0.759]]) * 1e-6
assert L == approx(expected, rel=0.001)
def test_two_wire_inductance_shield():
# Paul MTL P5.10
rw = 0.1905e-3
s = 4 * rw
rs = 4 * rw
wires = [Wire(-0.5 * s, 0, rw), Wire(0.5 * s, 0, rw)]
ref = Shield(rs)
pair = mtl.WireMtl(wires, ref)
L = pair.inductance()
expected = np.array([[0.2197, 0.0446], [0.0446, 0.2197]]) * 1e-6
assert L == approx(expected, rel=0.001)
def test_two_wire_capacitance_plane():
# Paul MTL P5.7
rw = 0.04064
s = 2
h = 2
wires = [Wire(-0.5 * s, h, rw), Wire(0.5 * s, h, rw)]
ref = Plane()
pair = mtl.WireMtl(wires, ref)
C = pair.capacitance()
expected = np.array([[12.5, -2.19], [-2.19, 12.5]]) * 1e-12
assert C == approx(expected, rel=0.001, abs=1e-14)
def test_two_wire_inductance_plane():
# Paul MTL P5.7
rw = 0.04064
s = 2
h = 2
wires = [Wire(-0.5 * s, h, rw), Wire(0.5 * s, h, rw)]
ref = Plane()
pair = mtl.WireMtl(wires, ref)
L = pair.inductance()
expected = np.array([[0.918, 0.161], [0.161, 0.918]]) * 1e-6
assert L == approx(expected, rel=0.001)
def test_two_wire_capacitance_fdm_rw2():
rw1 = 1e-3
rw2 = 2e-3
s = 20e-3
wires = [Wire(-0.5 * s, 0, rw1)]
ref = Wire(0.5 * s, 0, rw2)
pair = mtl.WireMtl(wires, ref)
expected = pair.capacitance(method='ana')
print(expected)
C = pair.capacitance(method='fdm')
assert C == approx(expected, rel=0.05, abs=0.1e-12)
def test_two_wire_capacitance_shield():
# Paul MTL P5.11
rw = 0.1905e-3
s = 4 * rw
rs = 4 * rw
wires = [Wire(-0.5 * s, 0, rw), Wire(0.5 * s, 0, rw)]
ref = Shield(rs)
pair = mtl.WireMtl(wires, ref)
C = pair.capacitance()
expected = np.array([[52.8, -10.73], [-10.73, 52.8]]) * 1e-12
assert C == approx(expected, rel=0.001, abs=1e-14)
def test_one_wire_capacitance_shield():
rw = 0.5e-3
rs = 4e-3
er = 5.2
wires = [Wire(0, 0, rw)]
ref = Shield(rs)
cable = mtl.WireMtl(wires, ref, er)
C = cable.capacitance()
expected = coax.capacitance(rw, rs, er)
assert C == approx(expected, rel=0.001, abs=1e-14)
def test_export():
PITCH = 1.27e-3
RW = 0.1905e-3
INS_ER = 3.5
INS_THK = 0.254e-3
# CR Paul MTL Table 5.5
# With / without dielectric
# C11 37.432 22.494 pF/m
# C12 -18.716 -11.247 pF/m
# C22 24.982 16.581 pF/m
capacitance = []
options = ((0.0, 1.0, 'no_'), (INS_THK, INS_ER, ''))
for (ins_thk, ins_er, prefix) in options:
filename = f'ribbon_{prefix}dielectric.lst'
ref = Wire(0, 0, RW, ins_thk, ins_er)
# ref = Plane()
# ref = Shield(3 * PITCH)
wires = [
Wire(PITCH, 0, RW, ins_thk, ins_er),
Wire(2 * PITCH, 0, RW, ins_thk, ins_er)
]
mtl = WireMtl(wires, ref)
wire_mtl_to_fastcap2d(mtl, filename)
try:
capacitance.append(fc.run_fastercap(filename))
except Exception as ex:
print(ex)
fc.plot_list_file(filename)
if len(capacitance) == 2:
print('*****')
print('No Dielectric (pF/m):')
print(capacitance[0] * 1e12)
print('With Dielectric (pF/m):')
print(capacitance[1] * 1e12)
plt.show()
def test_shield_contains_outside():
a = Wire(2.0, 0, 0.5)
s = Shield(1.0)
assert not s.contains(a)
def test_shield_contains_overlap():
a = Wire(0.6, 0, 0.5)
s = Shield(1.0)
assert not s.contains(a)
def test_radius_zero():
with pytest.raises(ValueError):
Wire(0, 0, 0)
def test_shield_contains_wire_on_edge():
a = Wire(0, 0.5, 0.5)
s = Shield(1.0)
assert s.contains(a)
def test_shield_contains():
a = Wire(0, 0.0, 0.5)
s = Shield(1.0)
assert s.contains(a)
def test_shield_contains_wire_larger():
a = Wire(0, 0, 1.5)
s = Shield(1.0)
assert not s.contains(a)
def test_plane_height():
a = Wire(0, 2.0, 0.5)
p = Plane()
assert p.height_of(a) == approx(2.0)
def test_offset_zero():
a = Wire(1, 2, 0.5)
assert a.offset(1, 2) == approx(0)
def test_offset():
a = Wire(1, 1, 0.5)
assert a.offset() == approx(np.sqrt(2))
def test_angle_to_ortho():
a = Wire(1, 0, 0.5)
b = Wire(0, 1, 0.5)
assert a.angle_to(b) == approx(0.5 * np.pi)
def test_angle_to():
a = Wire(-1, 0, 0.5)
b = Wire(1, 0, 0.5)
assert a.angle_to(b) == approx(-np.pi)
assert b.angle_to(a) == approx(np.pi)
