Download - Wolfram Research

452 4. Appendix
V1
node1
node2
An open-circuit branch is essentially the same as an independent current source with zero source
current. The value specification is ignored. However, it should be set to 0 (zero) to reflect the fact
that the source current is zero. Note that open circuits are mostly used implicitly as controlling
branches of voltage-controlled sources but they may also be used explicitly in a netlist when a
voltage meter is needed. In the latter case, modified nodal analysis employs a special matrix fill-in
pattern which augments the vector of unknown node voltages by the branch voltage across the open
circuit. This allows for directly computing the differential voltage between two nodes neither of
which is ground. Without the voltage sensor, two node voltages would have to be solved for and
then subtracted from one another, which would be computationally more expensive.
4.2.8 ShortCircuit
type name
syntax
ShortCircuit {SCname, {node1, node2}, 0}
denotes a short-circuit branch
Circuit element type ShortCircuit.
I1
node1
node2
A short-circuit branch is essentially the same as a voltage source with zero source voltage. The
value specification is ignored. However, it should be set to 0 (zero) to reflect the fact that the
source voltage is zero. Note that short circuits are mostly used implicitly as controlling branches of
current-controlled sources. They may also be used explicitly as current meters in combination with
modified nodal analysis.