Next to the standard effort and flow sources, that generate a constant effort and flow, bond graph modeling also allows the use of so called modulated sources. In these sources the resulting effort or flow are equal to a (fluctuating) value provided by an input signal. Two types of modulated sources are know: the modulated effort source MSe and the modulated flow source MSf. In the table below the effort and flow description of the source elements is shown.
element |
bond graph element |
equation |
modulated effort source |
e = u, f = free |
|
modulated flow source |
f = u, e = free |
The direction of effort and flow for sources are restricted. In other words: the MSe-element (effort-out) and MSf-element (effort-in) have a fixed causality.