 where
 where  is the conductance,
 is the conductance,  is the power loss in the arc, and
 is the power loss in the arc, and  is the arc time constant. Use the following blocks to implement this:
 is the arc time constant. Use the following blocks to implement this:- Gain: For the  factor. factor.
- Divide: To compute  . .
- Sum: To implement the subtraction  . .
- Integrator: To integrate the rate of change of conductance.



