1. The problem statement, all variables and given/known data 2. Relevant equations V0=Vsrz/Rs+rz+VzoRs/Rs+rz-ILrzRs/rz+Rs 3. The attempt at a solution I formulated 4 cases for voltage inputs of 11 and 13.6 V and 0 to 100 mA. The zener current has to be between 3 and 30mA or 103 and 133mA. How can the current be maintained in thes two ranges? does the diode stop conducting? Thank you.