12- In a single-phase full-wave controlled rectifier with center tapped transformer and resistive load, it is desired to get an average load voltage of 140 V. Determine the firing angle if the ac supply voltage is 200 V. If the average load power is 700 W, calculate the average load current and design the thyristor. The volt-drop across each thyristor Von during conduction is 1.8V. Determine the average conduction losses of the thyristors. (homework 10-2019)