Design an adder circuit using op-amp to satisfy following equation:
-Vo = V1 + 3 V2 + 2 V3 + 2V4 + 4V5
The supply voltage of the op-amp is +/- 13V and output saturation voltage is +/- 12 V.
The circuit should always operate in its linear range. What are the minimum- maximum voltage values of V1, V2, V3, V4 and V5 when only one of them is connected to the input at a given time (i.e. other input voltages are zero)? What is the value of maximum voltage Vi if V1 = V2 = V3 = V4 = V5 = Vi ?)
A three–phase transformer has its primary winding delta-connected and its secondary winding starconnected. The number of turns per phase on the primary is four times that on a secondary, and the secondary line voltage is 400V. A balanced load of 20kW, at power factor 0.8, is connected across the secondary terminals. Assuming an ideal transformer, calculate the primary voltage and the phase and line currents on the secondary and primary sides. Sketch a circuit diagram and indicate the values of the voltages and currents on the diagram.