Given three phase fullwave with center tapped transformer with 220 Vac source voltage, determine: Vdc, Vrms, Pdc, RF, and efficiency.

4.) A transformer has a primary coil with 300 windings, and secondary coil has 400 windings. The input AC power supply is 120 volts (Vrms). A) Is this a step-up or step-down transformer? B) What is the rms voltage across the output terminals (Vrms)? C) What is the peak voltage across the output terminals (Vmax)? Primary Secondary imm ac input

The three-phase full-wave converter shown below is used to rectify the three phase (Y-connection) source signals. The six Thyristor are triggered in the sequence shown. Sketch for firing angle (a=90°) the output voltage (Vo), the phase current, the current for any two Thyristor in any one leg, and the load current (Ia). Then calculate (a) Thyristor average and r.m.s current. (b) Supply average and r.m.s current. (c) The normalized average output voltage. (d) The maximum output voltage. [Vdc = [1 - cos(60+ a)] Vml T If the line-to-neutral voltages are defined as 11 T, T T STA T. Load I sin od sin() ex-> Solve the question sin(with your own hands the corresponding line-to-line voltages are √31% sin (out + ) ---√(4)

Describe the purpose and operation of transformers in electrical power systems.

Vr 3. For a 1.2 accuracy class potential transformer used at a lagging phase angle y of 10', the RCF value is A. 0.991. B. 0.988. C. 0.977. D. 0.999. primary connection scheme that must be used with

4) A single-phase full-wave AC voltage controller consists of two SCRs connected in invers-parallel. The supply voltage is 220V at 50Hz. The controller is used to control heater element of 2500W in an electric oven. The trigger angle is 30o. i) Draw the circuit diagram ii) sketch compatible waveforms for the supply, load and SCR voltages. iii) calculate the rms value of the load voltage and current. iv) Determine the input power factor of the circuit. v) Calculate the average value of the SCR current.