Isolated Feedback Power Suplly Circuit

This is a power supply circuit using isolated feedback capabilities of the TL3103 for both current voltage sensing. This supply is powered from the AC power line and has an output of 5 Volts at 1.5 A. Both output voltage and current are sensed and the error voltages are applied to the errer amplifiers of the TL594 PWM control IS. See circuit below :
Isolated Feedback Power Supply
The 24 Volts transformer produces about 35 V. The 20kHz switching frequency is set by the 6-k Ohms resistor and 0.01uF capacitor on pins 6 and 5 , respectively. The TL94 is set for push pull operation by tying pin 13 high. A pair of TIP31 npn transistors are used as switching transistors in a push-pull circuit.