Study of Voltage Regulator LAB CEII SEM V

Study of Voltage Regulator LAB: - CEII (SEM V EXTC)

Aim and Apparatus Aim : Design and study of voltage regulator Apparatus : IC 723, Resistors, Capacitors, Unregulated Power supply, Multimeter. fig 1 LAB: - CEII (SEM V EXTC)

Theory • IC 723 has unregulated dc supply at input between 11. 5 V to 40 V. It can withstand maximum load current of 150 m. A. Internal power dissipation is about 800 m. W. It has low temperature and high ripple rejection. The output voltage can be adjusted between 2 V to 37 V. The pin configuration of IC 723 is shown in fig 1. Reference : http: //www. ti. com/lit/ds/symlink/lm 723. pdf LAB: - CEII (SEM V EXTC)

The functional block diagram of IC 723 consists of a reference generating block. The main function of this block is to generate a fixed reference voltage internally with the help of zener diode. The error amplifier is a high gain differential amplifier with two inputs. The noninverting terminal is connected to the internally generated reference voltage. The inverting terminal is connected to full regulated output voltage. The series pass transistor is driven by the error amplifier. This transistor acts as a variable resistor and regulates the output voltage. The circuitry to limit the current is used to stop the flow of excess current passing through the circuit. The frequency compensation terminal is used to decide the frequency response of the error amplifier. The simplified internal structure of IC 723 is shown in fig 2: The maximum ratings of IC 723 is shown in fig 3: Reference : www. circuitstoday. com fig 2 Sr No Parameter Maximum value 1 Pulsed Voltage 50 V 2 Continuous Voltage 40 V 3 40 V 6 Input Output Voltage Differential Maximum Amplifier Input Voltage-Either Input Maximum Amplifier Input Voltage-Differential Internal Power Dissipation 660 m. W 7 Output Current 150 m. A 4 5 fig 3 LAB: - CEII (SEM V EXTC) 8. 5 V 5 V

Design Problem • LAB: - CEII (SEM V EXTC)

• Procedure: 1)Design the given problem and connect the circuit. 2)Apply unregulated input voltage at pin 12. 3)Check the output at pin 2 using the multimeter. 4)Note the output and vary the input voltage. 5)Repeat steps 2 to 4 till Vcc=25 V. • Observation: Input Unregulated Voltage (V) Regulated Output Voltage (V) • Result : The regulator output is constant at 5. 07 over range of inputs of 15 -25 V using IC 723. LAB: - CEII (SEM V EXTC)

References • Internet and Books by Sergio Franco and Ramakant Gaykwad LAB: - CEII (SEM V EXTC)