EGN 3310 Midterm: Exam 2 instructions

Which interview question shows that you understand the significance of the event you are asking about?

A. What happened to you on Monday, Nov. 5th?

B. What are the names of the people involved? 

C. Who was with you on that exhilarating day on the mountain?

Question 5  (IEIIQ18)

A simple Zener shunt voltage regulator is to supply a 10 V to load of 100 mA, the input supply voltage varies between 15 V and 20 V.

5.1    Draw the circuit diagram.

5.2    Calculate the minimum power for the Zener that could be used safely in this circuit.

5.3    Using a Zener diode with a power rating of twice this minimum value.

5.4    Calculate the range of series resistance that may safely be used in this circuit and suggested a suitable standard resistance value.

Question 6  (IEIIQ19)

A voltage regulator is required to provide a regulated terminal voltage of 25 V at a maximum load of 150 mA. The input volage varies between 50 V and 75 V dc.

6.1    Calculate the minimum power for the Zener that could be used safely in this circuit.

6.2    If a 30 W rated Zener is used, calculate the range of possible series resistance, RS. values and suggest a suitable standard E12 resistor value.

Question 1

A simple Zener diode shunt voltage regulator is to supply 12 V to a load which normally draws a load current which varies from 0 to 50 mA. The input voltage varies between 15 V and 18 V.

1.1 Calculate the maximum rated current value of a Zener device to be used.

1.2 Calculate the minimum power for the Zener that could be used safely.

1.3 If a 5 W rated Zener were to be used, calculate the range of possible RS. values and hence suggest a suitable standard E12 resistor value.

1.4 State four (4) conditions under which a Zener diode dissipates minimum power in a regulator circuit.

Question 2 (IEIIQ15)

A 2.5 W Zener diode is used in a simple Zener shunt voltage-regulator to supply 5.1 V to a load which normally draws a load current varying from 0 to 125 mA. The input voltage varies between 8 V and 9.5 V

2.1 Give two (2) reasons for the inclusion of the series resistor in the Zener-regulator circuit.

2.2 Calculate the range of series resistance that may safely be used in this circuit.

2.3 Select a single suitable standard E12 resistor value and give its colour code with 1 % tolerance.