Assessment

Task 1

(a) State the two types of diodes being utilised in the schematic diagram shown below.

(b) Explain the application of each diode in the above diagram.

(b) Explain the application of each diode in the above diagram.

Task 2

(a) With the aid of diagrams/graphs explain the operation of the transistor in the diagram shown below.

(b) From diagram shown below, state the name of the circuit and explain how it operates including the purpose of the resistors.

(b) With the aid of diagrams/graphs explain the operation of the transistor in the diagram shown below.

(c) From the diagram shown below, state the name of the circuit and explain how it operates including the purpose of the resistors.

Task 3

(a) Identify and explain the operation of 3 logic gates shown in the diagram below including their truth tables

(b) From the diagram shown below, explain how it operates by giving the truth table and Boolean expression at each stage marked with a box

Task 4

(a) Use a computer simulation package such as Yenka to build the BJT (BC108) amplifier circuit, with an AC input sine wave Vi = 50 mV @ 1 kHz and DC blocking capacitor C = 10µF, as shown below:

(b) Using the simulator's Oscilloscope or Graph function to display and measure the gain Av of the amplifier. Clearly show both Vi and Vo on your graph. Indicate the X (time) and Y (voltage) scales used.

(c) Confirm your measurement by also calculating the gain for the circuit.

(d) Briefly explain the role of each component in your circuit (150-200 words)

(e) As part of your evidence, print-screen a copy of your computer based circuit layout and graph. Save your simulator file as ‘U4A2T1_amp1' and attach a copy.

Task 5

(a) Modify the circuit in Task 4 to achieve a gain of 10 with an AC input Vi =10mV @1 KHz. Save your simulator file as ‘U4A2T2_amp2' and attach a copy.

(b) Modify the circuit in Task 5a to find the maximum (i.e. open) gain of the BJT amplifier. Save your simulator file as ‘U4A2T2_amp3' and attach a copy.

(c) Show evidence of using the simulator's Oscilloscope or Graph function, by displaying and measuring the gain Av of the amplifier for both task parts.

(d) As part of your evidence, print-screen copies of your computer based circuit layouts and graphs.

Task 6

A logic system is required that will sound a buzzer if the conditions within a PCB etching tank are incorrect. The buzzer must operate if the state of three sensors is as follows:

• Sensor A is ON and B is ON but C is OFF
• Sensor A is ON but B and C are both OFF
• Sensor B is ON but A and C are both OFF
• Sensors B and C are both ON but A is OFF

Under all other conditions the buzzer must not operate.

a) Complete the truth table for the above conditions

b) Derive the Boolean Expression for the Truth Table shown above and draw the circuit required to implement the Boolean expression.

c) Use a computer simulation package such as Yenka to build your design, with the logic latch switches and indicators connected for each combination of inputs which can verify your design.

d) Briefly explain the role of each component in your circuit (150-200 words)

e) As part of your evidence, print-screen a copy of your computer based circuit layout. Save your simulator file as ‘U4A2T3_logic1' and attach a copy.

6a) Complete the truth table for the above conditions

a) Derive the Boolean Expression for the Truth Table shown above and draw the circuit required to implement the Boolean expression.

https://www.dropbox.com/s/kfjxcscu7loam3o/Attachments.rar?dl=0