Information
Electrical Measurements and Electronic Instruments
Assignment 11
Question 1
Not answered
Marked out of 5.00
+15V +15V +15V
2.5kΩ 5kΩ
-15V
4kΩ 5kΩ
+15V
0.25mF 5kΩ
-15V
Consider the above circuit of an astable multivibrator using a 555 timer.
Peak-to-peak value of VC =? (in V)
Answer Range: 4.75 to 5.25
Solution:
VCC 2VCC
VC varies between 3
and 3
Correct answer is: 5
When VC is increasing then Vout is
a. High
b. Low
Answer: Low
Correct answer is: Low
Estimate the OFF (low) time of Vout (in seconds)
Answer Range: 1.07 to 1.183
Solution:
OFF time = (R1 + R2 )Cln(2) = 1.1263641684099 s
Correct answer is: 1.1263641684099
Estimate the ON (high) time of Vout (in seconds)
Answer Range: 0.6585 to 0.7278
Solution:
ON time = R2 Cln(2) = 0.69314718055995 s
Correct answer is: 0.69314718055995
Estimate the frequency of Vout (in Hz)
Answer Range: 0.5221 to 0.5771
Solution:
1
Frequency = ON time+OFF time
= 0.54959811081484 Hz
Correct answer is: 0.54959811081484
[0.5+0.5+1.5+1.5+1]
Question 2
Not answered
Marked out of 5.00
500μF
6kΩ
2kΩ +12V
+12V
4kΩ
-12V
-12V
Consider the above simple function generator circuit.
The waveform of V1 is
a. sinusoidal
b. square
c. triangular
Answer: triangular
Correct answer is: triangular
The waveform of V2 is
a. sinusoidal
b. square
c. triangular
Answer: triangular
Correct answer is: square
Estimate the peak-to-peak amplitude of V1 (in V)
Answer Range: 15.2 to 16.8
Solution:
4kΩ
The peak-to-peak amplitude of V1 = Hysteresis band of the non-inverting Schmitt trigger part = 212V × 6kΩ
Correct answer is: 16
Estimate the peak-to-peak amplitude of V2 (in V)
Answer Range: 22.8 to 25.2
Solution:
The peak-to-peak amplitude of V2 = 2 × 12V
Correct answer is: 24
Estimate the time-period of V1 (in milli-second)
Answer Range: 2533 to 2800
Solution:
12V
The slope or the rate of increase of V1 = R C
1
212VR2
R3 2R 1 R 2 C
The time required for V1 to go from the LTP to the UTP of the Schmitt trigger = 12V
= R3
R1 C
2R1 R2 C
Similarly, the time required for V1 to go from the UTP to the LTP of the Schmitt trigger is also = R3
4R 1 R 2 C
∴ The time period of V1 = R3
Correct answer is: 2666.6666666667
Estimate the time-period of V2 (in milli-second)
Answer Range: 2533 to 2800
Solution:
Time-period amplitude of V2 = Time-period amplitude of V1
Correct answer is: 2666.6666666667
[0.5+0.5+1+1+1+1 = 5 marks]