A dc power supply provides currents to four electronic circuits. The currents are 37 mA, 42 mA, 13 mA and 6.7 mA. The first two are measured with an accuracy of ± 3% and the other two are measured with ± 1% accuracy. Determine the maximum and minimum levels of the total supply currents.
To determine the maximum and minimum levels of the total supply currents, we need to calculate the individual maximum and minimum values for each circuit and then sum them up.
Let's start with the first two currents, which have a ± 3% accuracy:
1. Maximum current:
Maximum current = 37 mA + 3% of 37 mA
Maximum current = 37 mA + (3/100) * 37 mA
Maximum current = 37 mA + (0.03) * 37 mA
Maximum current = 37 mA + 1.11 mA
Maximum current = 38.11 mA
2. Minimum current:
Minimum current = 37 mA - 3% of 37 mA
Minimum current = 37 mA - (3/100) * 37 mA
Minimum current = 37 mA - (0.03) * 37 mA
Minimum current = 37 mA - 1.11 mA
Minimum current = 35.89 mA
Now let's move on to the other two currents, which have a ± 1% accuracy:
3. Maximum current:
Maximum current = 42 mA + 1% of 42 mA
Maximum current = 42 mA + (1/100) * 42 mA
Maximum current = 42 mA + (0.01) * 42 mA
Maximum current = 42 mA + 0.42 mA
Maximum current = 42.42 mA
4. Minimum current:
Minimum current = 42 mA - 1% of 42 mA
Minimum current = 42 mA - (1/100) * 42 mA
Minimum current = 42 mA - (0.01) * 42 mA
Minimum current = 42 mA - 0.42 mA
Minimum current = 41.58 mA
Now, let's calculate the maximum and minimum levels of the total supply currents by summing up all the individual currents:
- Maximum total supply current:
Maximum total supply current = Maximum current of circuit 1 + Maximum current of circuit 2 + Maximum current of circuit 3 + Maximum current of circuit 4
Maximum total supply current = 38.11 mA + 42.42 mA + 13 mA + 6.7 mA
Maximum total supply current = 100.23 mA
- Minimum total supply current:
Minimum total supply current = Minimum current of circuit 1 + Minimum current of circuit 2 + Minimum current of circuit 3 + Minimum current of circuit 4
Minimum total supply current = 35.89 mA + 41.58 mA + 13 mA + 6.7 mA
Minimum total supply current = 97.17 mA
Therefore, the maximum level of the total supply current is 100.23 mA, and the minimum level of the total supply current is 97.17 mA.