Simple circuits
- Notes
-
Parallel resistors
- ΔV MUST be same for all
- To reduce: Req = 1/(1/R1 + 1/R2 + ...)
- NOTE: Req < smallest of R1, R2, ...
- To un-reduce: all ΔVs are same as Req ΔV. I's are unknown.
-
Series resistors
- I MUST be the same for all
- To reduce: Req = R1 + R2 + ...
- To un-reduce: All I's are the same as Req. ΔVs are unknown.
- Lab instructions: For each circuit
- ΔV = 1.5V, R1 = 0.1kΩ, R2 = 0.22kΩ, R3 = 0.33kΩ, R4 = 0.1kΩ, R5 = 0.22kΩ
-
1 - perform one reduction at a time, redraw the reduced circuit, fill in all information you know and leave blanks for information you don't know, keep reducing until circuit is power supply and one resistor, solve for Itotal, then work backwards by un-reducing until you find the desired ΔV.
-
2 - build the circuit using either cables and clamps, or a breadboard.
-
3 - get me: I will test your circuit and prediction.
- You must compute / build circuits in order (7, 8, 9, 10)
- Grade is determined by the last circuit you successfuly compute and build (80, 85, 90, 100)
-
Notes to me:
-
6: I = 02.3mA, ΔV2 = 0.508V
-
7: I4 = ΔV / (100Ω + 330Ω) = 03.5mA
ΔV4 = 03.5mA × 1000Ω = 0.35V
-
8: Req = 466Ω, I = 03.2mA
ΔV3 and 4 = 1.5V - I ×(200Ω) = 0.47V
I3 and 4 = 0.47V / 430Ω = 01.1mA
ΔV3 = 01.1mA × 330Ω = 0.36V
-
9: R45 = 68.8Ω, R345 = 398.8Ω, R2345 = 141.8Ω
Req = 241.8Ω
I1 = 06.2mA
ΔV2 = 1.5V - 06.2mA×100Ω = 0.880V
I3 = 0.880V / 398.8Ω = 02.2mA
ΔV3 = 02.2mA × 330Ω = 0.728V
-
10: