DC circuit calculation formula - Solutions - Huaqiang Electronic Network

Ohm's law

1. Passive branch:
Where: U---- branch voltage (V)
------I----branch current (A)
------R----branch resistance (Ω)
------±---U and I take the + sign in the same direction, otherwise take the - map A , Figure B

Ohm's law 2, active branch
Where: E----branch electromotive force (V) U, I, R and passive branch
-----±U and I, E and I take the + sign in the same direction, otherwise take the first picture A . Figure B Ohm's law 3, full circuit
Where: E1, E2--loop electromotive force (V)
------I-------loop current (A)
------ΣR-----the sum of loop electrons (Ω)
------±------E1, E2 and I are taken in the same direction + otherwise take the - sign
Conductor resistance (Ω) Where: R---conductor DC resistance (Ω)
------ι--conductor length (M)
------S---conductor area (CM )
------ρ--conductor resistivity (Ω.CM /M) Conductor resistance and temperature (Ω)
In the formula: ---The resistance at the conductor t °C (Ω)
------ ---The resistance of the conductor at 20 ° C (Ω)
-------a----The temperature coefficient of resistance of the conductor (1/°C)
-------t----temperature (°C) conductance and conductivity

Where: G---conductance (S)
------ ---Conductivity (A)
------ ---Resistivity (S)

Work

rate

Where: P--power (W)
------U--voltage (V)
------I--current (A)
------R--resistance (Ω
When I is constant (resistance series), P is proportional to R
When U is constant (resistance is connected in parallel), P and R are inversely proportional to the resistance string,
and,
Complex connection: resistance: Conductance: when =0, the voltage on R2 Where: Uab--ab terminal voltage --Partial pressure ratio Resistance string,
and,
Complex Parallel resistance: Conductance: when When =00, the divided current on R2: Where: Iab---terminal current flowing through ab Split ratio Resistance string,
and,
Complex Double coupling resistance: Conductance: Capacitor string, parallel, complex Concatenation: When n coherent C0s are connected in series When C3 is short-circuited, the voltage on C2 Where: Uab----ab terminal voltage Capacitance divider ratio Capacitor string, parallel, parallel connection:
When n identical COs are connected in parallel, C=nco Capacitor string, parallel, parallel connection:
When n identical COs are connected in parallel, C=nco Shield coil series, parallel equivalent inductance series Shield coil series, parallel equivalent inductance in parallel Battery string, parallel Series E=E1+E2+En ------I=I1+I2+In
R1 and r2 are the internal resistance of the battery respectively. When the electromotive force of the n batteries is E0, the internal resistance is r0. Battery string, parallel Tandem R1 and r2 are the internal resistance of the battery, respectively. The electromotive force and internal resistance of each battery must be equal to be parallel, otherwise current will be generated between the batteries, consuming energy. DC circuit calculation formula