Node voltage ,Mesh current, Thevian and Norton

current always flows from

high to low potential

Choose reference node as

the one with the most connections

current if possible should flow too

the reference node

Always write node voltage in terms of off

Highest to lowest potential (decided by current)

What is a super node

2 nodes constrained by a voltage source

How do you pick how to write a supernode constraint equation (e.g., V2- V1 = 12 )

The node facing the positive has a higher potential

What do you do if there is only a voltage source between a node and the reference node

Assign the voltage to that node

What do you always do for resistors in a mesh current or KVL loop

assume that their polarity is in accordance with the current direction making them always positive

if you have a current constrained in 2 loops how do you create the constraint eqaution

The one that is in the same direction as the current takes precedence

Does the direction in which you pick your currents matter

No

unless they move in the same direction, which current always takes precedence

The one in the mesh you are currently analyzing

If there is a current source acting on only one source, what do you do

Use its value and assume its direction for your mesh current

When should you rather use the node voltage method

When there are more current sources

When should you rather use MCM

When there is more voltage sources

What is the Thevian voltage

represents all the voltage and current sources of the circuit

what is thevian resistance

represents all other resistors as a single value excluding the load

What is the load

the resistor you are investigating

How do you calculate the VTH for independent sources only

Remove the load and calculate the voltage between the 2 terminals

How do we calculate RTH for independent sources only

Short-circuit all voltages

Open circuit: all current sources

Then look into where the load used to be and calculate the total resistance of the circuit

VTH for independent and dependent

remove load and calculate Voc between the terminals

RTH for dependent and independent

Because we cannot remove independent and dependent sources, we create a short circuit between the terminals where the load used to be.

We can then calculate the current flowing through this and hence calculate R using V = I x R

Dependent sources only

Can't calculate Vth because there is no flow of electricity because of no independent sources

Therefore, remove the load and put a 1ma current between the terminals

For dependent sources only, why do we already know our ISC

because it is the 1mA current we have placed in

When is thevian more useful than other analysis methods

When you want to exchange different values from your circuit as the load

How do the components of a Norton equaivalent circut compare to one another

They are all connected in parallel with one another

what is NC

current that represents all the voltages and currents in the circuit

what is NR

same as RTh

How do calculate NC Independent sources

Replace the load with a short circuit and calculate Isc

How do you calculate NR independent sources

same as RTh

how do you calculate NC independent and dependent sources

Replace the load with a short circuit and calculate Isc

How do you calculate NR in dependent and dependent sources

Remove load /short circuit and calculate open circuit voltage, then use RN = Voc/Isc

How do you calculate NC and RC for dependent sources only

Same as thevian

How do you decide direction of Isc

you should use passive convention that it flows from highest to lowest potential.

(essentially flowing to the reference node )

Can you do a big KVL loop using mesh current values?

yes