Using Kirchoff's Voltage Law to your advantage

[Richardcavell]

Hi.  I have been wondering whether it is possible to use KVL in this way:

If I have a series circuit where there are a number of components in series, but the voltage drops are difficult to calculate, or variable, and I want to ensure what the voltage is at a certain node (perhaps to make sure that there is a certain voltage available at a part of a circuit), I could place at least two resistors parallel to this circuit as a voltage divider.

I've drawn what I mean.  Select A and B to ensure an adequate supply to the bottom two components.

Richard

[WattsThat]

Let’s discuss the actual problem you’re attempting to solve, not your proposed solution

Voltage dividers are not power supplies. You reference/measure that voltage, not supply current to a device/circuit with that series chain. To supply current, you only need a single resistor, not a divider chain.
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[PlainName]

I could place at least two resistors parallel to this circuit as a voltage divider.

I've drawn what I mean.  Select A and B to ensure an adequate supply to the bottom two components.

The 'any components' will introduce a load in parallel to the resistors. Think of those 'any components' as simple resistors and you can see you can easily affect the junction voltage but changing one or more of the 'any components' apparent resistance. You will have two parallel strings of series resistors.

If they are not simple resistors - for instance, LEDs or any component with varying current requirement - then it gets quite complex, but that makes it even simpler to see that your idea won't work

[SteveThackery]

Apparently you want to control the voltage at the mid-point (the junction of A and B) by choosing appropriate values for resistors A and B? For example, making them equal would set the mid-point voltage to 2.5V - is that the idea?

It will only work if there is no current to or from the other half of the circuit (the four 'other components').  And the only time that will happen is when the mid-point is already at 2.5V.

Any current flowing in that horizontal wire - leftwards or rightwards - will alter the voltage at the junction of A and B away from what you calculated.

You need to think about what you are trying to achieve, and then come back to us with questions about how to achieve it.