Quantcast
Channel: Question and Answer » voltage-divider
Viewing all articles
Browse latest Browse all 30

How does the resistance of the load affects a voltage divider?

$
0
0

Every explanation I’ve seen so far about voltage dividers, only consider the two main resistors (that do the “dividing”), and pretty much ignore what happens after Vout.

The circuits in the explanations look more of less like this:

Vanilla Voltage Divider

In this example the voltage at Vout should be 2.5V.

This really gives the impression, that whatever goes on for the rest of the circuit, Vout is at 2.5V.

But what happens in practice, if I get something connected to Vout? E.g, I connect some components, and their equivalent resistance is 100Ω:

Voltage Divider with load

Since R2 and R4 are in parallel, an equivalent resistor would be of 50Ω. Now, if that’s correct, then the voltage divider really operates between a 100Ω and a 50Ω resistor. I.e. the voltage at Vout would be 1.67V and not 2.5V, as I originally wanted it to be.

Is this really how it works?

How should one design the part that connect to Vout to avoid messing up the divider?


Viewing all articles
Browse latest Browse all 30

Trending Articles