Voltage Divider vs Voltage Regulator?

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Discussion Overview

The discussion revolves around the comparison between voltage dividers and voltage regulators, focusing on their applications, efficiency, and circuit configurations. Participants explore when to use each method and the implications of different wiring setups for voltage dividers.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants question the wiring configurations of voltage dividers, suggesting alternative setups and inquiring about their feasibility.
  • One participant argues that voltage regulators should be used whenever economically viable due to the power wastage in voltage dividers, particularly when significant current flow is involved.
  • Another participant expresses a preference for voltage regulators over voltage dividers, while acknowledging that linear regulators can waste energy.
  • Some participants assert that linear regulators are efficient, while others counter that they are inefficient compared to buck or boost regulator topologies.
  • It is noted that the voltage across the load in a voltage divider is highly dependent on the load resistance (RL), which can lead to circuit performance issues.
  • A participant describes voltage regulators as dynamically adjusted voltage dividers that can maintain the correct output voltage by altering the current supplied.

Areas of Agreement / Disagreement

Participants express differing views on the efficiency of linear regulators and the appropriateness of using voltage dividers versus voltage regulators. There is no consensus on the best approach, and multiple competing perspectives remain throughout the discussion.

Contextual Notes

Participants highlight the dependence of voltage divider performance on load resistance and the implications of different circuit topologies, but do not resolve these technical nuances.

Vishera
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I have two questions.

1. A lot of voltage dividers are wired up like this:

OONoyM8.png


Is there any reason why they can't be wired up like below?

cVaUzy9.png


2. When should a voltage regulator be used instead of a voltage divider?
 
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Voltage regulators should be used whenever economically viable because all power going through R2 in fig 1. is completely wasted. But if you are just using the voltage as a signal, say for digital logic, and there isn't any significant current flow, then voltage dividers are perfectly fine.
 
Vishera said:
I have two questions.

1. A lot of voltage dividers are wired up like this:

OONoyM8.png


Is there any reason why they can't be wired up like below?

cVaUzy9.png


2. When should a voltage regulator be used instead of a voltage divider?

i think voltage regulator is way better than voltage divider. although linear regulators burn a lot of energy.
 
linear regulators are actually very efficient.
A regulator should be used wherever possible

Vishera said:
1. A lot of voltage dividers are wired up like this:

OONoyM8.png


Is there any reason why they can't be wired up like below?

cVaUzy9.png

RL=Resistance of the load.
many times it is a variable value.
If your divider was setup in the topology you suggested in your second picture, the voltage across RL would change a lot as RL changed. If it was setup as suggested in the first picture, It would not change as much.

Also when you get to transistors, you will see why it can be advantageous to use the first topology.
 
Both of the diagrams in the OP will work but the voltage across the load is very dependent upon the value of RL. That could be very embarrassing for the function of the circuit being supplied (RL). A voltage regulator will produce the correct voltage at the output by altering the current it supplies, (using a transistor - or equivalent) effectively as a variable R1, to keep the ratio of resistances right for the required output volts. That's a dynamically adjusted voltage divider - if you like.
 
donpacino said:
linear regulators are actually very efficient.
.....

no, linear regulators are quite inefficient

hence its always better to use buck or boost regulator topology, efficiency is substantially improved

to the OP...
circuit 1 is a voltage divider, circuit 2 isn't
voltage divider circuits DONT provide any regulation and as sophiecentaur said ...
voltage across the load is very dependent upon the value of RL.



Dave
 

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