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When do I use voltage regulators and voltage dividers?

Hardware design
March 11, 2021 by Jessica 2059

Let us assume that a 10 V battery is connected in series, and the resistance values of the two resistors are equal. According to the voltage division rule, the voltage between these resistors is 5V. I have a component (whatever it is) that needs to be powered on at 5 volts. When I try to use a 5V voltage value between these resistors to power them, the voltage division rule is interrupted, and my voltage on the component is less than 5 volts. I can't figure out how to provide it with 5 volts by using voltage division or basic circuit analysis techniques. What is the method to achieve any voltage value on any component?

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Samantha Posted on March 11, 2021

Voltage regulator is a fairly basic concept in electronic equipment. The simplest voltage regulator is linear (or sometimes LDO-low dropout). The regulator mainly uses two resistors to divide the voltage to generate the target output voltage (voltage divider). However, the regulator also monitors the output voltage, and when the output voltage changes (due to load changes), the regulator will change the resistor to compensate.

In a typical LDO device, the transistor is used as a variable resistor to adjust the voltage divider and achieve the desired output voltage.

There are other types of regulators that use different methods, but the common feature is that the device adjusts the output voltage to keep it as constant as possible, regardless of the load or input voltage.

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Ella Posted on March 11, 2021

It is correct for a 10V DC power supply, dividing it by 2 equal resistors will give you 5V. We see here:

This is because the current flowing through it will be 10 / 20k = 500uA. The voltage drop on the 10k resistor is: 500uA * 10k = 5V.


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Sarah Posted on March 11, 2021

So, what happens if you load something on this? let's see:



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