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# voltage dividers and regulators

***

## voltage dividers

#### *overview*

* a voltage divider is a circuit that is used to turn a large voltage into two smaller ones
* a voltage divider contains a power supply and two resistors (various types of resistors can be used for the two resistors)
* the resistors are used to create an output voltage that is a certain fraction of the input voltage ![](/files/LwPpV99l3OwGf7r6JGBI)

#### *applications of voltage dividers*

* **w/ variable resistor:** as you adjust the variable resistor, you change the ratio of resistance in the circuit, hence changing the output voltage.
  * ![](/files/zFBj8Mfr9nEycJGDfIY2)
* **w/ potentiometer:** as you adjust the potentiometer, you change the resistance between the middle and the outer terminals, hence changing the output voltage
  * ![](/files/ITckWZeesTpZsMFMKmk8)
* **w/ thermistor:** one resistor is a fixed value, and the other is the negative temperature coefficient (NTC) thermistor, meaning
  * when it’s a higher temperature, the thermistor's resistance decreases, hence inducing a higher output voltage. vice versa for lower temperature.
  * ![](/files/cqp8tx7fD2rULB4NF95R)
* **w/ photoresistor:** one resistor is a fixed value, and the other is the photoresistor, meaning .
  * when the light intensity is greater, the photoresistor's resistance decreases. hence inducing a higher output voltage. vice versa for lower light intensity.
  * ![](/files/CuvDrwWqCEc9La1kgQwm)

## voltage regulators

#### *overview*

* voltage regulators are a type of integrated circuit designed to maintain a constant voltage.
* they convert varying input voltages into fixed output voltages.
* a voltage regulator has two main functions:
  * to take a higher input voltage and release a lower output voltage that is more suitable for the components in the circuit.
  * to protect from potential voltage surges that could damage components in the circuit.
* ![](/files/CiAp6fbYGso1Wd34UC9H)

#### *power supply smoothing*

* power supply voltages can sometimes be erratic, and this could potentially damage the electronic components they are connected to.
* to solve this issue, capacitors are typically included to reduce the fluctuations to a level that most devices can easily handle.
* they do this by charging themselves when the voltage levels are high, and then discharging themselves when the voltage levels become low.
* [example datasheet](https://www.ti.com/lit/an/slta055/slta055.pdf)