With a 10 volt input source that gets stepped down to 5 volts with an LM7805, you’ll end up wasting 5 watts and only getting 50% efficiency from your efforts. Let’s compare two different voltage regulation situations to see how a linear regulator stacks up: This is why linear voltage regulators are ideally suited for applications where power requirements are low, and the difference between input and output voltages is minimal. Because it behaves like a resistor to stabilize voltage, it ends up wasting a ton of energy as it converts resisted current into heat. The downside to this type of regulator ultimately comes down to how it functions. The LM705 wired in series to provide a stable output voltage. For example, a 3-pin linear voltage regulator like the LM7805 provides a consistent, 5 volt 1 amp output so long as the input voltage doesn’t exceed 36 volts. Regardless of what kind of load is placed on your circuit, a linear voltage regulator will always keep pace to provide you with a constant, steady output voltage. With the linear regulator, you’ll be taking advantage of a power transistor (BJT or MOSFET) that plays the role of a variable resistor, raising and lowering the output voltage of your circuit as your input supply changes. This type of regulator acts as a voltage divider on your circuit and is the kind of regulator commonly used when you’re designing low power and low-cost applications. When it comes to adding a voltage regulator to your circuit, you’ll typically work with one of two types – Linear Voltage Regulators or Switching Voltage Regulators. The last thing you want is to fry your microcontroller because it couldn’t handle a spike in voltage.

Secondary : Voltage regulators also work to shield and protect your electronic circuitry from any potential damage.

You might have 9V in, but if you only want 5V out, then you’ll need to step it down (Buck) with a voltage regulator. Primary: To generate a steady output voltage of a circuit in response to variations in an input voltage conditions. At the end of the day though, every voltage regulator has a primary and secondary goal: Some voltage can be controlled by a simpler Zener diode, while other applications require an advanced topology of linear or switching regulators.

How a voltage regulator achieves this task is ultimately up to the designer. The LM7805 is one of the most popular linear voltage regulators around.

Variable voltage regulator circuit