Regulators used in Embedded HardWare Designs
Regulators are mainly classified in to two- Linear Voltage regulator
- Switching regulators.
LINEAR VOLTAGE REGULATOR
They are good for powering very low powered devices.it is not advised to use in High end applications Since it is regulating the voltage by taking the difference between the input and output voltages, and just burning it as heat.
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| Linear Voltage Regulator -7805 |
The larger the difference between the input and output voltage/larger the output current ,Power dissipated will also be high .so it is recommender to use suitable Heat sinks according to the use.
Even the new LDO (low drop-out) regulators are also inefficient linear regulators - they just give you more flexibility with input voltage drops.
Power consumption is very important in embedded hardware boards. Due to this inefficiency of linear voltage regulators they are rarely used in High end applications.But still LDO is a better choice than a normal linear voltage regulator
Examples for Linear voltage regulators :
Low current fixed voltage regulators:
5V 1 A - 7805
12V 1A - 7812
Low current Variable voltage regulator:
3~28V 1A -LM317
For High current Variable Voltages
3~28V 5A - LM338
SWITCHING REGULATORS
A switching regulator works by taking small chunks of energy, bit by bit, from the input voltage source, and moving them to the output. This is accomplished with the help of an electrical switch and a controller which regulates the rate of switching . ie it controls the amount of energy transferred to the output.Switching regulators are complex circuits to design, and as a result they aren’t very popular with hobbyists.
The energy losses in Switching regulators is very small , which gives an efficiency of 80-95%. Since their efficiency is less dependent on input voltage, they can power useful loads from higher voltage sources.
Given below is Switching regulator which can be helpfull for hobbyists
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