These circuits were made using four very common voltage regulators - the LM7805, the LM2940, the LM1117 and the AMS1117.


The LM7805 is a linear voltage regulator that is very popular, because to put it to work no more components are needed.
It is a very inexpensive component.
Due to its characteristics, the way it reduces the output voltage is done at the expense of heat dissipation, which makes it inefficient.
In order for the LM7805 to work effectively, it must have a minimum input voltage of 7.3V.
It supports a maximum current of 1A. Some models support up to 1.5A.
It is advised to use capacitors and in some cases necessary to decrease / eliminate the effects of the frequencies introduced by the other elements of the circuit.
They also serve to mitigate the effects of peak consumption.


The LM2940 is from a different generation, while still maintaining pin compatibility with the LM7805.
It is a Low-dropout (LDO) Linear Regulator with better efficiency than the LM7805 although it will necessarily need capacitors.


The LM1117 has a different pinout than the previous two.


The AMS1117 in addition to being of a different format, maintains compatibility with the LM1117 in terms of pins.
It is a more recent integrated chip than the previous ones and with a superior efficiency.

ICFormatInputMax AmpDataSheets
LM7805TO-2207V a 20V1ALink
LM2940-5.0TO-2206V a 26V1ALink
LM1117TO-2206.5V a 15V800mALink
AMS1117-5.0SOT-2236.5V a 12V800mALink



Bill of materials (BOM)

  • All circuits need the following components in addition to the voltage regulator:

  • 2x 10uF 50V Electrolytic Capacitors

  • 1x 1k Ohm Resistor
  • 1x 3mm Led
  • 1x 9V Battery

IC Pin-out


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