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I am trying to build a linear 24/12V power supply. One of the requirement for it is for the line regulation to be very precise (an error of 0.0005 V is considered acceptable). I wanted to use a linear regulator Ic, but I haven't found any that fit my needs.
What can I use to build such a supply?
Thanks!
From what you're saying, it sounds like you want to do this from ac wall power? Please clarify. Although you say you want to use a linear voltage regulator, I would caution against that. It may be better to combine a transformer, a full bridge rectifier, and a switching power buck (or boost) power supply that meets your quality requirements.
Linear voltage regulators will have ripple, and because many things don't use them anymore, they aren't subject to the kind of innovation that switching supplies get. Linear power supplies remove power as heat. This can be calculated by the equation (Vin - Vout) * I = Heat (in Watts). It is because of this wasted power that most higher voltage things don't use linear supplies. Of course, arduino boards use them because the draw very low current, and it much less space consuming.
If your goal is less supplying power and more a precise voltage, consider a precision voltage reference. These can be as cheap as $5 if you're willing to buy from china.
In conclusion:
Linear power supplies step down voltage with considerable ripple based on many factors, like supply voltage, and also produce heat
This heat makes them a poor choice for situations requiring high voltage, long battery life, or both.
A switch mode power supply may be good if you can find one with that precision if you still want efficiency
Also, consider a precision voltage reference if you need very high precision.
