0
\$\begingroup\$

I need to power a string of 12v RGB LEDs, but they're controlled by a 3.3v micro controller (Wemos D1 mini)

As it's wearable (inside a hat) I need to minimize weight so don't want to need separate batteries to get the two voltages.

If I have a 12v Li-ion battery can I use a voltage divider to get 3.3v for the micro controller? Or is there a better solution?

\$\endgroup\$
  • 1
    \$\begingroup\$ Linear regulator. \$\endgroup\$ – user253751 Oct 1 '17 at 5:17
3
\$\begingroup\$

A linear regulator would be suitable for this application, provided that the microcontroller does not draw a significant amount of current, otherwise a heat sink will be needed.

This LD1117 can do the job.

\$\endgroup\$
0
\$\begingroup\$

A voltage divider will be a very bad design approach. Because the voltage level will vary depending on the load that you are planning to use (micro-controller in your case). So depending on the current drawn by the controller and also the state of IO pins the voltage will keep on varying.

If you are looking for some cheap options then 3.3V zener will also work (assuming you are not looking for tight regulation, which seems to be case in your case)

Else you can go for packaged IC's like LD1117 which has input voltage limit up to 15V. But you have to calculate potential maximum current drawn by the controller and hence heat dissipation across the regulator (you may have to use heatsink as well, which might defeat the purpose of using it on first place).

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.