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Powering FONA 3G w/ LM317
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Powering FONA 3G w/ LM317

by surpugs on Fri May 14, 2021 8:20 pm

Before reading further: lipoly batteries were out of the question due to flight restrictions on batteries to rural areas where flying is the only option for travel. These are extraordinary conditions that normal people don't encounter. Still try to use the battery if possible.

It's possible to power the FONA 3G without a battery with an LM317 voltage regulator which can handle the 2A spikes. I highly recommend that the heat sink is also properly utilized. However, in order to get around the regulator's voltage drop, it needs to be powered by something larger than the 5V commonly used for microcontrollers. In our case, we used 9V from a wall wart that also powered the microcontroller plus peripheries. Everything has worked fine since 2017 for 50+ research devices.

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Re: Powering FONA 3G w/ LM317

by adafruit_support_mike on Sat May 15, 2021 12:58 am

Thanks for posting the information.

It does sound like you have a special case where using a LiPo is out of the question. Glad to hear you found a solution thast worked!

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Please be positive and constructive with your questions and comments.