Powering board using Adafruit MicroLipo USB Charger?

leka0024leka0024
edited April 2017 in Hardware
(apologize in advance if there's already a thread on this -- please merge if so)

Anyone powering Main Board (V3) with/without Daisy attached directly from USB (adapter)? I have one from Adafruit that shows "3.7V/4.2V" on the silkscreen of the board. Do the TI chips on the OpenBCI boards have voltage regulators built in, so that I could connect higher voltage than the battery to the boards directly?

Another question, there's a place on the charger board where you can short two traces together to boost the current it can provide up from 100mA to 500mA. Is 100mA plenty to power the Main Board + Daisy?

Thanks!

Comments

  • wjcroftwjcroft Mount Shasta, CA
    The board you refer to from Adafruit,


    does not supply an "isolated" DC power supply from the USB device it is plugged into. AND it is not intended as a power supply. It's circuit is setup as a battery charger. I would definitely not recommend using this, since the charging circuit on the board is going to get confused. And may momentarily output voltages outside the range of the regulators on the mainboard.

    The easiest and safest strategy is to stick with a battery power supply.

    If you are insistent on powering from USB, you may want to consider what is called a USB isolator. These are available in various gradations, including medical rated ones. These devices galvanically isolate the USB power lines from the output power lines. Which, in the case of the medically rated devices, provides up to 5K volts isolation from the input power source. This is a requirement for medical equipment meeting IEC 60601 standards of safety.


    However note, even with the isolators, there are gradations in how well filtered the 5V DC output is regulated, depending on the manufacturer's circuit. The cleanest DC will always be from a battery or from the output of a linear DC regulator chip.
  • leka0024leka0024
    Thanks for the reply. Makes sense to me!
Sign In or Register to comment.

© Vanilla Keystone Theme 2026