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Powering Propeller Mini — Parallax Forums

Powering Propeller Mini

Mag748Mag748 Posts: 266
edited 2015-06-19 16:56 in Propeller 1
I'd like to power my Propeller mini from either USB Bus power (+5V) and/or an external battery. Is this wiring appropriate?

Mini Power.PNG


Thanks,
Marcus
Mini Power.PNG
976 x 1014 - 25K

Comments

  • kwinnkwinn Posts: 8,697
    edited 2015-06-19 09:48
    Should be fine as long as the battery voltage is a bit more than +5V.
  • Mag748Mag748 Posts: 266
    edited 2015-06-19 09:51
    Hey kwinn,

    What are the potential issues when the USB connection is established, but the battery is disconnected? In that instance, 5V will be on the output of the VReg. Is this a bad idea?

    Thanks,
    Marcus
  • LeonLeon Posts: 7,620
    edited 2015-06-19 10:24
    Check the regulator data sheet.
  • kwinnkwinn Posts: 8,697
    edited 2015-06-19 10:31
    Not a problem with the battery disconnected. With the battery in the diode in the schematic you posted needs to be between the USB +5v supply and the mini or you may have trouble.
  • Mag748Mag748 Posts: 266
    edited 2015-06-19 11:27
    Kwinn,

    The "+5V" in the schematic is the USB 5V.

    Leon,

    The datasheet provides a functional block diagram. But doesn't provide any additional information regarding a positive voltage from VOut relative to Vin.

    VReg Block Diagram.PNG


    Thanks,
    Marcus
    VReg Block Diagram.PNG
    752 x 454 - 29K
  • kwinnkwinn Posts: 8,697
    edited 2015-06-19 16:56
    Re: "The "+5V" in the schematic is the USB 5V."

    That's good. The diode will block any possibility that connecting the battery while the USB interface is connected will damage it.
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