I have an audio device with 8 channels, every 2 of which need to be powered by a 5V power outlet. Up until now, my lab used USB chargers to solve the problem.
But now I have to improve upon it, and I want to make sure I keep to best practices.
Each device powers 2 vibrating actuators with 5V USB cables. Instead of connecting them to a splitter, I'd like to place all 3 power lines on a singular breadboard, and connect them all to a single USB, like so:

 *    *    *    *    *    *    *    *    *    * -   *
 *    *    *    *    *    *    *    *    *    * -   *
 *    *    * D1pwr     D2pwr     D3pwr   *    *    USBPWR
 *    *    * D1gnd     D2gnd     D3gnd   *    *    USBGND
 *    *    *    *    *    *    *    *    *    * -   *

Is this the safe way to connect them all? Or would you have a better idea?

  • \$\begingroup\$ What's the maximum power each of your devices requires? I fear 8 times that could be more than a single USB port can provide. \$\endgroup\$
    – PMF
    Feb 19 at 7:34
  • \$\begingroup\$ every device needs a 5v power source, and I need 3 devices \$\endgroup\$ Feb 19 at 7:40
  • 1
    \$\begingroup\$ The question is power (Watts), how much power or current do the devices need at 5V? \$\endgroup\$
    – Mat
    Feb 19 at 7:43
  • \$\begingroup\$ Should be between 1.5W- 2W each actuator. a single device consists of 2 of them \$\endgroup\$ Feb 19 at 8:10
  • \$\begingroup\$ "I want to make sure I keep to best practices" Best practice #1: never use breadboards for anything, particularly not for high current signals. You need a proper supply and properly isolated connectors everywhere. \$\endgroup\$
    – Lundin
    Feb 19 at 9:42

1 Answer 1


You have 2W x 2 actuators x 8 devices = 32W. The maximum you can reasonably get out of a single USB port at 5V is 15W, most chargers can even only deliver 10W or less. So that's not going to work. Additionally, voltage drop will be significant if you draw that much power out of an ordinary USB cable. Since you apparently only need the 5V power and no data lines, I would suggest to use a lab power supply instead. These can more easily deliver the required current (you need roughly 7A to be on the safe side) and also use adequate cables for that.

  • \$\begingroup\$ Isn't that rather 8 channels in 4 pairs? So 2W * 8 = 16W. Either way, too much current for USB and breadboards. \$\endgroup\$
    – Lundin
    Feb 19 at 9:40

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

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