Electronics advice needed for the Eyedrivomatic project

Patrick Joyce wrote 09/25/2015 at 18:002 points

Hya. I have a problem that i would be grateful for some help with. 

Eyedrivomatic uses an arduino to control two servos. For the servo power i want to use a cheap usb battery pack, of the sort used for emergency charging of mobile phones. The arduino itself is powered through the usb cable (which is always connected). My problem is that the power packs automatically shut down when there is no drain, ie. when the servos aren't moving. They don't then turn back on  when the servos want to move again. Very irritating. I am currently using more expensive battery packs with physical on/off switches, but want to reduce the costs for other users. What i need is a way to fool the battery pack into staying on regardless of whether the servo is moving or not.

If my hands worked i would tinker with it until i found a solution, but they don't. I'm a quadraplegic, and have to rely on my carers for all physical tasks.