Bluetooth Speaker Powered with Benchtop Supply
With this simple hack, Mike Szczys was able to bring a dead speaker back to life.
Mike Szczys has a battery-powered speaker setup that sounded great when connected to a Chromecast audio via a line-in jack. It’s meant to run on lithium batteries, and while it has a USB connector for recharging, this isn’t powerful enough to actually supply the speakers continuously when plugged in. Thus the batteries eventually wore down until the device no longer worked.
Naturally, Szczys decided to fix it… two years ago, and now that he’s cleaning up his workshop, he pulled it out of the "future project" bin to execute the repair. Since it would take some effort to bypass the voltage protection circuit, he clipped the battery leads and powered it up with his benchtop supply at 7.4V with 1.5A of current. This worked quite well, but he didn’t have a proper wall wart available for the task. Instead of ordering something or trying another hacky solution he chose to use the benchtop supply as a permanent setup.
To do this, he disconnected the original USB charging port, and added a pair of banana sockets for easy hookup. Since the speaker will be used in the shop, this seems like a very practicable solution, though he may need to turn the tunes off when working from time to time to power other devices. On the other hand, it should be neat to see the current change with volume levels, as as sort of very rudimentary VU meter!