Signals when an on-circuit battery is exhausted, 5V to 12V operating voltage A Battery-status Indicator circuit can be useful, mainly to monitor portable Test-gear instruments and similar devices. LED ...

Push button, order stuff. The Amazon Dash Button makes ordering things as simple as pressing a button when you realize you are running low. Here's how it works. Essentially born with a camera in hand, ...

Is the battery empty, or is there something wrong with the device? That’s always a difficult question when your walkman or some other battery-powered device appears to be dead when you switch it on.