All items tagged with Power and Alarm (3)

| This small circuit beeps for a couple of seconds when the AC power supply fails or drops out. For the power supply (PSU) we’ll use a small 5...

| It’s often little things that make outdoor living more amenable. This circuit makes it presence felt vociferously when the fixed electricity...

| Smoke alarms are extremely useful devices, but they suffer from one significant disadvantage, which is that they’re battery powered. This ci...