If you’re expecting an important visitor but you just have to step out for a moment, an electronic doorbell memory can come in handy so you can see whether someone rang while you were out. Of course, ...

A wired doorbell system has three components: a low-voltage (15- to 20-volt) transformer, a chime and a doorbell button. They are connected by 18- or 20-gauge low-voltage wires. Although it’s at low ...