The circuit operates using a pair of ultrasonic transmitter and receiver modules which are used to detect the person. When the person is detected (the person is in the front door), the doorbell is ...

AUSTIN, Texas — Christopher Bell is making the most of his late-race chances to seize victories. Bell passed Kyle Busch with five laps to go, then held off Daytona 500 winner William Byron to win ...

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 ...

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, ...