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Chapter 2 Connecting Technology and Engineering through Mathematics and Science
27
Technology Explained
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Figure A. Smart-house systems
control energy use, security,
communications, lighting, and
entertainment.
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Figure B. A series of smart-
house controllers in a recently
built home.
Figure C. The wiring used in a
smart house is special. Three
types of cables are used:
applications, communications,
and hybrid branch. Convenience
centers are special outlets that
can be changed to meet the
needs of the homeowner.
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Cables
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Convenience center
Smart house: A house that allows computers to control
appliances and energy use.
Computer technology has been used to create an entirely new
type of house called a smart house. The smart-house system makes
home automation possible. This system allows the appliances and the
electrical, telephone, gas, and communication systems in a house to
interact. See Figure A.
The heart of a smart house is found in the system controllers.
See Figure B. These units serve as the hubs for messages between
products within the house. The system controllers constantly check the
system for problems. Electrical power, telephone service, and cable
television are brought into the house at a service center. A system
controller is installed there.
The smart-house system uses microprocessors and a unique
wiring system to allow the electrical appliances and products in a house
to interact. Participating companies are developing products with built-
in smart-house chips. These products can then interact with the system
controllers and the rest of the smart-house system.
Smart houses allow homeowners to change how their houses
work by programming the system controllers. Reprogramming a
switch changes what the switch controls. The heating system can be
programmed to vary the home’s temperature during the day. There can
be cool bedrooms at night and warm bathrooms in the morning. The
water heater can be set to turn on at a particular time so hot water is
available for morning showers. The electric range can be turned on to
cook a meal in the oven. The dishwasher can be set to start at night,
taking advantage of lower utility rates.
The wiring system in a smart house is unique. Smart houses use
three types of cables. See Figure C.Hybrid branch cables carry 120-volt
alternating current (ac) power and control signals. These cables provide
power for standard appliances, such as coffeemakers, digital videodisc
(DVD) players, and lamps. Communications cables carry audio, video,
telephone, and computer data signals. Applications cables carry 12-
volt direct current (dc) power and control signals. These cables provide
power for low-voltage devices, such as smoke detectors, security
systems, and switches. Large appliances, such as ovens and clothes
dryers, use conventional high-amperage wiring. Radio frequency and
infrared devices can be used to make a smart house wireless.
Smart House