A recent KXAN news report featured the story of a Round Rock couple who built their home specifically for energy efficiency. Beginning with a strong metal roof designed to support the weight of solar panels, they installed 24 panels which generate ample amounts of electric current.

In winter months, their electric bills are very low. However, as spring and summer months bring greater levels of heat and sunlight, their electricity bills fall into a negative zone. That’s because their photovoltaic panels are producing more electricity than their home consumes. To further reduce electrical consumption, the couple has replaced many incandescent lights with solid state lighting. Special skylights called “solar tubes” provide bright interior lighting during daylight hours, making their home even more efficient. Efficient foam insulation and a roof design which provides longer overhangs shades the walls and further reduces the electricity needed for cooling the home. In addition to this, their home’s heating and cooling unit uses a geothermal well. For more information, click on this web link: News Link

When the detector senses an object across its field of view move, it triggers the lights to turn on. The lights would stay on from 1 to 20 minutes, depending on how you preset the timer. After the preset time, the detector automatically shuts the lights off unless there are further movements within its range.

The controller keeps on monitoring the application requirement in a continuous control loop. It then commands the inverter to produce the required voltage and frequency to meet the application requirements. To do this, the controller, comprised of a microprocessor, takes the input signal from the sensor and compares this with a reference signal. It then generates the appropriate control signal for the inverter to vary its output power.

In a typical application, the controller will monitor process parameters such as pressure, flow rate, temperature or liquid level. For example, an oxygen sensor in a boiler provides a signal to adjust the speed of the fan and control the amount of oxygen in the boiler system.

Today’s drives, using microprocessors, semiconductor power switches, and SMDs are now smaller, compact, cheaper, more reliable and efficient. A typical drive will also include a filter to suppress harmonics generated when converting the DC to AC voltage.