A Doorhandle Can Also Be A Garage Door Opener

As the name suggests a garage door opener is a device that is used to open and close garage doors. Generally the models are remote controlled.

Evolution

The initial garage door openers consisted of an actuator that could open or close the door. This actuator was controlled by a remote. The remote used was very simple and consisted of a transmitter and on the actuator side consisted of a receiver and associated electronics. The receiver would function for a change in amplitude. However they had a major draw back namely security. Anybody with a transmitter could open or close the garage door. There were many incidents of garage opening by neighbors accidentally when they were trying to open their own garages. The next change came with dip switches. These dip switches could use a total of 256 combinations. This was sufficient to overcome the problem of accidental opening of others garages, however the security issue was still not solved. Anybody with a radio frequency recorder could record the frequency when somebody opened his garage door and later used that frequency to open the garage.

Present day technology has overcome the security concern to a large extent by use of rolling frequency or sometimes called hopping code technology. In this every time a new frequency is used to open and close the door.

Mechanical Part

The mechanical part of the garage door opener is pretty simple. Mainly three types are used: chain drives, screw drives and belt drives. Chain drives are noisy but are the cheapest. Screw drives have a lead screw and nut system to open and close the door. They are a bit costly. The latest models use plastic liner on the tracks to reduce noise and increase the operation speed. Belt drives are the quietest and are comparatively costly. The mechanism also consists of a main spring that is the most important element of the system. Usually two types of springs are used linear expansion and torsional springs.

In the market two types of garage door openers are available namely jackshaft type and trolley type. Even though the jackshaft type occupies less space, the trolley type is more popular. This is because of safety; in the jackshaft type it is difficult to sense when a person or a pet is being crushed under the door.

Some modern systems have auto reverse in case of obstruction like a pet or a vehicle. The remotes generally operate up to a range of 150 feet. Also most systems have keypads that are installed outside the garage and can be used if the remote goes dead.

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Advantages of Having a Counter Top Microwave Oven

Counter top microwave oven choices offer you a way to make your home cooking just a bit faster. If you are one of those people trying to save time by finding ways to shorten your time spent at the kitchen cooking, then the ever reliable microwave should not be missing in your home.

The microwave oven has become one of the most innovative inventions in the 20th Century. It has become a permanent fixture in most homes today. You could find a few homes today not having this ingenious appliance in the kitchen or the dining room. The counter top microwave oven has given people the convenience of quick cooking.

Most people today live a very fast paced life. They would find their time a very valuable commodity. Cooking and preparing food can take up most of that time. It is time that they would rather spend on doing things that matter more.

That is why more and more people would prefer shorter time periods to make more effective use of their time. It is a good thing that the microwave oven has come into the picture just when more and more people seem to have a need for it.

The microwave oven has provided people with the opportunity to do their cooking more quickly. Microwave ovens have the ability to heat up food in minutes. This is because such ovens use microwaves I order to heat food.

They are radio waves that belong to the frequency range of about 2,500 megahertz. Radio waves in this frequency range have the interesting property of being easily absorbed by water, fats and sugars. As they are being absorbed, they are converted directly into heat. Microwaves in this frequency also have another interesting property- they are not absorbed by most plastics, glass or ceramics.

Microwave ovens cook or heat food from the inside out. This is due to the ability of the microwaves to penetrate the food and excite the fat and water molecules evenly, thereby heat is distributed equally throughout the cooked food. It is far more effective in cooking your food in less time than conventional cooking which relies on heat conduction to cook food.

And because of this convenience, counter top microwave ovens have become a necessity in most homes. People no longer have to spend so much time cooking food especially when they are on the go. With the counter top microwave oven, quick cooking convenience has suddenly become more appealing and essential.

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