What is the resistance dependent on the light?
Light -dependent light resistor is a semiconductor electrical device that has a very high power resistance, unless it is in the presence of light. If the light interferes with the device, it reduces its resistance, which allows to flow through electrical current and on other devices or electrical circuits. Due to this action, the light resistor is often used in any type of device that needs to be turned on or off, depending on the presence of light. Typical uses for bright resistors are street headlights and light meters used for photography. These types are said to be external. The light of dependent resistors can also be constructed from a single unpopulated material that has its own electric charge, such as silicon. It's called Intrinsic.
be it outer or internal, all light -dependent resistors work on the same basic principle. Electric chargeThey are not made of free electrons, but from electrons bound to the material matrix dependent on the light. This gives the device naturally high resistance to electricity. However, when the device hits, electrons bound in the material matrix are excited. If the light is strong enough, the electrons can be so enthusiastic that they can jump into the conductive zone of the device, allowing the electricity to be started.
The most inexpensive light -dependent resistors are designed with cadmium sulphide and serve a number of practical uses. In street heads, these devices save power by turning on light at dusk and at dawn. These types of devices are also used in photography lights; measuring measures measuring light -dependent resistor, which decreases with increasing light levels.
However, there are a number of other materials used in light -dependent resistors to change their properties and make them useful in applications that do not include visible light. SulphideAnd the lead antimonide Indium is used to create devices sensitive to some infrared frequencies, making them good infrared detectors. Copper Germania is another material that can make a light resistor so sensitive to far infrared light that some astronomers use it to create their observation.