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Columbia
ISA Theater Basics |
REMOTE CONTROL
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With most pieces of consumer electronics, from camcorders to stereo equipment, an infrared remote control is usually included. Video and audio apparatus, computers and also lighting installations nowadays often operate on infra-red remote control. The carrier frequency of such infra-red signals is typically in the order of around 36 kHz. The control codes are sent in serial format modulated to that 36 kHz carrier frequency (usually by turning the carrier on and off). There are many different coding systems in use, and generally different manufacturers use different codes and different data rates for transmission. "IR" stands for infrared. Infrared light is invisible since its frequency is below that of visible red. Otherwise, it is like any other light source, operating under the same laws of physics. In most cases, the IR signals are produced by an LED source. IR transmit and receive systems are inexpensive and are generally reliable. However, interference from other IR sources can be a minor issue. Interference can come from IR remote controls, IR audio systems (these broadcast an IR signal continuously) or other IR sources. Interference can also be caused by other light sources such as fluorescent lights (the ballast can cause IR interference). Sometimes some electronic ballasts powered light can cause interference problems. In order to avoid any interference with this kind of equipment, the operating frequency of all electronic ballasts has to be chosen so that problems in the 36 kHz frequency area are out of the question. Many existing IR systems modulate the IR light at around 36-40 kHz (this is the frequency of the IR carrier and should not to be confused with the actual frequency of the IR light itself). The possibility of interference is more likely around the 40 kHz frequency. One way to limit interference is to use higher IR carrier frequencies. Some IR systems now use carrier frequencies into the megahertz region.
Types of Remote Controls Standard Remote
Single-Brand Remote Universal Remote
Learning Remote Programmable Remote
Custom Remote
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