Ramsey Electronics ICI1 Assembly And Instruction Manual - page 4
ICI1 Page 4
ICI1 INTRODUCTION
Welcome to the ICI1 kit (and if you don’t have the time, the wired and tested
version). We will make an attempt at helping you understand IR remote controls
and how they typically work, and also how this kit works to help you understand
what you are building.
Virtually any modern day consumer audio or video device contains an infrared
remote control unit. Usually our living room contains several of these to control
several different pieces of equipment. In fact we often have so many of these
little gems that it becomes necessary to obtain an “all in one” remote control
that controls all the functions of your entertainment system. Of course, this
leads to having several remote control units delegated to the junk drawer, and
that brought about the idea for this kit. Let’s put the old remotes to use
controlling an easy to build kit that will control four separate outputs. By toggling
a relay for each, we can live the life of the future by remotely controlling our
fans, lamps, and even the coffee pot!
Let’s dig into these units a little bit. A typical infrared
remote contains a few functional parts in common
with each other; we’ll examine them. First there is
some type of keypad assembly. Nowadays this is
typically a large molded sheet of rubber with the
buttons protruding outward. The end of the button you
cannot see is typically coated with a carbon “button”
that will make contact with the printed circuit board
underneath, completing the circuit when the button is depressed (no, it’ not sad,
it is just making contact!). This switch closure will cause an Integrated Circuit on
the circuit board to repeat a pre-determined code at the output. This digital
signal typically drives an infrared diode to conduct on the front of the unit
“broadcasting” the infrared signal to the equipment to be controlled.
Our eyes are sensitive detectors in the visible light range, but the wavelength
of the infrared diode falls outside that detection range. So we can’t see the
diode performing its function. But rest assured, given a fresh battery, it is
dutifully doing it over and over again. These codes are unique so that the
infrared detector on the equipment can determine what function each of the
buttons should be, and perform that operation. These controlling codes are
unique to each manufacturer, so our kit needs to “learn” these codes to perform
the functions we require.