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Integrated Circuits
Integrated circuits (“ICs”) are single packages that contain complete circuits consisting of many components. Today almost all ICs are silicon chips. Intel claims to have produced single ICs with 2,000,000,000 transistors.
For the last experiment we are going to use a “4017” decade counter. When this is driven from the output of a multivibrator it can be used to light LEDs in sequence producing a chain light effect.
Much of modern electronics is based on using ICs rather than discreet components. The skill lies in finding the right IC and understanding how to use it and its limitations. For example it's unusual to build multivibrators like the ones in these experiments in most designs – instead a timer IC like the famous “555” might be used.
Note about IC Numbering
Numbering of ICs a pretty hit and miss. The “4017” is just the base name for the device. The full number will have other numbers or letters attached depending on which company makes it, what type of package it's put in and so on. You will often find lots of variants of the same IC with similar numbers. The IC in my parts kit says it's an “CD4017BE”.
Gordon Earle Moore
(3 January 1929-)
Observed that the capacity of economically feasible ICs doubles approximately every 2 years.