Christmas Lights Sequencer Circuit using a 4017B

  
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Christmas is coming and its that time of the year again when the electronics student or hobbyists thoughts turn to making a Christmas circuit for their home and especially one that flashes a few lights. There are many circuits and kits on the market that can flash any number of lights periodically, randomly or sequentially but one very versatile I
Christmas Lights Sequencer Circuit using a 4017B - schematic

C that the hobbyist or student can use to produce a simple Christmas Lights Sequencer for use in a variety of different seasonal lighting displays is the CMOS 4017B Johnson Counter. The 4017B is a fast switching 5-stage Johnson decade counter complete with ten fully decoded outputs (making a total of 10 individual light sources). These ten outputs switch sequentially one at a time on the arrival of each new positive-going edge of the clock pulse. Only one output is at logic 1 ³ or HIGH  at any one moment while all others are cleared at logic 0 ³ or LOW , so it can produce a moving sequence or chaser effect, making the 4017 ideal as a sequential LED or lighting display for a Christmas lights project. The 4017B is basically a circulating shift register in which its serial outputs are connected back to its serial inputs in order to produce a particular sequence. The 4017B Johnson counter can also be used in frequency division applications as well as decade counter or decimal decode display applications. The 4017B is classified as counter because it exhibits a specified sequence of states upon the application of a clock signal or pulse. As the 4017B is used as a synchronous counter, the switching action of all the internal flip-flops are from the common clock signal as shown. But before we can use the 4017B Johnson counter as part of our Christmas lights sequencer circuit, we need to produce a timing signal. There are many...



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