International Shipping We ship internationally, no matter where you are. Circuit Description As previously mentioned, the IC 74LS is an 8-bit synchronous shift register able to produce 8 serially incrementing logic high outputs in response to an applied clock signal. If you are wondering how to make an LED moving sign DIYthen probably you would like to refer to a few of the circuit designs already published here on Bright Hub. Buy anytime and get the free shipping offer. However the above circuits are either too basic and ordinary 74l too complex and difficult with their designs. Agilent Count Digital Multimeter.
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Unlike ordinary CMOS ICs which has also been discussed in many of my previous articles , the above ICs are equipped with many different built-in features which may be accessed or activated by just applying the appropriate logic inputs or components to their relevant pin-outs. Similarly the IC requires only an external clock signal to make its outputs swing into action and produce interesting logic sequences.
Circuit Description Referring to the figure on the left we see that externally it looks just like an ordinary pin dual in-line chip. The extreme top left pin from the printed side is the first pin in the order, and the pin just opposite to it on the other row is the last or the 14th pin.
The following data gives its pin-out specifications: Pin 14 is supply positive input, Pin 7 is the negative or the ground pin of the IC, Pin 8 is the clock input and receives externally applied oscillations, Pin 9 is the reset input, Pin-out 1 and 2 are the serial inputs of the IC. The remaining pin-outs are all the outputs of the IC.
The serial inputs pin 1 and 2 of the IC has a special purpose of resetting the above procedure in an interesting pattern. For example if the pin — outs 1 and 2 are permanently connected to the positive supply and the reset pin is joined to the last output of the IC pin 13 , then, as discussed earlier, once all the outputs become high the last pin 13 instantly resets the whole circuit, shutting the whole array of outputs, and the cycle repeats.
Now suppose if through a simple wiring pins 1 and 2 are configured in such a way that when the last pin 13 of the IC goes high while sequencing serially, it grounds the serial input 1 and 2.
The whole output array, instead of shutting down all together, now starts receding sequentially one-next-to-the-other, until all of them are shut down to begin the cycle all over again. This opposite sequencing also takes place in accordance to the rising pulse of the input clocks. Hopefully you will get to see another article pretty soon, which will explain the practical utility of this wonderful IC. Post navigation.
How Would You Build Moving LED Signs Using IC 74LS164? Pin-Outs Explored
74LS164 Integrated Circuit (IC)