Shaktilabar Nov 24, Nov 23, 8, datashet, If you are using TTL which your part number implies, but which I suspect may be somewhat inaccurate you will need to take into account the input currents. What is the debounce device you purchased? What is the IC, and how does it work? I cannot get this circuit to work correctly on my breadboard at home and dont know why! Jun 18, RCO of the second counter will go high when the output is 99, so this can be used to enable a third counter, which will then count hundreds.

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Juhn It is explained in the application notes yd-tech. Post as a guest Name. What is the problem that you see? If this is true, on a count of 9 the RCO output will go high. Hello, Have a look at page 11 of the attached datasheet.

My problem is, every switch i use, i have to press a lot to even get a reading, then when i get a reading its not always accurate. Building a simple clock. Thanks Steve, that needed saying. They will have timing diagrams which explain all this.

Consider this aspect when you look at the alternative methods of debouncing. How do I make a propeller clock? How does ICS work? I am using my 74ls47 7 seg driver in conjunction with one of the two 7 seg displays on my dual 7 seg. If you do a preset to 6, the counter will go 6,7,8, Sep 16, 5. This number represents capacitance in farads: Highlights from the Hot Chips Symposium A hub for technological innovation and inspiration, Hot Chips delivered tutorials, presentations, and more.

Can someone tell me what is use of that pins in counter? Start Now at quora. Dustin, I recently last week built that exact debounce cct for the input of a 3 digit counter. What is IC and IC? How does a Counter IC works? Dtasheet first it just stayed at 0 and didnt change, then i unconnected the Common cathode mine only has one on datasheft 7 seg and re connected and it counted all the way to 8 but then stopped.

Any advice to get this working would be extremely helpful! Most chip makers really want you to know what there chips will do and give you some guidelines for using those parts because they hope to be included in the design of some hugely popular product, so they can sell a ton of those parts. Need to create a 5V clock signal. Then you need a BCD counter remember it goes from 0 to 9 only.

But regardless what else you do, get a copy of the datasheet and study it, because included in that document will be the voltage and current limits of that chip and the pin out, information without which, you stand a good chance of destroying that chip. Remember that after 5 time constants a RC circuit has settled down completely. Home Questions Tags Users Unanswered. May 19, 8. You May Also Like: For the theory on switch debouncing, try http: How about having the circuit settle in 20ms?

Look at the truth table for details. I am now getting a clean count with my debounce IC. Ask a Question Want to reply to this thread or ask your own question? TTL will weakly pull high so that a disconnected input seems to be at logic 1 although its noise immunity is minimal.

At a count of 78 the output of the NAND will go low, and on the next clock the counter chain will reset to 0, and the cycle will repeat indefinitely.



For faster clock rates, the carry lookahead connections shown in Figure 2 are recommended. Counter and ROM A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. The TC output datashfet subject to decoding spikes due to internal race conditions and is therefore not recommended for use as a clock or asynchronous reset for flip-flops, registers or counters. The circuits have four fundamental modes of operation, in order of precedence: The clock inputs of all flip-flops are driven in parallel through a clock buffer. Maximum test duration 2. Documents Flashcards Grammar checker.



Kazisar Maximum test duration 2. The TC output is subject to decoding spikes due to internal race conditions and is therefore not recommended for use as a clock or asynchronous reset for flip-flops, registers or counters. The circuits have four fundamental modes of operation, in order of precedence: Documents Flashcards Grammar checker. They are synchronously presettable for application in programmable dividers and have two types of Count Enable inputs plus a Terminal Count output for versatility in forming synchronous multistage counters. Fairchild does not recommend operation of circuits datasheft databook specifications. In this scheme the ripple delay through the intermediate stages commences with the same clock that causes the first stage to tick over from max to min in the Up mode, or min to max in the Down mode, to start its final cycle.

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