Minute Alarm Clock Thania Miah, Yogeeta Toramall, Reana Ramkhallawan, & Magi Mohamed Forest Hills High School, and High School for Health Professions and Human Services Thani_13@yahoo.com, yogeeta875@yahoo.com, Magi.mohammed08@gmail.com, & reana515@yahoo.com David Peled LaGuardia Community College davidp@lagcc.cuny.edu Abstract Today s society is all about advancements in technology. A study was conducted to help people understand how technology was designed to make tasks perform. Technology is nothing more than thousands of logic gates combined to make a certain task work. Logic gates perform a logical task, where one or more inputs release a single output. Using this concept, the objective of this project was to create a military clock. To create a military clock we used the knowledge of basic logic gates such as the AND, NOT, OR, and NAND to get this task accomplished. Using these gates on a circuit board along with Flip Flop and clock helped us to create the minutes up to 59 and resetting itself automatically to 0. Using Flip Flop and clock together helped us stop the count at 59 and to not continue up to 99 then going back to 0. This is because when these devices are connected, the clock will receive an impulse to stop at 59 and reset back to 0. During this project we found out that technology works in a simple true or false function also known as a Boolean Expression according to C. Wood. That any 0 (false, no, or not true input) and 1 (true, yes, and not false input) will lead to a true or false output. In conclusion, when we want a digital device to do something it will give you a yes or no option and you decide what you want. This is how technology performs tasks. Introduction In this experiment, our goal was to design a 24-hour military clock. Before designing, we had to learn the basic principles of electronic gates. According to C. Wood, "logic gates are the building blocks of digital circuits." The most common gates that we learned were the "-and", "-or", and "-not" gates. Upon studying gates, we learned the concepts of inputs and outputs. In order for a gate to function, there must be an input or multiple inputs, except the NOT gate, which only has one input. The inputs can only be two numbers which are 0 and 1. These inputs then result with outputs that are also in the form of 0's and 1's. These 0's and 1's can represent something being true or false; or high and low; or a switch being turned on and off. However, that depends
on each gate's situation. For example, with the AND gate, the output is only true when both inputs are true (1). If that is not the case, the output is false (0). With the OR gate, the output will be false if both inputs are false. Also, if either or both inputs are true, the output will be true as well. As for the NOT gate, it negates the input being that it only has one input. An example is if the input is 0 (false), the output will be 1 (true). These gates can be combined to form other gates. For example, when the NOT and the AND gates are combined, they form the NAND logic gate. In addition to that, if the NOT and OR gates are combined, the NOR gate is formed. These combinations of logic gates form circuits designed with specific tasks in mind. Experimental Procedure and Setup This experiment must be constructed on a circuit board. The parts of the board must be understood before building the alarm clock. The clock must first be connected to all the T s in the first four flip flops. The resets in every flip flop should be connected to each other. The Q in FF1 (flip flop 1) is connected to the J and K of FF2 and it is also connected to the input of the first AND gate. The Q in FF1 is connected to (1). The Q of FF2 is connected to the input of the first AND gate and also to (2). The output of the first AND gate connects to the input of the second AND gate and connects to the J and K in FF3. The Q of FF3 is connected to the input of the second AND gate and connects to (4). The output of the second AND gate is connected to the J and K of FF4. The Q of FF4 is connected to (8). All these steps are repeated for the next four flip flops. The only difference is that the T in FF5 will not be connected to the clock. In both sets the EN is grounded. The Q in FF2 connects to a NOT gate and the output of the gate is connected to the input of the first OR gate. The Q in FF4 connects to a NOT gate and the output of the gate is connected to the input of the first OR gate. The Q in FF3 and Q in FF1 are connected to the input of the first OR gate. This is repeated for the second set of four flip flops. The output of the second OR gate goes to reset. The output of the first OR gate is connected to first T in the second group of four flip flops. The Q in FF5 is connected to NOT gate and its output is connected to the input of the NAND gate. The Q in FF7 is connected to NOT gate and its output is connected to the input of the NAND gate. Both the Q in FF6 and FF8 are connected to the NAND gate. The output of the NAND gate is connected to reset.
Diagram 1: Circuit board diagram of an alarm clock.
Experimental Results and Discussion This experiment had led to creating a minute based alarm clock on a circuit board. The circuit on the board counts up to 59 and resets itself automatically to 0 exactly like the minute digits on a clock. However when combined with the hours, minutes and seconds it becomes an actual clock. Constructing an alarm clock needs the basic principles of the AND, OR, NOT, and NAND gates including the knowledge of the truth tables. The truth tables were based on L. Wittgenstein s ideas and theories. Table 1: truth table for the AND gate. input input output 0 0 0 Table 3: truth table for the NOT gate Input Output 0 1 1 0 Table 4: truth table for the NAND gate (NOT AND). input input Output 0 0 1 0 1 1 1 0 1 1 1 0 0 1 0 1 0 0 1 1 1 Table 2: truth table for the OR gate. input input Output 0 0 0 0 1 1 1 0 1 1 1 1 Conclusion During our experiment, we had encountered many challenges. One of those challenges was to get the numbers to reset at 59. That took us quite some time to figure it out. However the understandings of basic logic gates assisted in completed the experiment which had worked accurately. Acknowledgments We thank our professor s assistant Mithlesh Dev for assisting and guiding us during the experiment. We gratefully acknowledge LaGuardia Community College college now program for providing us with everything that was necessary.
References Calderwood, D. Introduction to Logic Gates. http://isweb.redwoods.cc.ca.us/instruct/cal derwoodd/diglogic/index.htm Wittgenstein, L. (1992) Logical- Philosophical Trestise. Wilhem Ostward s Annalen der Naturphilosophie http://en.wikipedia.org/wiki/tractatus_logi co-philosophicus