In this project you will build a coin toss circuit. It has three sections: a square-wave oscillator, a JK flip flop, and two LEDs (red & green). It uses CMOS digital ICs and MOSFET transistors. The schematic does not show the power and ground connections for the ICs. When powered from a 9V battery, both LEDs will light. When you press the switch, one LED shuts off and the other stays lit; but which one There`s
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a 50-50 chance for either color. The square-wave oscillator uses one gate in the CD4093 IC. The IC contains four 2-input NAND gates as shown in figure 2. Digital signals are either high (+V) or low (0V). The output of a gate will switch between high and low depending on its inputs. The input-output behavior of a gate is defined by its truth-table. Table 1 is the truth-table for a 2-input NAND gate where A and B are the inputs and X is the output. A 0 represents low (0V) while a 1 represents high (+V). Mistakes happen, and unsoldering an IC is tedious. So in this project we will use IC sockets. Refer to figure 6 to see how the parts are arranged on the board, including jumper wires. Figure 7 shows how the parts and jumpers are soldered. Note that the leads of the switch need to be adjusted slightly to fit the holes in the board. Figure 7 shows the two strips of copper that run along the top and bottom of the board. They are used for +9V (red wire on battery clip) and ground (black wire). Drill a 1/8 inch hole between the two existing holes. Then feed the battery clip wires through and make a small knot. Then feed the black and red wires through the other two holes as shown. In figure 6 you can see the red and black wires inserted into holes and soldered on the copper side. Note the bare-wire jumpers, including the one between the two ICs which brings +9V to pins 5 & 6 of the CD4027. Since I cut the board down, it turned out...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
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In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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