Gate Definition and 248 Threads

Why do TTL integrated circuits assume unconnected inputs to be at logic level HIGH? Does the answer lie in the circuitry itself or some other factor?

I need to automate a gate that is 4.91mtr in length, the motion should be swing type and the angle of rotation to be about less than 180 degree. and the mass of the gate is about 300kg, now should I use a dc motor and if so what should be rating of the same, the rpm required about 5-8...

Why does the SCR remain 'ON' even though the gate pulse is removed? I understood the two transistor model but I want to know the bare physics of it. If you remove the gate pulse only the +ve anode w.r.t. cathode remains, thereby making junction J2 reverse biased hence current should fall of...

Homework Statement A tainter gate for a lake is 21' tall and 14' wide and the water level is 17 feet from the surface to spillway. When the work is done how much water will flow through the gate if the gate is raised 2 ft, 7ft, and 10ft and how high does the gate have to be raised to maintain...

Homework Statement A tainter gate for a lake is 21' tall and 14' wide and the water level is 17 feet from the surface to spillway. What force is the water placing on the gate at the top, middle and bottom? Also when the work is done how much water will flow through the gate if the gate is...

Homework Statement A false mud gate made of common steel for a damn is 6'6" wide, 21'1" tall, and 1/2" thick. Assume a constant density throughout. What is the required force to lift this gate if it were laying flat on the ground and a hoist was attached to the center of gravity? also where is...

Homework Statement It given the expression . how to construct the complex CMOS gate by looking at the expression. Homework Equations The Attempt at a Solution This solution is given as well. I don't understand how he construct it. I know NAND is fromed by two PMOS in...

Hello. One of my friends told me that the logic function for (A.or.B).and.(C.or.D) is From a book, I know the P1, P2 , N1, N2 form a NAND. The same for P3, P4, N3, N4. And P5, P6, N5, N6 form a NOR. My question is, is this circuit the same as (A.or.B).and.(C.or.D) ? Thank you

How to calculate gate resistance, Rg in the JFET amplifier circuit? And What is the function of Rg?

Hello, I am having a bit of an issues rearranging an equation for my solid state electronics class. I seem to have a mental block with this sort of stuff, so I am hoping someone can help. The equation is 0.34 = 1.05((0.64 + |VBS|)1/2 - (0.64)1/2) I know the usual stuff, like + to a -...

Logic gates can be switched to a high state, where the current flow is cutoff and a low state, allowing current to flow through. What electromagnetic processes in the semiconductor material enable this to happen? Since the switching action is purely electronic and there are no moving parts...

Hi Everyone, I am working on an engineering design project for University, and am struggling to calculate the forces some of the mechanical equipment will require. *This is a conceptual design. If anyone would like more details on how it is meant function, or has suggestions, feel free to...

Homework Statement How do I implement ABC'D' using only one 2-input nand gate and one 3-input nor gate? Homework Equations The Attempt at a Solution

http://www.tutorvista.com/content/physics/physics-iv/semiconductor-devices/logic-gates.php I don't know how to post a pic so please go to this site and look at the OR gate why is resistance R connected to the point C. I don't understand its use? I think the OR gate would function without it...

Homework Statement I was looking through some examples in my Digital Logic book and I stumbled across one that gave an answer of x1\uparrow(x2\uparrowx2). The answer I got was x2\uparrow(x1\uparrowx2). After making a truth table I'm finding that these are not equal solutions. Unless, I'm...

Hi there I am working through a quantum gate section of my course and I am a bit puzzled on how to calculate a matrix for consecutive quantum gates. I understand how to generate a matrix for |q0⟩--------[H]------- |q1⟩------------------ Which is simply the tensor product of the hadamard...

Homework Statement Basically and most importantly... I wanted to see if I got my F function correct. That's at clause 2. At clause 3 I'm told a = b = 1 c = d = 0 and to calculate At clause 4 I'm asked if the logic value of P is 1, if the logic value of Q matters... The...

Hello all, Did a lab pertaining to numerous gates (AND, Or, etc) and we decided to measure the input when nothing was connected. We found the voltage to be ~1.06V. Is this voltage we are reading have something to do with the threshold voltage? If not, can someone explain what is happening here...

http://img816.imageshack.us/img816/1640/givenlg.jpg I think I might have exaggerated...

How do you implement different gates by using a two-input multiplexer? What are the inputs supposed to be? How do you implement an AND gate, for example? An OR?

Such as... http://img442.imageshack.us/img442/1999/image201202080002.jpg

Homework Statement how can I implement 4 input xor gate like a+b+c+d (+ means xor gate symbol) Homework Equations The Attempt at a Solution

i don't understand how an applied Voltage on a (intrinsic) Carbon Nanotube could change its conductance... There is not a population inversion like in mosfet. So, which is the physics? Where this carriers can from? thank you.

Homework Statement Sketch the output waveform for the given circuit and inputs (see attachment) Homework Equations For AND gate: x = AB (multiply the inputs to get the output) The Attempt at a Solution attached is my sketch. How to multiply 2 waveforms?

1. Guys how can I draw this equation C.(A(+)B)+ A.B only using Nand gates? 3.I have minimized it but just don't know how to draw it only using Nand gates. Thanks.

How does a NOT gate works in a genuine circuit? Like in a calculator? Thanks in advance, Nexor.

I'm having trouble understanding why the Fredkin gate is universal. I am getting nowhere when I am trying to build a NOR gate, which would prove that the Fredkin is universal. (There's 3 inputs, C, I1, and I2)

Hello all, trying to figure this out. I work at a shipyard and operate/maintain the drydock. The discharge tunnel that flows water out into the ocean has culverts about 24.5' x 15.5' x 8'. Connected to the bottom of the culvert is a 48" pipe that goes to a gate valve of the same diameter. If I...

Is it possible to building one from using AND and OR gates, cause I've been trying and now I'm wondering if it's even possible

Hi, I want to know more about Dual Gate MOSFETs, i.e, their structure, working, advantages etc... Googling "Dual Gate MOSFET" didn't help at all! So please suggest some sources (online) where I can find more information on them. Also, where can I find more information on current...

If an AND gate is basically two switches in series, and an OR gate is two switches in parallel, how would you physicaly make a NAND/NOT/NOR gate? What is physically going on in the microchip which has these gates?

Hi there I'm currently doing a digital fundamentals paper and I was wondering if anyone could identify a logic symbol on the spec sheet attached, and what's it used for. It's on page 4, and the logic symbol is a diamond that is surrounded by 4 traingles. Theres eight of them and it's near...

How do you redraw a three-input OR gate circuit using only 2-input NAND gates?

Transistor "not gate" function I've been trying to understand the following circuit: I'm new to circuitry and electrical engineering, so I've had some trouble understanding the function of transistor Q3 and diode D2, I believe the circuit should function without them. If anybody could...

Aight, so I've been going into/out of the library a lot lately to study since my desk at my flat sucks. I usually listen to music on headphone when walking to/studying in the library, and I have noticed that when I walk through the little security gate things (the two panels on either side of...

Homework Statement True or false: a two input nor gate is designed to have the same worst case rise and fall times. The best case fall time is smaller than the best case rise time in this gate. Homework Equations - The Attempt at a Solution The second part i get, the best case fall...

Hi guys, this is to make something for a uni project I'm doing, not asking for the answers to a homework-type problem so I wasn't sure if it should go in the homework section, but if you think it should let me know and I will move it. So the project background is a timing system for solar...

Hi, I am new to EE. On this page - http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/diodgate.html#c1" - the very first circuit shows a diode-resistor AND gate. How does that work? I understand the OR gate shown right below it, but... the two inputs on this AND gate are connected to reversed...

I am learning about the implementations of digital logic gates using n-type and p-type transistors. With the advent of these two transistors, isn't it possible to have more than one implementation of the NAND gate?

The AND gate 1. When A = 0 and B = 0 both diode D1 and D2 get forward biased and hence conduct. The diodes being ideal, no voltage drop takes place across either diode. Therefore potential difference of 5V takes place across R, with C at zero potential with respect to earth. Thus the...

Hi all, Trying to design a simple gate for the side of our house and in order to select the size of the square tube for the frame, I need to calculate the forces in the members of the frame. I have tried the method of sections and joints, however both do not seem to work. My next...

What is the difference between "Bias" voltage and "Gate" voltage? Well, as the title may indicate, I am wondering what the difference between a "bias" voltage and a "gate" voltage is. I'm looking at some nanoscale systems, and sometimes researchers say they apply a "bias" voltage to a certain...

Hi I am an artist blacksmith student and am looking at building a gate that incorporates engineering mechanisms and am a bit stumped, so I am looking for advise I intend to build a gate from forged steel and cogs I want the gate to be linked to a counterweight that is lifted as the gate is...

Security Gate + Cell Phone = ? OK guys, I have a "how does this work" question. I just moved into a new apartment which has a security gate. Now, aside from a few traditional means of opening, it has a rather unusual method, which I cannot figure out how works. My phone number was entered...

Hello All, I am building a project where I am looking to have a pnuematic cylinder mounted underneath a ramp and push up a gate that is hinged, to 90 degrees, however I am struggling on how to get this to properly function. From center to center of the 2 clevis mounting holes, on the...

Xor gate with negated input and negated output. The expected output is an XNOR gate. I can't get it with boolean algebra. My initial formula is: ((AB')' + (A'B)')' The expected output is: AB + (AB)' right? Please help me.

Homework Statement What happens when you place a NOT gate before and after a NAND gate Homework Equations Current Research(My own work): NOT Gate: A NOT gate is also known as an inverter. It is a logic gate which implements a methodology best known in maths as Logical Negation. In other...

Basically, I'm trying to generate a short pulse when the user pushes a button using a CMOS gate and a rudimentary RC charging circuit. It all simulates fine in Multisim, but I'm concerned what will happen when I run this for real (still waiting for parts in the mail). Here's the diagram...

The discharge of irrigation gate is q=Cd.W.L.sqrt[2g{h1-h2}] where q is the discharge of gate which is veriable value(dq/dt),Cd discharge constant,W is width of gate(constant value),L is opening gate control which is variable value(dL/dt),g is gravity constant,h1&h2 is up and downstream of...

I essentially need the opposite of a NOT gate. I know that sounds silly, but what I'm really looking for is something that will provide the current based on the signal sent to it so that the more sensitive circuitry sending the signal doesn't have to run higher current levels. I've found I...