What is Gate: Definition and 259 Discussions

A gate or gateway is a point of entry to or from a space enclosed by walls. The word derived from old Norse "gat" meaning road or path; But other terms includ yett and port. The concept originally referred to the gap or hole in the wall or fence, rather than a barrier which closed it. Gates may prevent or control the entry or exit of individuals, or they may be merely decorative. The moving part or parts of a gateway may be considered "doors", as they are fixed at one side whilst opening and closing like one.A gate may have a latch that can be raised and lowered to both open a gate or prevent it from swinging. Locks are also used on gates to increase the security. Larger gates can be used for a whole building, such as a castle or fortified town. Actual doors can also be considered gates when they are used to block entry as prevalent within a gatehouse. Today, many gate doors are opened by an automated gate operator.

View More On Wikipedia.org
Recent contents Top users
  1. G

    Fluid Mechanics- Pressure on a gate

    Homework Statement http://imgur.com/vXkg0 Homework Equations Fw=γAH Ycp=bh3/(12)(h/2)b + (h/2) The Attempt at a Solution I found the angle of the gate from the horizontal to be 53.1 degrees. Using this, I found y to be 2.5m and H (vertical distance to centroid) to be 6 m...
  2. N

    NOT Gate: Inverting Inputs & Current Flow - Help Clear Confusion!

    From what I learned at school today.. Afaik NOT gate acts as an inverter, right? Which means if input is 0, output will be 1 and vice versa. My question is, if input is 0 then output will be 1. From where does the gate gets its current flow? Since input is 0. Or, it cannot be used like...
  3. T

    TTL Gate Circuits: Unconnected Inputs Logic Level HIGH?

    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?
  4. A

    Automating a 4.91mtr Swing Gate with 300kg Mass

    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...
  5. P

    Why does the SCR remain 'ON' even though the gate pulse is removed?

    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...
  6. B

    Rate of flow through a damn gate

    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...
  7. B

    Force from the water on the gate

    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...
  8. A

    Applying a gate to entangle states

    Homework Statement Part of a past paper, I can do all of the question a-d without problems but the second part of e) is giving me trouble. So you have the following state \frac{1}{\sqrt{2}}(\mid 0 \rangle_{A} + \mid 1 \rangle_{A})\mid 0 \rangle_{B}\mid 0 \rangle_{C} You apply a...
  9. B

    Calculating Force & CG of False Mud Gate Made of Steel

    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...
  10. N

    Constructing Complex CMOS Gates | Understanding NAND and NOR Logic

    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...
  11. N

    CMOS gate for the logic function

    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
  12. C

    How Does Gate Resistance Rg Impact JFET Amplifier Performance?

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

    Rearranging equation to find back gate bias

    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 -...
  14. B

    How does a logic gate permanently maintain its state?

    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...
  15. T

    Force Requireed to Close the Gate on the Bottom of a Hopper

    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...
  16. N

    Implement ABC'D' using only one 2-input nand gate and one 3-input nor gate

    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
  17. J

    Understanding the Role of Resistance in an OR Gate Using Diodes

    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...
  18. D

    Pretty simple NAND gate question

    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...
  19. F

    Quantum Computing gate matricies

    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...
  20. Femme_physics

    Logic Gates with XOR gate need to verify solution

    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...
  21. S

    MOSFETs and floating gate potential

    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...
  22. Femme_physics

    Building a logical gate function with NAND gates only

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

    Digital circuits 2-input multiplexer implemented into an and gate

    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?
  24. Femme_physics

    In logical gates - can I combine signals without a gate?

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

    Implementing 4-Input XOR Gate: a+b+c+d

    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
  26. Z

    Admissions Preparation for GATE exam for admission to IISc/IITs

    Hi, I'm an engineering student pursuing BE(bachelor in engineering) in electronics and communication. Right now I'm in my 2nd year(of the 4 year course). I plan to appear for the GATE exam in my final year, for admission to MS/MTech programmes in IISc/IITs(Indian Institute of Science/Indian...
  27. W

    Carbon Nanotube FET: Gate Voltage and Conductance

    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.
  28. S

    Sketch output for 2-input AND gate

    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?
  29. T

    Draw C.(A(+)B)+ A.B Equation using Nand Gates

    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.
  30. N

    Real-Life NOT Gate: How Does It Work?

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

    Can't understand the Fredkin gate well

    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)
  32. E

    Designing CMOS Logic XOR Gate & 2:1 Multiplexer

    I am designing cmos logic xor gate and 2:1 multiplexer. In my design i am using 8 pmos and 8 nmos for 2:1 mux and 6 pmos and 6 nmos for xor gate. I am using pmos and nmos to implement complement A, means that i am not using complement directly into the circuit. So , i want to know that is it...
  33. S

    Determining flowrate (GPM) through a partially open gate valve

    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...
  34. A

    Build NOT Gate w/ AND/OR Gates: Possible?

    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
  35. T

    Real world problem - Swing gate actuator forces

    This is a very long argument between me and a supplier of a electric linear actuator for opening gates. In the image below you can see how I currently have the gates configured, and how they are suggesting I have them configured. My question is this... Would I be correct in saying...
  36. P

    Zz.What is the theory behind Dual Gate MOSFETs and current controlled diodes?

    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...
  37. F

    Can a NAND gate be made without using a negative supply?

    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?
  38. A

    Identifying Gate Logic Symbol on Spec Sheet: Digital Fundamentals Paper

    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...
  39. D

    Engineering Redraw Equivalent Circuit for 3-input OR gate

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

    Transistor not gate function

    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...
  41. X

    Fluid dynamics (continuity equation), pressure on gate

    Homework Statement Consider the cross section of a sluice gate, which is a device for controlling the flow of water in channels. Determine the force on the gate per unit width of the gate. Hint: think of each line as a surface, with the length given above, and 1 foot of depth in the direction...
  42. Disconnected

    Anti theft gate things in shops/libraries.

    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...
  43. T

    2NOR gate rise and fall time question

    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...
  44. X

    Adjustable sensitivity IR Light gate

    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...
  45. E

    Two Diode AND Gate - New to EE

    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...
  46. C

    Is the implementation of the NAND gate unique?

    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?
  47. A

    AND Gate: A, B and Y Explained

    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...
  48. V

    Calculating Forces in Gate Frame Members: Am I on the Right Track?

    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...
  49. H

    What is the difference between Bias voltage and Gate voltage?

    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...
  50. N

    How do wrap-around gate CNTFETs work?

    Hello, I do my physics coursework about Graphene and carbon nanotubes. In this context i mainly have to talk about them replacing silicon in transistors like (MOS)FETs - Wrap-around gate CNTFETs Homework Statement I know how a standard silicium-MOSFET works, the is the source, and the...
Back
Top