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.

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  1. S

    Ask a Blacksmith Student: Building a Gate with Cogs & Counterweight

    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...
  2. M

    Security Gate + Cell Phone = ?

    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...
  3. G

    How to make a air cylinder push up a gate

    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...
  4. O

    XOR gate to XNOR gate boolean algebra

    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.
  5. D

    What happens when you place a NOT gate before and after a NAND gate

    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...
  6. S

    Will CMOS Logic Gates Cause Instability in My Circuit Design?

    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...
  7. A

    Discharge gate equation in lablace

    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...
  8. G

    What's the opposite of a NOT gate?

    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...
  9. P

    If gate (NMOS) is connected to Ground how is current able to flow

    I am confused about this example circuit (attached) where the Gate it connected to Ground. I thought in order for current to flow in a MOSFET (i.e. NMOS) a positive gate voltage (Vg) AND Vds (drain to source voltage) needs to be applied. If Vg = 0, how is a channel created in order to allow...
  10. K

    Solving Quantum Control Theory Problem with Toffoli Gate Evolution

    For the sake of simplicity, I'm dropping unnecessary constants like \hbar . I'm working on a problem in quantum control theory, and trying to find a test case to synthesize the ternary Toffoli gate. Unfortunately, I cannot seem to find a basis that admits a possible solution. In order to...
  11. J

    Logic gate circuits - What does two-level and multi-level mean?

    What do "two-level" and "multi-level" gate circuits mean? I have been doing questions relating to logic gates circuits, and have noticed that some questions say "implement with two-level NAND gate circuts" And then a different question would say "implement with multi-level NOR gate...
  12. D

    Floating gate potential of a MOSFET

    Hi, First of all, I posted a similar question in [1] but I think it is the wrong forum and wrong question (maybe the reason why I get no answer...). I have to solve this (I think easy?) exercise: http://img705.imageshack.us/img705/8241/floatingmosfet.png I think (3.1) is easy and I solved...
  13. F

    Proximity Sensors in Metal Detector gate

    I want to use an "inductive proximity sensor" for metal detector gate, but the problem is its range is (generally) under 50mm (2 inches), is there any way I can increase its range? or is there any alternate sensor or way to detect the metal ? Thank you. Faraz Nizamani
  14. H

    Up from Earth's Centre through the Seventh Gate

    Up from Earth's Centre through the Seventh Gate, I rose, and on the Throne of Saturn sate, And many Knots unravel'd by the Road, But not the Master-Knot of Human Fate. The blasphemy of somebody like me is not easy and exorbitant, There isn't any stronger faith than my faith, If...
  15. S

    Why does a MOSFET heat up with slow rise/fall times at gate?

    I have a pulse width modulator that's composed of a triangular wave generator and a comparator. This outputs a pulse width modulated signal, whose duty cycle I set by changing the comparator's V- voltage. I have measured the rise and fall times of my output waveform and they are 27uS (for...
  16. A

    Calculating the Frequency of Oscillation for an Oscillating Gate with Spring

    I need to find the frequency with which the gate will swing in Rad/s. I know the mass is 2kg, the moment of inertia about the hinges is 0.36kgm2 and that the torsional spring stiffness is 18.2Nm/rad. A person pushes the gate open to 90degrees and then it's released. Damping is negligible. If you...
  17. L

    Electronics and logic gate question

    I know this is probably in the wrong board, but. I'v just been looking into some Boolean algebra to convert truth tables into a set of logic gates representing a circuit. If i were attempting to represent a certain truth table, but i was limited to ONLY using NAND gates. (their the only...
  18. A

    What Sections of Goldstein's Textbook Should I Study for GATE Physics?

    Hi Guys, I have completed my BE in E&C however now i am preparing for GATE Physics 2010. I have completed the basic Classical Mechanics along with all the exercise problems from the textbook "University Physics" by Young and Freedman. As you all know the actual GATE syllabus starts from the...
  19. S

    Making OR/NOR Gates: Is it Possible? How?

    Is it possible to make an OR / NOR gate from AND / NAND / NOT gates? If so, how? Sorry for the simple question but I'm a little confused...
  20. K

    Implementing an early-late gate synchronizer

    Hi there. I am working on a study-oriented university project on digital modulation techniques. I am trying to implement a scheme of early-late gate synchronizer to latch on to the pulse instant. Can you help me with the different ways of doing it? along with any suitable analysis and...
  21. J

    How Do I Build a Logic Gate for a Voting System?

    Homework Statement I'm studying logic gates and trying to create my first one. Homework Equations 3. In a TV programme, the panel votes on new performers. The panel consists of a Chairman (C) and three others (X, Y and Z) who each press a button to register their vote. The SUCCESS light is...
  22. S

    Force exerted by water on gate

    Homework Statement http://www.pictureshoster.com/thumbnails/fzfnh5lyl6epxx11dmp_thumb.jpg the gate is connected by a hinge at point A and a force holds it shut at point C water density \rho=1000 kg/m^{3} width of the gate is 1m (into page) Homework Equations F =...
  23. X

    Solve Farm Gate Problem: Horiz Force on Bottom Hinge

    Old MacDonald had a farm, e i , e i , oh ! And on that farm he had a gate, e i , e i , oh ! And a squeak, squeak, here. A squeak, squeak, there. And a squeak, squeak, everywhere . . . The gate is ℓ = 3 m wide and h = 2.47 m tall with hinges attached to the top and bot- tom. The guide wire...
  24. A

    Confirm Gate, Drain, Source in Image

    Just want to confirm i have this correctly.. in the following image: from left to right, its Gate, Drain, Source ? it doesn't say on the datasheet http://www.irf.com/product-info/datasheets/data/irf640n.pdf
  25. E

    Is My Motor Sufficient for a 1500kg Sliding Gate?

    hi everyone, i have slidig gate that i need to install a drive motor. the gate weight is 1500 kg and has 5 v-grove wheels. the dia. of the wheels are 160 mm. We already bought a motor for it but i am concerned about if that motor will be sufficient for this gate. i am trying to calculate the...
  26. Phrak

    Does a c-not gate conserve angular momentum?

    Does a c-not gate conserve angular momentum?
  27. C

    Any gate i can substitute to xor gate?

    any gate i can substitute to xor gate? if i don't have xor gate what gate i can use to substitute it?
  28. N

    Quantum logic gate measurement?

    Do quantum logic gates perform measurements? (collapse the wavefunction) For example: If I apply a cNOT gate to a pair of cubits with wavefunction 1/\sqrt{2} |10> + 1/\sqrt{2} |00> what would I expect as the result? 1/\sqrt{2} |11> + 1/\sqrt{2} |00> ? or 1|11> or 1|00> or...
  29. S

    How can I simplify this circuit using boolean algebra for XOR and XNOR gates?

    I want to simplfy M'(A'B'C+ABC')+M(AB'C'+A'BC) to as simple a circuit as possible. I don't know the boolean algebra to simplfy the ABC terms. Help please, Speck
  30. A

    Current limiting resistor for led on 7408 gate output

    I am building a 2 to 4 decoder with 7408 And gates and need to put LED's on the output as indicators, active high. 2 questions 1. Would I put a current limiting resistor in series with the LED to ground or put the resistor and LED from the gate output to Vcc? 2. The LED draws 30mA at 2V...
  31. C

    Thought experiment - micro gate

    This baffles me, because the device outlined below could create energy ... Theres two tanks A & B with a microscopic gate between them Air in A & B starts at say 25 degrees whenever a faster than average moving molecule approaches the gate in A a sensor opens the gate and let's in pass...
  32. D

    Controlled NOT Gate: Explained

    I'm not sure where to post this, so here it is: \left[\begin{array}{cccc} 1&0&0&0\\ 0&1&0&0\\ 0&0&0&1\\ 0&0&1&0\\ \end{array}\right] How is this a controlled NOT gate? If I multiply this with \left[\begin{array}{c}1\\0\\1\\0\end{array}\right], the second bit is flipped regardless.
  33. K

    How to Calculate Tension in a Hinged Gate with an Off-Center Load

    Homework Statement A gate 4.00 m wide and 2.00 m high weighs 528 N. Its center of gravity is at its center, and it is hinged at A and B. To relieve the strain on the top hinge, a wire CD is connected to the gate at an angle of 30 degrees. The tension in CD is increased until the horizontal...
  34. K

    Troubleshooting a Three Input AND Gate Circuit

    Okay, so I am trying to use the breadboard and I have a hard time with a three input AND gate. Guess I can do a schematic http://imageiso.com/out.php/i17298_3inputandgate.JPG So in my bread board, I have pins 1 and 2 as inputs..with pin 3 as a LED (output), and I have a jumper connecting...
  35. N

    NOT Gate Feedback: Explaining Output Voltage Changes

    If I have a simple TTL NOT gate and had a feedback line from the output to the input, then how would I explain what happens to the output voltage for certain inputs? Does it just simply oscillate continuously?
  36. P

    Creating an OR Gate with Two TTL Output Signals

    Hi there, I have a simple question. OR gate between 2 output TTL signals can be done with diodes and simply join the signals toguether... ? Output TTL signals have a pull up resistor included: For one output: --------------- Output level 1) 5 V / -4 ma Output level 0) 0.7 V / -16ma...
  37. A

    NAND or NOR Logic Gate, which is less reliable at higher speeds

    Trying to find out information on NAND and NOR logic gates and which, if any, may be less reliable at higher speeds. Supposedly this would have something to do with propagation delays and triggering times.
  38. P

    Understanding the Region of Operation for CMOS Transmission Gate: VDD vs Ground

    Hello, I'm supposed to determine the region of operation of both the n-channel and the p-channel MOSFET'S when the control voltage is at VDD(5V) and both I/O terminals are at VDD. Also I have to figure out the region of operation when the control voltage is at VDD but the I/O terminals are at...
  39. D

    OR Gate Voltage Drop: A=5V, B=4.6V

    Hi! I've got another diode OR gate problem. When the voltage at the input A is 5V and it's 4.6V at the input B, does the output voltage still remain at 4.4V? Does it mean that the D2 diode is forward biased and its voltage drop* is smaller than the voltage drop of the D1 diode? *the...
  40. D

    Diode OR Gate - the role of resistor

    Hi! What would happen if the resistor in the attached diode OR gate removed (connection with the ground would be preserved)?
  41. D

    Choosing Resistors for Diode AND and OR Gates

    Hi! There's a schema of a diode AND gate attached. Could anyone of you, please, explain me why the voltage drop across the D1 diode is so big compared to the voltage drop across the D2 diode? Thanks a lot in advance!
  42. D

    What is the Circuit for a Diode OR Gate with a 12V Battery Backup?

    Hi! http://www.phys.uAlberta.ca/~gingrich/phys395/notes/node71.html" 's an electrical network for a diode OR gate. It says there that "[t]he 12 V battery does nothing until the power fails; then it takes over without interruption." I just wonder what electrical circuits (closed loops) are...
  43. Hans de Vries

    High-k/Metal gate transistors going into production at Intel, IBM and AMD

    After many years of research, micro processors will be build of transistors using different materials as have been the case in the past 40 years: "Gordon Moore, 78, came out of retirement, where he spends some of his time in Hawaii, to issue a statement Friday about the Intel team's...
  44. M

    Confused on Gate Delays, what would the wave form look like?

    Hello everyone, I'm lost on how to interpret wave forms in VHDL given a certian logical gate. For example: If I have 2 nand gates, that look like this: https://cms.psu.edu/AngelUploads/Content/MRG-060818-113032-mji/_assoc/EB238A71723B494FBF1CC149443E7B49/nand-nand.bmp?1703 And the...
  45. A

    Calculating Force & Pressure for a Reservoir Gate

    hi guys. got another question for ya. ....... seems to of uploaded small but i explain. a reservoir is designed to retain water to a max depth of 10metres. if the water level exceeds 10 metres, then a hinged semi circle gate will open to release any excess water. the gate has a...
  46. electronic engineer

    How can the NE555 be used to create a NOT GATE?

    is there anyway to Design NOT GATE using NE555?
  47. X

    Engineering Need help understanding the transistor circuit of an Boolean NOT gate

    need help understanding the transistor circuit of a Boolean "NOT gate" can some one please link or upload a scheme or would this one i attached work? and how do you display in which direction the current flows? that's what I'm trying to show with the battery halves...
  48. J

    Can't seen to get the right solution-A sluice gate dams water up

    Can't seen to get the right solution- A sluice gate dams water up 5m. A 1-cm dia hole inthe bottom of the gate allows liquid water at 20C to come out. Neglest any changen in internal energy. Find exit velocity and mass flow rate. governing eqn- hi=he+1/2v^2 I found...
  49. marlon

    Can Organic MOSFETs Detect Neurotransmitters?

    Hey guys and girls, Just letting you know some of the work that a few people here at IMEC have been working on. This really is a serious enhancement towards the development of organic transistors. Basically, what happens is the replacement of the metal/poly-silicon gate in a MOSFET by an...
  50. M

    Finding a min gate input count realization of enabling logic ?

    Hello everyone, I'm confused on what they want me to do here: it says: Find a minimum gate input count realization of the enabling logic using AND and OR gates and inverters. Well This is my truth table i came up with, and the "enabler" is the M, the master switch( 0 secruit system on, 1...
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