Lock Definition and 69 Threads

TL;DR Summary: Want a lock that unlocks when flipped upside down As the TL;DR summary says, I am trying to come up with a design for a lock that unlocks when it is flipped upside down. I've looked into spring loaded locks and different lever devices but no luck. Hoping someone can assist...

While my hunky husband was lifting the chair up, and my brawny brother pushing the frame down, I kept hitting the top of the slide with a screwdriver, to try to loosen the slide. But these parts are still wedged too tightly! We ran out of energy and ideas! How can we life hack this please...

Hello! I have a laser with only one input for external signals. Currently I use that to send the error feedback signal when I measure the power transmission from my cavity (not using PDH). If I want to use PDH, I would need to modulate the laser frequency, which means that I need to send to the...

I'm designing something and part of it has a aluminum block that will be have a M6 threaded hole. I want to add a nylon washer to give it a stop nut or lock nut type of feature. I'm looking for input into the appropriate diameter and dimensions of the washer. also I'm wondering if there are any...

I got this honda crv 2004 rear cargo lock actuator accidentally replaced when it was working.. although Honda said it might not be working. So I want to check if it is really working or not. Which of the 5 terminal can move the actuator by suppying with 12 volts DC supply? I watched a lot of...

Homework Statement A password has numbers 0-9 in it. The password is 5 digits, repeats are not allowed, and order doesn't matter (I just have to have the correct 5 digit buttons depressed). A. If I guess at the password, what is the probability that the box will open? B. If I have completely...

I am currently working on designing a linear brake/lock for a completely different purpose but it will be based on the same principle as in a quick clamp shown below. Before building a prototype I do want to make some rough calculations to check dimensions, angles etc. etc. However, I am for...

Hi guys, The only use of "scroll lock" I am aware of is in Ms Excel. If you press scroll lock after you have selected a cell, you can go up and down (within the worksheet) by pressing PgUp and PgDn without the cell being deselected. Does anyone know other uses of "scroll lock" button?

SO, here is the case guys. I have a mechanism to turn plate by a motor. Both motor and plate was connected through 2 spur gears. But here is the problem, when wind strike the plate, the plate start to rotate even without the power of the motor. What is the best way so i can prevent the plate...

Can anyone help me in what they think would work as far as placing a locking mechanism on a watch band?? I need it to lock onto the wrist. So it can not be taken off by the wearer. I do not want it to need any type of key or source that can be lost. I have been recommended a bluetooth type of...

Today I just learned the concept of magnetic lock.. where pure electromagnetic force was used to lock doors.. My experience with magnets shows you can still pull two magnets apart.. but for magnetic lock.. there is no moving part, the door is closed just by the turning the electromagnets on and...

Does somebody knows why the output changes with the change of the sensitivity? When I'm measuring noise, let say I have a value of 5nV/sqrt(Hz) at 10 nV sensitivity. When I switch to 20 nV, the output goes to 10nV/sqrt(Hz). Why? Which on is them the correct?

Hello, I'm using a lock in amplifier (model 5210 from signal recovery) for some experiments with photodiodes. Firstly, there is an optical chopper that "feeds" the lock in (reference signal). My input is a photodiode (in current mode). The problem is,the unlock (unlk) light is always on in the...

Can a parent body be tidally locked with a moon, so if one was standing on the planet the moon would appear in the same location in the sky day and night?

Hi All. I am stuck in a problem. Please check the image attached. It's part of a foldable mechanism of a quad copter arm. The red part is fixed to the body, the grey part is fixed to arms. The transparent part is a threaded collar/sleeve. The yellow part is a stopper. The hinge is a connecting...

When 2 bodies are locked over relatively large distances (like locked Earth and Venus), do they lock, naively speaking, to the position where another's body is seen (delay distance/c is taken into account) or to the position where other body is actually at the moment (because of Relativity of...

Consider the following; We have Earth with two moons in orbit (discounting the existence of our own moon for the sake of this hypothetical scenario). One moon is the size and mass of Pluto, orbiting around 70,000km from Earth. The other is the size and mass of Pluto's moon, Charon, orbiting...

Would an Earth-like planet while getting a tidal lock, get it influenced by landscape of surface? So that the most stable state would be to have a continent on the center of the side close to its star and the other on the exactly opposite side? Or maybe because of hydrostatic equilibrium such...

Homework Statement The flat piece is between 2 walls and is pushed eccentrically by force F. what should be the relation between the width x and the height y in order to achieve self locking (that the piece won't go down)? Homework Equations Friction Force: f=μN Balance of moments: F1L1=F2L2...

So my co-workers and I have had a dispute after hearing a podcast on NPR about Earth's rotation. One question was about what would happen if one side of the Earth always faced the sun (tidal locked) and another question was about what would happen if the Earth stopped rotating. From what I've...

Hi, I wrote a simulation of lock in amplifier using Matlab and now i want to test it for different SNR. I added to the signal white gaussian noise. In all the spec that i read, always written that the lock in amplifier can handle -100dB of noise. When I add a noise of SNR=-30dB the lock in...

Would a planet before getting a tidal lock to its star have for some transitory period days which would be centuries long? Or is there a threshold where it would just get from long days suddenly to tidal lock with everything levelling out?

trying to plot the movement of the instantaneous centre of lock jaw pliers first image is an example of the 4 bar link and the second is a sketch which I've drawn of what i think it would be. is this the only instantaneous centre?

Hello- First post here, I can't seem to wrap my head around this concept and how to overcome it. I read here: https://www.physicsforums.com/threads/air-lock-concept.83124/ that air's compressibility is what stops flow, why is this? I also read that a stronger pump (in a vehicle's fuel system...

Hi! I have to understand how a parking lock described in a patent works, but I cannot really get it. The text is french, however, there is an online translation into English. The link to the patent is the following...

Hi, I am in my first year of physics and am a bit lost. I need to know how to show the effectiveness of ABS using numerical examples and the formulas used.

Homework Statement The attached plan view of a pair of lock gates. Each gate is supported on hinges at the edge of the channel. The gates are retaining 2m depth of water on the hatched side. What is the contact force between the gates where they touch in the middle? Density of water =...

So here is my dilemma: We have our SR830 in a MOKE set-up. The modulation of the laser is with a chopper at approximataly 336 Hz. The reference signal is not being picked up by the SR830, but using the same cable the reference frequency is coming up on our oscilloscope. ie, plug the cable...

For context: I'm building a handle that needs to rotate in all directions. The handle will be placed inside the spherical bearing - and the bearing will allow it to rotate as it's required to. The handle will also need to be able to be locked in place at angles chosen by the user. Whatever...

Homework Statement a standard combination lock consists of a password which is 3 distinct numbers between 00 and 59. a) compute the number of valid passwords b) compute the probability that the password is a palindrome. eg. 03 - 22 - 30 is a palindrome (same backward as it is forward) c) the...

Force need to break a magnetic lock NOT SOLVED So rest assured I'm not planning a prison break. I work in a secure treatment center for adolescents and the other night we had an escape. Many of the staff are amazed at the ease they busted the lock. I looked at it and there is a lot of play on...

What's the volume of water required inside the lock if... The dimension of the lock is:40 long x 3.5 height x 6 width allowing 0.5 height. The ship weights 400T plus 300T(LOAD) total= 700T whats the amount of water used per lock allowing allowing 0.5 m from the height? What if the...

What's the volume of water required inside the lock if... Homework Statement The dimension of the lock is:40 long x 3.5 height x 6 width allowing 0.5 height. The ship weights 400T plus 300T(LOAD) total= 700T whats the amount of water used per lock allowing allowing 0.5 m from the...

I am a woodworker, and am designing a two part magnetic/spring lock for my blanket chest. The first part has 3 master buttons (primary buttons A, B, C), and the second part has 11 secondary buttons (1, 2, 3, ...11). What you do first is choose 1 of the 3 master buttons that opens the first part...

You can lift a zillion-ton ore barge 30 feet like magic, and nothing seems to have done the work. Help me get it.

As I understand it, the rate of rotation of a body is slowed as a consequence of the grater gravitational attraction on the mass displaced by tidal forces as this displacement is pulled forward by the effected bodies rotation thus acting to provide a counter rotational force until tidal lock is...

Homework Statement Digital Combination Lock: To create a circuit that verifies the input from a hexadecimal as 5-A-7 and then lights up an 'Unlocked' LED. (DONE) Bonus Points for: The obvious limitation of this circuit is that the combination cannot be changed. This limitation can be...

im trying to build a cypher-type push-button non-electrical combination lock. the problem is there are no threads/schematics/drawings/specs/diagrams that actually instruct how the push button mechanics work. is there somewhere i could be looking for a schematic?

i am trying to design and build a homemade cylinder-type puzzle lock. I am willing to accept any comments, both negative and positive. the lock is a cylindrical shaft, with a bolt-type actuator mechanism in the center. when the cylinder rotates to the right, the center ejects. when turned to the...

Hello, I have to make a project using AT89c51 microcontroller with a keypad to input a passcode, then compare this passcode to the one stored in ROM of microcontroller and finally operate a lock connected with relay. Keypad is 4*3 Axis. Can someone guide me on how to interface the keypad with...

Hi, There is a 2x2 matrix lock with one key in each cell. A key is nothing but a straight lever which can either be either in vertical or horizontal state. Please see the attached picture. The lock opens only when all the levers are horizontal. However, when you change the state of the lever...

hi, I am interested to know how the lock in amplifier works? It is very commonly seen with oscilloscope, but I fail to grasp the idea behind it? I would appreciate any lecture notes or sites which give clear and precise understanding of it. Thanks

If you have 2 door locks like these the first one is a lot smaller, both locks are installed with the same size screws on the wooden door which of the 2 locks do you think will break first if the door is forced opened.

I love these shows. I know turbo doesn't have cable, so doesn't get them, so thought he might like the free video online. http://www.history.com/video.do?name=LockNLoad Tell me this Warriors guy doesn't make you think of Russ_Watters. http://www.history.com/video.do?name=warriors...

How great would this be for a club house :-p https://www.youtube.com/watch?v=zE5PGeh2K9k

hi all, Just as the topic, I'm thinking a stepless dividing apparatus, for must be stepless, I couldn't lock it by tooth plate such as end-gear, so what machenism can do it? I thought, perhaps I can do a pair of conical surface to realize it, does anyone has done the method? any suggestion...

I have a AC induction motor,i use a strong clamper to lock the motor shaft.Then i switch on the power supply.? So,i want to ask is there the motor will become short circuit? Can i know what is the cause for this malfunction?Is that the motor stator burn out or they still got other reason...

hey guys Well I've searched the net quite a lot but all in vain. Every website comes up with their product rather telling about how to design. Well guys i am a student of 5th semester electronics engineering, have not specifically designed an electromagnet but have studied the basic course for...

I need a help with lock in amplifier. I want to measure third-harmonic voltage from lock in amplifier. I have metal liner on a film on the substrate and I pass ac current through this metal liner which acts both as a heater and a thermometer. I want to calculate the third harmonic voltage from...

Hey! I'm taking my laptop into school to play music, but I want to lock my computer into iTunes so that other people can't get out of it, unless they have a password or something. Anyone got any ideas? I only want people to be able to access iTunes :)