Inside an eBay electric lock mechanism
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- Опубликовано: 29 авг 2021
- I'm guessing these are designed for automatic release of locker doors like in the Amazon locker system. They operate at 12V and physically push the door open instantly when triggered.
The coils are only rated for brief pulses, and draw such a high current (2-4A) that any microcontroller based circuitry should be designed with separate tracks for the coils and logic from the PSU. To protect the switching transistor against the current spike caused by the collapsing magnetic field when turned off, a diode should be wired across the coil with the band pointing to the positive rail.
The keywords to find these on eBay are:-
electric magnetic door lock
Price will be around £$€7
Here's the manufacturer's website:-
www.doson.com.tw/index.php?mo...
These could also be used as a controlled drop mechanism in some applications.
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Fun fact: I recently completed a project designing the electronics and hardware for a similar thing to Amazon lockers, but for temperature-controlled goods. Literally used these same solenoid locks. I had some test modes to open all lockers (88 per module - they can be chained together) really quickly in sequence. When we were testing, the doors hadn't arrived, so we pushed all the catches into the locks, then started the test mode and it was like a machine-gun, firing the catches across the warehouse 🤣 You have to be careful with them - if they're activated for more than a couple of seconds, they heat up and it jams up the lock, so they're useless. I actually added PTCs in the same way Clive has it here :)
I'm an IT guy in a small russian laundry and for the last 4 years I've been using these made in Russia automated lockers for delivering and taking orders from customers. For cleaners basically. And these at first opened the lock with 10 second duration 12V signal. You may start to understand my problem, the coil was burning out. What made this problem worse is how with the big with original programming, - 12v signal wouldn't cut out after 10 seconds. Lock would work, but only half of the time. Meaning I was left with delightful prospect of having to drop everything and driving 40 minutes to an aggravated customer who's delightfully waiting for their favourite silk dress from the cleaners. It took them over (!!!) 4 YEARS and one of the lockers (not ours) catching on bloody fire for them to fix this bug. Makes my stomach turn only thinking about it.
Also, how do automated lockers which are made from wood and shipped Ikea style to save costs costs sounds to you? Sounds like a great time had by all?
I think I've seen those at Asda for click & collect groceries
Is it possible to get some info on the prpject you were working on ?, interested to know what micro controllers you were using.
10:20 When you mentioned holding a magnet up to the case, I initially thought you meant one of the actual pickup/drop-off lockers and imagined what that would look like. Big Clive skulking around the Amazon lockers with a giant magnet trying to get locker doors to open...🤣🤣🤣
I'm late to this video, but I watched it twice. Each time that unit pinged across the room, I laughed out loud.
Good to know that they are at least hardened against the trivial magnet attack. I'm sure LPL would still find some other quick to perform exploit.
LPL's EMP generator.
OH, THESE ARE THE BANE OF MY EXISTENCE!
I work in small laundry and we've been using automated postbox-like lockers for taking/giving out orders from and to customers. Now, this wouldn't be so bad, but by a weird quirk in Russian regional law, every bit in these chistomats must be made from Russian-made components, even the bloody nails and screws, and this left me with these awful locks, called Prоm1x S М-3О8. They operate on the tightest tolerances, like, if the door frame isn't absolutely 90° to the floor, the lock may get stuck. They are made basically by hand, meaning you have to disassemble and check if they haven't forgot to glue magnets, terminals, little 3d printed plastic strip, have they tighten all the screws; and they are expensive af at almost 50 dollars a pop! Seriously, the only good thing I can think about them, - is what I'm able to send them to repair very easily. What fun, thank for the video, Big Clive!
And most of 20.000 automated postboxes in Russia use normal, made in China locks, it's just I've been stuck with these annoyin almost self made things.
импортозамещение нужно чтобы все страдали.
диды терпели и нам велели
Nice to see someone else who read "Gone with the Blastwave"
@@MRooodddvvv промиксу, производителю тоже трудно. У него мало замков заказывают, а зарплаты, прямые расходы, которые все равно надо платить, остаются.
Видишь, в замке что в видео мало деталей и они литые, и сборка простая. Детали литые, - то есть их просто так не сделаешь из листа металла, как детали в замке Промикс. Но, блин. Взяли бы они китайский замок и скопировали его, нахрен придумывать своё.
@@KrissFliss yeah, I love Kimmo Lemmetti's works, shame he didn't release it in book form. He's very Finnish and kind of depressed, I got that feeling from his Twitter.
This may be the first time I've ever had intimate experience with something, before Clive did a teardown on one!
We use these extensively in the escape room industry. Tiny, dirt cheap, consumes no power while idle (unlike a mag lock, which we also use extensively).
Fun fact, the 12v units will operate splendidly at 24v. I run them on a NPN output from my PLC's with a 100ms timed coil output.
My standard procedure with these is to use the switch as a monitor input on the PLC, allowing the game master to see on the HMI if the player has successfully completed whatever puzzle the lock is attached to and the status of the door / prop / lid / whatever. I use the same input to monitor if the door is closed before the game is reset. IE, player closes door while the game is running, the door immediately pops back open so they can't lock themselves out of a box that they may still need to get in to.
As long as you stay within the technical limitations of them, they're very, very reliable, very robust little locks!
We use them in exactly the same manner :P Great locks indeed!
If i am getting this right you mean that switch could act as the sensor to westher the door is open or not right ?
thought this was a lockpickinglawyer video for a second there!
I just want to see a whole wall of those lockers all burst open at once. I'd imagine it would be quite loud. Ideally as part of a James Bond-esque heist.
I somehow expected this to be an LPL video lol
Me too
Just a thanks from across the pond. We appreciate your humor and the Department of Villiany
send it to LPL for an exploit, then design it better and send the new one back. Would be an epic series.
Lol .. yeah was just going to say 'LPL noting vulnerabilites'.
Was about to suggest the same! :D
Only thing I can think of is magnet, which Clive tested and should be safe from with the steel case, and impact, which it should be safe from unless you can pick up and drop the entire bank of lockers. You could get a bit of something in to push up the latch but these are going to be mounted inside the lockers so they'll be protected from that too.
Came looking for comments about Lockpicker Lawyer. Was not disappointed!
They would be great for secret doors, you just use your phone and the door in your wall opens, no handles on the outside just one for closing it when you are inside, vanishing act, Thank you Clive I will now use one of them in my books.
But the noise. ..
@@snakezdewiggle6084 one can think of a wax motor instead if they need silence. ;D
@@jkobain too slow.
@@plainedgedsaw1694 yeah, I know! But sometimes it can be not only an acceptable solution, but also exactly the thing you needed.
Or someone else did.
Why a phone and not a voice pattern recognition. "Open Sesame" or another passphrase said near the door in a particular voice. Recognized by a computer and microphone entirely in the hidden room, not some link to a remote cloud company. Inside there should be switches to disable the automation and open based entirely on human decision.
Another way of triggering the release would be to discharge a capacitor into the coil. This would reduce peak supply current and would limit the standing current if it was left energised.
Some one needs to tell this to lock picking lawyer.
@@rogerlague1520 It's not an attack, it's a way to run the entire thing from a 1A power supply, except for that one capacitor charged by a boost converter.
@@johndododoe1411 just having fun. Ever had any fun with very large hvac capacitors. They do amazing things to locks and many other of things. Maybe Clive can do something about this.
12V@2A for about 0.1s needs 2.4J of energy, at 12V, we need a capacitor of 33.3mF for this. We probably need to exeed the maxium volage rating in the coild if w want to use feasible capacitor sizes
@@FerrybigGaming It's a big cabinet, just put in 20 2200μF 16V rated capacitors with the usual tolerance. Doesn't have to be low ESR either.
6:57 Oh, I've been there, our manufacturing dealer had an error where the 12v signal didn't cut out after 10 seconds, and it was burning coil out. Always delightful, when you have a client call from locker, eager to receive their favourite silk dress from the cleaners, - and you realise what the bloody lock is not working, not opening. And you have to drop everything and drive 40 minutes to delightful locker to replace the "lovely" and "good" lock.
AND IT TOOK OVER A 4 YEARS, AND ONE OF THE LOCKERS CATCHING UP ON FIRE FOR THEM TO PUSH UPDATE WHICH WOULD 100% PREVENT THIS FROM HAPPENING.
I still love these lockers, whatever the costs
Thanks as always Clive! This is exactly why I love taking stuff to bits, thanks for a fuller understanding!
Got a bit of a thing for locks of all kinds especially electric and electronic ones, so this vid is right up my street. 👍
Amazon Lockers are highly useful for those of us living vanlife. Cool video 👍🏼
And for those of us who travel with work.
Useful for an outside parcel box. Leave ot open for the postie to lock , use the switch to indicate post received....
That's fine if all parcels come by the same carrier. That's not what happens here!
I live in an apartment complex where they have these Amazon parcel lockers. You can open them via Bluetooth or by keying in a code. I'd imagine they use the same sort of mechanisms you described in this video! The more you know! Thanks for the vid.
You can almost see the action if slow the video down to 0.25 speed. Great explanation of the inner workings.
Finally, Clive posted. My day can begin.
Loving the change in content. Sorry Clive I was getting burnt out on ozone 😁
*NEVER!*
I'm not finished with ozone yet, but I'm giving you all a break.
Hey, Cool! That's a good way to release a package from a drone, just use a string instead of the hasp.
I needed to pulse a counter solenoid and I didn't want to, like you said, have a chance of full current constantly through the solenoid. So I put a 1000 uF cap paralleled with a bleeder resistor in series with the solenoid coil. Turn the transistor on and the cap charges up through the solenoid, actuating the solenoid. After the cap is charged, the bleeder resistor conducts many times less than the actuating current. Then the transistor turns off, the bleeder resistor discharges the cap and it's ready for the next pulse. This also works good for button pressing nuts who like to take out their obsessive-compulsive behavior on pressing the button. If they don't wait for 5 or 10 seconds, the solenoid won't activate. 😂😂
Great video and interesting item!
This video title would have made a great Sean Lock stand up DVD title 🙁
I've seen two wire versions that wire the door closed switch in series with the coil - if the output goes faulty and goes high the door opens and automatically disconnects the coil so it can't overheat .
Checking to see if the door is closed is done by passing a very small current through the circuit to see if a coil is present, this is easy nowadays because microcontrollers can monitor there outputs to ensure they are doing what they are told.
That could be helpful but it wouldn't be a catch-all solution. If the door is prevented from opening it would still burn out the solenoids.
I am also a big fan of Amazon lockers - a great convenience!
Little known thing with Amazon lockers, each compartment has a set of infrared beams to detect that something is in there, I found out because I started leaving small presents (bags of sweets) for the amazon delivery person but the locker complained that I hadn't picked my package up when I shut the door again.
That's interesting to know.
Huh, that's pretty neat
Most car doors I've looked at use the same hook and shackle arrangement with the only real difference being the trigger plate is diconnected from the handle (which actuates the same way the solenoid does) by the lock.
You can get 3V versions of these that use "muscle wires" that are surprisingly good
Uhm, could you elaborate, please? I tried googling it and came up with nothing. What do you or in Google to get these "muscle wire" locks? Maybe, you can tell me a brand for these, please?
These sound very interesting, I would love to see more of them
The protection diode is known by various names, including ‘back EMF diode’, ‘spark quench diode’ (especially if a switch or relay contact is controlling the coil), as well as ‘flyback diode’.
Also called Freewheel diode or Snubber diode.
Hey Clive... You can also wire the microswitch in series with the coil. Thar way the circuit is broken the instant the hasp releases and stopping overload. Will reduce current draw too as the solenoid will only energise for a split second.
You should send that to the Lock Picking Lawyer. I imagine that he may have some tricks to get that open without dismantling it, probably either by rapping it or getting a fairly large neodymium magnet in the right spot.
pretty sure it would just open if he looked at it sideways
It looks like it would be vulnerable to a locking bolt attack, just get a probe up to the bar actuated by the solenoid, push up, and it should pop right open. Probably a traveller hook or maybe a street sweeper bristle should do it.
@@yourcurtainsareugly How would that be done when the entire thing is behind the steel door, flat inside the wall between compartments. With the hinges similarly behind the other side of the door, mechanical attacks are limited to pushing and pulling the hasp, and magnets can only be placed on that side, or maybe on top of the entire cabinet. Angle grinder attacks seem more effective. Of cause, hacking the control computer for the entire cabinet or finding a maintenance password would be game over.
Exactly what i was thinking. LPL and DeviantOllam have really influenced my thinking. Locking an innocent BigClive Video when there´s the random thought: what would happen if i out a Neodym Magnet right next to it.
@yourcurtainsareugly: i think a neodym magnet would be far easier and as far as i can think on such lockers theres no real space for an attack like that
@@johndododoe1411 That's what I think as well. If the electronics are EMP safe, I think this is almost perfect security if done properly. You should be able to design a door in a way where physical access to the mechanism is almost impossible. Also these can be made very sturdy. Most likely crowbar / angle grinder would be the easiest way in.
The release cam is very similar to what they used on SOME old car doors back in the early 50's and 60's.
That's a lot of current to pass for releasing what looks like a fairly simple spring mechanism! The lock looks quite safe when installed in a storage locker configuration, all these comments about rapping/tapping it... seems quite hard when it's mounted in a storage case.
I've had a few for a while in a remote catapult application, they're designed to hold 150kg so quite a bit really
Yeah I was immediately thinking about how to pick one the moment Clive opened it but as you mentioned it all comes down to how you mount it, if the door has a lip and it's tight and sturdy enough it would be pretty hard to open cleanly
They seem to subcontract and offer even like Aliexpress shipping to PO-like boxes of various local delivery services.
Sometimes these services are just great, while others send your parcel hell knows where and ignore your complaints completely.
My latest purchase was promised "shipped from the EU, no tax problems", but was FedEx-ed from the US to a convenience store 1 km away.
Some of these can be forced open with enough pulling force, some you can pull the door and whack it with a hammer to make it jump open. But most lockers they don't give you anywhere to pull and get enough force for either method, so combined with the resistance to magnetic manipulation, they're fairly hard to force open -- most thieves would probably just pry the door open with a crowbar and break it or otherwise smash their way in before they could really make one of these misfire or otherwise open.
I understand the Amazon idea with the lockers having the central control, pulse the right one and the locker kicks open. But I've got this wild idea of taking an existing design of lockers, and modifying the doors so each one has a cheep RFID reader, and one of these. Detach the entire door when power is low and put a new one back in place.
Russian grocery delivery service Utkonos uses this design of locks and lockers. Lockers look like your typical cupboard, the lock goes on the door and has NFC reader built in. Whole system looks very cheap and I think the system is meant for couriers, not civilian customers.
I was about to say that they would be good for a secret door in your house to hide a safe or if built strong and hidden well to actually be a safe in itself. Maybe if the house is built right to be a secret passage with spyholes for all types of mischief.
There is a large bank of Amazon lockers at a university hall of residence about half a mile from here. Presumably it's very popular with the students.
Much easier to have a central place for the delivery person than to have the poor fella wandering the campus trying to find the right dorm (if even allowed)
When I was at uni we had one central place that took deliveries, but it only opened to the students to collect their post for an hour or so per day. We'd have loved to have Amazon lockers instead.
Because prime is cheap when you have university card.
But Amazon in EU is an expensive garbage that only exists because of fast shipping.
@@Yrouel86 a
I did wonder how they got the door to swing open. The only issue I have with those lockboxes is the criminals in the area know you are going to collect goods and dependant on where the lockboxes are they may be waiting, they would not know what they were stealing though.
Thank you, Clive. They seem fairly robust and probably difficult to defeat except with extreme force
Yeah, i'll just stay away from anything in a big city, or crowded area....
Heck, in Seattle you can't even go to the courthouse (yes, that court) without the threat of being robbed.
Applying the same logic, shouldn't ATMs be crowded with criminals? Like in that Steve Martin film "L.A. Story"?
@@mojoblues66 actually there are issues with ATM's. Number of them have been detonated at night, pulled by car or by stolen excavator.
Clive should do a self defense segment on what Brits may use here in the US in Indiana ( and most other states except the liberal ones ) we have pistol carry permits by federal law you cannot carry in the post office . But out here in the country they do not enforce it most open carry too the bad guys seem to know this we also have laws that prevent banning carry in most public places we seldom have a Robbery also we have the stand your ground law . Sadly in the UK you cannot fight back like we can .
@@johnsiders7819 you'd have nothing to "fight back" against if you fixed your disgustingly abusive society
Huh, that is EXACTLY an electric crossbow trigger (or roman siege machine for that matter, just smaller scale). The classic whammo powermaster uses a falling plate lock derived from this, but this exact shape is known historically around the world for well over a thousand years! I wonder how strong the sear plate on this is? heh
Very nice to know. Apparently Russian manufacturer of electric locks Promix doesn't know that, because design of locks I'm stuck with using is bloody awful. They don't work when door pressured on them too hard, they don't work when door presses on them too light, they don't work when the door is not at perfect 90° angle to the floor...
Locks in the video use "door pusher" which is not connected to mechanism of actual lock, - this is how you know they are good, robust locks. Unfortunately, our lock dealer, Promix, made a decision to invent a wheel with their lock design, and I'm stuck with in-robust garbage.
Sorry for my English, I can write more coherently, I'm very tired
It is one of those latches that got Jet Li in trouble!!
"I tried to open it with a magnet"
Of course you did, Clive.
That is damn close to the design of the AR trigger group
They would make a good a electronic crossbow trigger mechanism.
That's an interesting idea.
Clive,that sounds like a cool idea, switch,crossbow, phone app 🤔 feckin great security system 😁
Remote activated crossbow bolt launcher? 🤣 Cheap security system!
Or it pops the latch on the kennel door and releases the Dobermans.
@@tncorgi92 Smither's will be out of a job then 🤣
I've always wondered how those worked. Would be really neat if you made something with that at a later date🤔
I can confirm that all the issues you mention are real. Cash drawer release solenoids are very similar and yes they get VERY hot if a fault leaves them energised. Sometimes the coil swells up and the armature jams, hopefully in the open position.
Problem with that design is that if they fail, they fail secure (which means the lock stays locked). A convenience that suddenly becomes a significant head ache, especially since the lock will usually be mounted inside the door.
Oh, I've been servicing such problems for 4 years already. Our automated lockers, used specially for drycleaning orders, use bad quality locks, and they stopped opening doors after a few months of working. Every few months, kind of in a way BC described at 6:57
These are the name of my existence, my eye started twitching as soon as I saw that thumbnail
We use hundreds for more than 5 years now and not a single one has failed.
We do have single hole and tool planned so we could push the latch through the (not yet drilled) tiny hole if we really need to, but I guess crowbar would work too... 😁
@@zlac you should consider yourself lucky not having to deal with this. We use lockers which were built with having lowest price in mind, they are made from wood, - so no service compartment for locks. Meaning you can't get to the hole on the back of the lock to open it in case of emergency
@@zlac that's how they SHOULD work. And our manufacturers wonders, "hey, why don't ppl buy these in droves?" and "hey, why do ppl buy these lockers, install them, use them for a month and then scrap them?"
That latch design is similar to automotive door latches on a slightly smaller scale. Being solenoid operated this could work on the custom cars that have had their door handles shaved.
Yeah I've learned the hard way that it's not so great if the only mechanism to open part of your car is electrical... Try having a dead battery and your jumper cables are in the trunk which has no keyhole and can only be opened with a solenoid controlled by the computer...
Simple but good
Thanks for sharing
My van is an ex border agency van and had cells using those locks so I should imagine they are quite secure!
You'd be surprised how shoddy some law enforcement equipment is. Watch Lockpicking Lawyer's videos on some of the gun locks used in patrol cars. Ridiculously easy to defeat.
They don't really need to be that secure for that sort of use case.
Unlike the insecure border then!
@@mfx1 Really? You don't think that the lock on a gun inside a patrol car needs a decent lock? All someone would have to do is bust the window on an unattended car and easily remove the gun. Those cars are quite often left unattended while an officer is away from the car (such as going into a business or home to investigate a disturbance).
@@mattelder1971 relax, I think he meant the use case of a holding cell inside a border protection van.
Clive mentions Dave's coverage of fly-back diodes. Then (unintentionally or not) how LPL or Bosnian Bill might try an attack with magnets to get the lock open.
Nice how the manufacturer laid everything inside the lock so clearly, making Clive's job of explaining it easier.
I suspect the Lockpicking Lawyer would have that open with some implement in less than a second.
He'd probably have a live pigmy goat lick it.
He can't. It's behind a metal door. No outside access.
As it would be buried inside something else, the security of whatever its inside determines how easy/hard it is to get into. Additionally any sort of EMP device would likely be useless against the lock itself as the coil has quite a low impedance. Your only hope would be either a crowbar, or possibly getting whatever driving it to fail short-circuit so it opens.
@@mysock351C I wonder if a firefighter's haligan bar would make short work of the job.
Actuate you damn you! That's why I'm here! LOL
WOO!
Good Monday morning to you sir from Wellington Somerset
Awesome big Clive
Is there one on the door to your Disco Dungeon? 👍 😂
Or, did you add it to Ralphy's whiskey cabinet? 👍
Hello from Russia. My Laundry Lockers maker finally switched to Chinese locks instead of Russian made ones, thank God
I guessed the switch killed power to the solenoid after it had fired.
“I got a new big mofo… ” I am interested.
very informative video sir !
I must remember to hit that like button!
Low duty cycle.
So what you're saying is that you're going to make a 555 circuit and a relay to activate it over and over to piss it off and see how it fails and how long it takes? Or are you going full PhotonicInduction and giving it a full unpulsed voltage and ramping it up until it bursts?
What do you mean by "low duty cycle", what they are meant for low number of "openings"?
I use kind of same locks in automated drycleaning lockers our company uses. And the locks our dealers uses to make lockers, - are bloody awful, kind of Ork technology. I hate them, as they don't open the door if you just look at them funny. I always have a supply of locks at hand, because they surely stop working every few months, and the only repair is to send them to manufacturer for repair. Prоm1x SМ-3О8, they are called.
Thank you for your comment, sorry for not leaving comment in good English, I'm just very tired.
@@KOTYAR1 low duty cycle basically means they can't be powered too often within a set period of time. So if a machine had 100% duty cycle it can run continuously. An example of a duty cycle thing might be like a cheaper welder. If its a 30% duty cycle welder, within a given 10 minutes it could operate for 3 of them continuously. A small, high power solenoid like this might be a much lower duty cycle than that. Like you could only open it once every couple minutes
@@WyattUTFT Really you also need to know the pulse length too. One hour on, nine hours off is also 10%.
@@KOTYAR1 10% duty cycle in this case means no more than a half second power pulse every minute, as that CCA wound coil will otherwise turn into a black mess. For the price that coil wire will be CCA, not enamelled copper, and will fail at under 130C coil temperature.
Snazzy. Now I want to build a secret door someplace just so I can use one!
Put one like that in fridge.
Seems like a good match for all 7 outputs of a ULN2003 in parallel.
For short duty cycle it may be able to control several of the 2A units directly. But the combined chip current restriction would not allow use with the smaller higher current lock.
Amazon Locker.The Lock Picking Lawyer is gonna get a lot of free stuff.
A simple but clever device and it works well. I'm thinking that it could be attached to something that would enable it to fire a projectile some distance depending on the spring strength but I bet it could be adapted . 👍👍👍
You can run the coil through the switch... That would de-energize the coil once the solenoid triggers (unless someone holds the door shut)
people are basically stupid enough to destroy everything.
Maybe attach one to the ceiling and hang a balloon of water from it. Prank time. 😊
Maybe put the switch in series with the solenoid to prevent burning out the solenoid?
The schematic looks like an Easter Island Head!
I wonder how much these have in common with more modern apartment buildings' access control systems. I also wonder if lockpickinglawyer knows of any interesting defeats on them that don't involve cutting the power.
They don't take a great deal of force to pry open, in most cases.
Cutting the power wouldn't help much either...
@@stepheneyles2198 Unlike buildings where exits must work in case of disaster, thus making forced power cuts a way to weaken security.
The LockPickingLawyer has a whole series of videos on keypad/RFID access control systems, with exploits ranging from a Swiss Army knife through a magnet to a parasite signal reader.
These things can also be useful when building escape rooms or other games that require hidden compartments and such. Never use for doors though because they are fail-closed.
Thanks for the tips on how to secure them against damage by sustained operation! If you don't follow those, you'll have to replace the lock, but the lock is behind a now forever closed door... don't ask me how I know.
Ok, out with it. How do you know?
@@ragetist The answer is behind the door.
Another trick for solenoids similar to your capacitor pulse thing is you charge a capacitor up to quite a high voltage and then dump that across the coil, that gives very fast powerful operation and prevents burnout if the circuit latches.
ruclips.net/video/vXho3X5UXOo/видео.html This used cap discharge with rotary solenoids.
That's a smart way to defeat powerful magnet "attacks"
LockPickingLawyer has entered the chat
I recently worked on a project that uses similar locks. But the ones I used had motors inside, not a solenoid. It was possible to operate it for "half a turn" if you were quick enough.
I think they didnt draw as much current as the ones you have.
It's really annoying that the term "flyback" has become interchangeable with "back-EMF" when really it is has a specific meaning in the context of CRT deflection.
The correct terminology is freewheeling diode.
@@cambridgemart2075 Yes sir. Flyback, and free-wheeling are 2 separate applications
Lock Pivoting Lektrician
One very very interesting fact about those is that they are some of the only latches that easily unlatch under force, so if you have a door that you need to reaaaally push to close, other latches youd need to push to open. Not this type! The solenoids also pull a ton of current, I have one that pulls 2 A from 12 V, that's 24 W! These solenoids can become bbq flavored real fast
Something else: about the reverse polarity diode accross the solenoid, it is a good way but there is a much better one, which is placing a reverse biased "TVS" type diode in parallel with the switch. What happens then is that as soon as the Transistor stops the current, the solenoid will start building up voltage and when it reaches the reverse breakdown of the TVS diode, it'll conduct. This is better because it also stops the wire impedance from causing damage, especially that a cabinet full of these could be pretty large. For my 12 V solenoid, im using a 15 V TVS diode, which means that the most that the Transistor will ever see is 15 V, while placing a normal diode parallel to the solenoid guarantees nothing
Tell me about it. I've been stuck with Russian made locks for the latest 4 years. They don't work when door pushes on them too hard, when there's no gap between the door and the frame, they don't bloody open when the door is too "free", they don't lock. They don't open, if the door isn't 100% horizontal. They also dont open if the customer tried to open the door, thus "softlocking" the lock, meaning it wont open even if you send 12 v to it again. They did burn after 12v, our manufacturer changed the algorithm of opening instead of sending 12v to lock no matter what, they now open with 100ms pulse until the lock is opened. We use them in drycleaners, to take orders from and in from customers.
@@KOTYAR1 hmm, in your case I feel like experimenting with a different latch might work
Alternatively, put the latch on a platform that has some freedom to move laterally, that might help it self align
About them not releasing when there's force, have you tried lubricant? Also, debur and smoothen the internal pieces, that might solve it
There's nothing you cant diy a solution for ;)
So awesome
It is nice that they included the micro switch so that a pulse drive circuit is not required, you could hold the coil power ON as long as you like if the coil is in series with the N.C. micro switch.
Good design, looks very reliable . Thank for sharing with us.
I would not pass the solenoid current through that littie switch. It's there to tell you the door has been latched closed.
@@Monkeh616 Most micro switched are rated for much higher current than the 2 to 3 amps at 12 volts of the solenoid. Normally they are in the 12 to 15 amp range.
@@Robothut Not for DC they're not.. It's a status contact. It even says so in the datasheet.
@@Monkeh616 I am fully aware they are using it as a status switch. Thats not the point. The micros switches give there rating for both AC and DC and high voltages and low. I have been using them for over 50 years.
@@Robothut And as always with these claims, I'm very interested to see the low-cost subminature microswitch with the 10A DC rating which you think they've used.
Yes, you can get switches you can do that with. No, a dirt cheap lock actuator from China isn't using one.
The ikea rfid locks are interesting inside too.
A 1N4148 or a fast Schottky diode is good as a flyback diode.
A 1N400x is too slow. Maybe a UF400x, but a cheap simple 1N4148 holds the power spike too.
1N4148 will fry there, your diode must be rated for the current draw of the lock, or else you will kill the diode short circuit with the repeated pulses that run it at absolute maximum (and a little more) single pulse current. You need an 1N5401 or better diode, as the 1N4148 is really only rated to carry 100mA from most vendors, though some specify them at 200mA as well.
Washing machine - we had a new board put in as it stopped responding to the power button. The new board needed programming. I immediately spotted new styles of operation of the washer. Some years later I discovered the fast spin rinse cycles never ended. It fills with water rinses, empties and repeats ad infinitum !
That sounds like it might have been loaded with the wrong software.
@@bigclivedotcom Or my thought was buggy software !
@@millomweb @pmailkeey Oh, it's nice to meet another OPL laundry engineer in the wild! That sounds like the problem with the controller and is low-key terryfiing. So where are you from?
@@KOTYAR1 North west England - where I can't get medication !
Damn these would have been so great back in the day when hidden doors where of importance.. good to know they exist if the need arise again i guess. :)
I have a small book that showed how to build a similar (but different) mechanism. It also has such fun things as adding intermittent wipers to your car. Yes, it's that old.
Pretty sure electromagnetic locks have been around for a long time
@@smeezekitty I have seen a Pyramid in Egypt that had one !
Some time ago I found three cash register drawers that were being tossed out by a shop, one was too big so I just kept the solenoid and it had a very similar mechanism with the drawer kept in place with a hook with a decent spring behind so when it's commanded to open (24V) the drawer itself is pushed out quite a bit.
Fun fact, apparently the drawer is controlled by the receipt printer and connected to it with an RJ45 ish connector and you can tell it to open before or after printing
I have one of those drawers here, and the receipt printer with its drawer transistor too.
@@bigclivedotcom I recently found five BIG rolls of 80mm thermal paper discarded by a bank (I don't know why do they have an expiry date?) so I acquired a cheap thermal printer to play with and that's how I'm finding out all sorts of things related to the POS world.
Like some time ago I also found a card reader with a weird USBish connector which is in fact PoweredUSB.
(I find all these things because I live very close to the main commercial street and the shops bring out their garbage around 20:00 so I often go for a walk to see if anything interesting pops out)
It is a law, like Moore's Law, that in any video about locks, the comments will mention the Lock Picking Lawer.
Even though there are many RUclips channels like HelpfulLockPicker, LockNoob, lock picka 69, ...
I installed a cheapie ebay electric door strike last week.. similarly designed mechanism but it only draws 250mA. 2.5A seems quite high, to be sending over the distance the lock may be from the controller.
You turning into the lock picking lawyer? 🤣
Great content as usual
Long before amazon lockers were even a thought, Car door poppers were a thing when tuning meant shaving the door handles on a polo xD oh the tuning before even F&F was a thing... XD
I thought tuning was adjusting the trigger angle of the spark solenoid and the valves to get maximum output at a chosen rpm.
@@johndododoe1411 I'm talking about the transition period xD between adjusting spark timing by turning the cap and having 1000 hp supras, the time where Polo G40 and Audi A3 got Lambo scissor doors, shaved door handles, FIAT Unos with subwoofers that weigh as much as the car etc.
@@Tarex_ But shaving the door handles wasn't the tuning, it was just part of weight and aerodynamic improvements.
@@johndododoe1411 and the Chrome wheels were for more grip and red neon underglow for 20 horses because stickers would counteract the weight reduction..
The Amazon lockers near my house are in a Amazon shipping facility. I've on several occasions arrived and had to wait for an employee to put my package in the locker in order for me to retrieve it. The lockers are also only available during business hours, so they can't be used for after hours pickups or returns.
Most 7/11s in my area have Amazon lockers that are available 24/7
Why put the screw into the latch arm??? Can't be to adjust tension because one end of the spring rests against the case and the other end hooks around the nose of the arm.
Maybe to ease in assembly?
If the switch was put in series with the coil it would not matter how long the pulse is as long as it is long enough to un-latch the system. That way the coil can only energize if the latch is hooked [door closed] then as soon as it is un-latched by the solenoid the current is interrupted immediately. With separate pigtail connections, the switch can register to a door control board as to whether the door is open or not. Maybe connect the 0V rail through the switch to the source pin of an N Channel MOSFET. This way a logic level signal could tell the door to open, which would only activate if the door is already shut.
Fun contemplating potential engineering designs and reasons.
Reminds me of pin ball machines. Where like the flipper solenoids are really strong but would burn quickly. But they have a switch that changes from the (firing coil) to the hold coil since obviously much less energy needed to hold the solenoid once it's traveled all the way.
content free comment to drive engagement for my favorite channels
Intention free comment, because I'm tired and sleepy af at my job
Simplified lock operating the same way as most car locks. If you have car morgue nearby or cheap used car parts delivery you can choose from a variety of forms and sizes of more riliable and sophisticated 12V car locks with solenoid, brushed or brushless motor actuator with self operating contact encoder for the same price.
I work with residual gas analysers that's a whole different interesting subject
Try EM Induction to trip the solenoid.
that would make a great electrical crossbow trigger