Electronic Lock

digamma · 28th October 2004, 1:38 PM

I'm installing side panels and a lockable door to my rack cabinet (to keep my brother and the olds out). What I really wanted is a snazzy looking keypad lock but I can't find any cheap kits or cheap pre-made ones. So what I thought I'd do is get an electric key lock (Spring return, SPST) and a 12 volt solenoid (pull type) and wire it up to 12vdc and use that as my almighty locking mechanism. Perhaps i'll get 2 solenoids, one for top and botom of the door. I was planning on using an old at PSU to power the locking mechanism and a couple of fans to add some ventilation to the case.

A couple of questions though, the pull type solenoid, does that mean it pulls the pin into the solenoid body? I would ahve thought so, but I just want to check. And most importantly of all, what do people think of the idea? Does anyone else have a different idea? Obviously I could use a straight out mechanical lock, but how boring

. I'd rather go the nerd route and have something novel like this, unless someone has a better idea.

orbitaudio · 28th October 2004, 1:57 PM

Quote:

Originally Posted by digamma

What I really wanted is a snazzy looking keypad lock but I can't find any cheap kits or cheap pre-made ones.

snazzy looking keypad lock kit That one doesn't seem to bad and it seems to have lots of features from what i recall, when i read the article when it was published

Quote:

A couple of questions though, the pull type solenoid, does that mean it pulls the pin into the solenoid body? I would ahve thought so, but I just want to check. And most importantly of all, what do people think of the idea?

Thats the way i would do it. I, like you, assume the pin gets pulled into the solenoid body as well. Although you could probably change this to a push solenoid by changing the polarity to the coil. (it would depend how the particular model u have works though)

Goth · 28th October 2004, 2:37 PM

You can't just reverse the coil polarity because of the mechanical construction of the solenoid, the pin is normally held out by a spring, it is limited as to how far it can go out.

That kit is PIC based, loads of features for cheap!

orbitaudio · 28th October 2004, 2:58 PM

Quote:

Originally Posted by Goth

You can't just reverse the coil polarity because of the mechanical construction of the solenoid, the pin is normally held out by a spring, it is limited as to how far it can go out.

i have seen a few, including some of the ones for sale at jaycar, that aren't held by a spring - they just kinda sit there... these ones are probably made to do both. You have to put ur own spring in if u want it spring loaded. Although these would be handy if someone wanted a push solenoid.

Crootie · 28th October 2004, 7:47 PM

why not try a car central locking kit... they are 12 volt and will run directly from the atx psu plus you get a little remote for it... add the alarm to it and you are laughing...

firestones · 29th October 2004, 12:34 PM

Also put the opening/soleniod driving circuit where it would be easily accessed ie on the outside of rack. IF the circuit did fail you would not be locked out and you would be able to repair it.

pizzaman · 29th October 2004, 12:40 PM

tell them not to open your case!

hlokk · 29th October 2004, 6:22 PM

I recon it would be cool to have a biometric fingerprint scanner on the case. Hook it up to an internal USB (lots of mobos have usbs for the front panel, just dont wire them to the front panel. Then have something which provides a voltage from the parallel port or something, then use a relay for the solenoids (a program and info for switching stuff can be found over at bit-tech).

Would be cool pressing your thumb into it and having it open automaticaly or with a mouse click. (though it does require your computer is on to open it...)

EDIT: on the cheap and small, you could use a dip switch encoder for the switch perhaps

LethalCorpse · 1st November 2004, 10:18 PM

this could be worth a look. You could also use a PCIO kit, so that the case can only be unlocked by software, with passwords etc

orbitaudio · 2nd November 2004, 2:31 PM

Quote:

Originally Posted by LethalCorpse

this could be worth a look.

I've changed my mind from the Keypad idea to the RFID idea. I forgot all about it and it would be awesome (assuming there is not metal between the reciever and transmitter.

u can get little flat rfid tags that u could hide almost anywhere (under your watch even) so NOONE would be able to figure out how to open it!

dean_is_not · 2nd November 2004, 2:38 PM

Whoa, the RFID things sounds so cool. You have to post a video when u do it.

LethalCorpse · 2nd November 2004, 11:23 PM

yeah, the micro tags are awesome - about 15-20mm dia, less than half a mm thick. You could bloody implant them if you wanted to. Then you could put an rfid scanner in your PC, front door, car, garage, bedroom etc and code it to the one in your wrist. very cool.

28th October 2004, 1:38 PM	#1
digamma Member Join Date: Mar 2002 Location: Brisbane, Southside. Posts: 2,428	Electronic Lock I'm installing side panels and a lockable door to my rack cabinet (to keep my brother and the olds out). What I really wanted is a snazzy looking keypad lock but I can't find any cheap kits or cheap pre-made ones. So what I thought I'd do is get an electric key lock (Spring return, SPST) and a 12 volt solenoid (pull type) and wire it up to 12vdc and use that as my almighty locking mechanism. Perhaps i'll get 2 solenoids, one for top and botom of the door. I was planning on using an old at PSU to power the locking mechanism and a couple of fans to add some ventilation to the case. A couple of questions though, the pull type solenoid, does that mean it pulls the pin into the solenoid body? I would ahve thought so, but I just want to check. And most importantly of all, what do people think of the idea? Does anyone else have a different idea? Obviously I could use a straight out mechanical lock, but how boring . I'd rather go the nerd route and have something novel like this, unless someone has a better idea. __________________ The ultimate weakness of violence is that it is a descending spiral. Returning violence with violence only multiplies violence, adding deeper darkness to a night already devoid of stars.

28th October 2004, 7:47 PM	#5
Crootie Member Join Date: Jul 2004 Location: Perth, Western Australia Posts: 325	why not try a car central locking kit... they are 12 volt and will run directly from the atx psu plus you get a little remote for it... add the alarm to it and you are laughing... __________________ to live is to have loved.... but what if you have never loved b4... does that make our existence just a dream

29th October 2004, 6:22 PM	#8
hlokk Member Join Date: Jul 2003 Location: WA Posts: 3,953	I recon it would be cool to have a biometric fingerprint scanner on the case. Hook it up to an internal USB (lots of mobos have usbs for the front panel, just dont wire them to the front panel. Then have something which provides a voltage from the parallel port or something, then use a relay for the solenoids (a program and info for switching stuff can be found over at bit-tech). Would be cool pressing your thumb into it and having it open automaticaly or with a mouse click. (though it does require your computer is on to open it...) EDIT: on the cheap and small, you could use a dip switch encoder for the switch perhaps __________________ Oh, for the love of science! Last edited by hlokk; 29th October 2004 at 6:23 PM.

1st November 2004, 10:18 PM	#9
LethalCorpse Member Join Date: Mar 2003 Location: Harris Park, NSW Posts: 3,799	this could be worth a look. You could also use a PCIO kit, so that the case can only be unlocked by software, with passwords etc __________________ Sig Of Shame removed.

2nd November 2004, 2:38 PM	#11
dean_is_not Member Join Date: Apr 2003 Location: Queensland Posts: 825	Whoa, the RFID things sounds so cool. You have to post a video when u do it. __________________ Nikon D90, Tokina 11-16mm, Nikon 35mm f1.8, Nikon 50mm f1.8, Tamron 17-50, Cactus Triggers, SB600, Yongnuo 460II, shoot through umbrella, and a 1997 Honda Prelude VTi-R. Oh, and a 3 year old Kelpie! flickr

28th October 2004, 2:37 PM	#3
Goth Grumpy Member Join Date: Jun 2002 Location: /dev/null Posts: 9,303	You can't just reverse the coil polarity because of the mechanical construction of the solenoid, the pin is normally held out by a spring, it is limited as to how far it can go out. That kit is PIC based, loads of features for cheap!

29th October 2004, 12:34 PM	#6
firestones Member Join Date: Apr 2003 Location: Brisbane Posts: 300	Also put the opening/soleniod driving circuit where it would be easily accessed ie on the outside of rack. IF the circuit did fail you would not be locked out and you would be able to repair it.

29th October 2004, 12:40 PM	#7
pizzaman Member Join Date: Dec 2001 Posts: 253	tell them not to open your case!

2nd November 2004, 11:23 PM	#12
LethalCorpse Member Join Date: Mar 2003 Location: Harris Park, NSW Posts: 3,799	yeah, the micro tags are awesome - about 15-20mm dia, less than half a mm thick. You could bloody implant them if you wanted to. Then you could put an rfid scanner in your PC, front door, car, garage, bedroom etc and code it to the one in your wrist. very cool. __________________ Sig Of Shame removed.