Go Down

Topic: Need Help(providing correct Voltage) (Read 676 times) previous topic - next topic

kylec123

Nov 09, 2011, 04:39 am Last Edit: Nov 09, 2011, 05:36 am by kylec123 Reason: 1
I'm very new with working with electronics like this and need some advice.  

I'm trying to build and RFID door lock(yeah i know..very original) that triggers a 12V electric strike lock.  How  do i provide this power?  As much description as possible would rule.  I'm a noob with the hardware/physical side of this.

CrossRoads

http://www.dipmicro.com/store/DCA-1210

How much current do you need?

You can use arduino to read the RFID, turn on a relay and let the 12V be applied across the strike lock, which I imagine is similar to a solenoid.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

kylec123

"and let the 12V be applied across the strike lock,"

I think this is what i do not know how to do. 

CrossRoads

You're going to have some electromechanical thing that moves out of the way to unlock the door, yes?
Pick a mechanism for that, mount it, and bring out two wires from to connect up to a relay so that current can be run thru it similar to a motor.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

kylec123

Ok, so i need a relay.

This is what im using
http://www.ebay.com/itm/Electric-Strike-Door-Lock-Fail-Secure-NO-Long-plate-/160446497488?pt=LH_DefaultDomain_0&hash=item255b5b42d0#ht_2629wt_754

What relay would you suggest getting?  Obviously a 12V one but i've never messed with one before.  Any help?

CrossRoads

Something like this
http://www.mpja.com/prodinfo.asp?number=18474+RL
5V coil, resistance >=125 ohm so current is 40mA or less (5V/125 ohm = 40 mA)
Contacts that handle 12V & 450mA
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

dc42

Unless you need to isolate the 12v supply from the Arduino supply, I'd use a transistor rather than a relay - it will cost less, consume less power and be more reliable (as long as you remember to include a diode across the coil of the lock).
Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

Go Up
 


Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

Arduino
via Egeo 16
Torino, 10131
Italy