Electromagnetic Latch

Question

Electromagnetic Latch

DoubleA70 (Mechanical)

(OP)

9 Jan 13 22:49

Hi, I am trying to find information on creating an electromagnetic latch. Allow me to explain using object A and object B. I would like object A to have a permanent magnet that attracted an iron bar on object B. The iron bar would be the core of an electromagnet. When power is applied, I am hoping there is enough of a disruption in the attractive force to separate object A from object B. Does this sound feasible? In searching the internet, I am coming across a lot of questions asking about levitation. This is not what I'm interested in, I simply want to disrupt the attraction long enough for object B to fall away with gravity. Any thoughts?

israelkk (Aerospace) · Answer 1 · 2013-01-10 00:56:40

RE: Electromagnetic Latch

israelkk (Aerospace) 10 Jan 13 00:56

Do patent search for Latch Valve.

MagMike (Materials) · Answer 2 · 2013-01-10 06:57:55

Electromagnetic door latches do exactly what you are asking for.

DRWeig (Electrical) · Answer 3 · 2013-01-10 11:33:01

Have a look at these companies' web sites. Look for electric strikes. Many have detailed descriptions of the innards.

Folger Adam
HES
Securitron
Adams Rite
Bosch
Von Duprin

You'll find a number of others if you google "electric strike" or go thru the ADI online access control catalog. A spring is a lot more common than a permanent magnet to retain the latch in the normally-closed or normally-open position.

Best to you,

Goober Dave

Haven't see the forum policies? Do so now: Forum Policies

Semblence (Electrical) · Answer 4 · 2013-01-10 13:54:48

Yes this would be easy to do. If the latch is utilised on a door, it's probably most expedient to mount the permanent magnet on the door and the electromagnet in the frame to avoid running wires out to the door. The permanent magnet should obviously be oriented either North to North or South to South in relation to the activated electromagnet. A potentiometer can be temporarily put into the circuit of the electromagnet to fine tune the optimum desired power. The resistance in the circuit can then be measured allowing you to replace the potentiometer with a regular resistor of the appropriate value.

DoubleA70 (Mechanical) · Answer 5 · 2013-01-10 16:25:43

Thanks, everyone, for the responses. A door latch is not what I'm after, but the premise is close. I will look into all the sources posted here. Thanks again.

Come Join Us!

Posting Guidelines

Electromagnetic Latch