Magnetic Power connectors

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Sarray

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Hello everyone,

First off, i would like to thank everyone who helped me with my previous post. Being the only electrical engineer at the company can be challenging at times but i am glad i got the guidance i needed and i would like to thank everyone for that.

I currently have a design that i am working on which is very simple and straight forward. However, It contains magnetic power connectors. It is the same technology that is already in the market at a small and large scale for example magnetic ipad chargers. As a matter of fact i also came across some magnetic power connectors that carry AC voltage to power up the RV's...
Anyhow, a magnetic connector is no different than a tyco or a barrel connector the only difference is that in a magnetic connector you have a little more exposure to the energized part of the connector which carries current on both ends. I have tried to contact our UL representative but i haven't heard back yet and have gone through the code UL 962 and UL 65 but i am not able to find any specific regulations pertaining to magnetic power connectors.
Is there anyone on this board who has run into a similar situation? or knows what the speculations are for magnetic power connectors? In addition, the connector will be carrying very low dc voltage ranging from 12v-25v dc, with maximum amperage of 5A.

Thanks all
 
160914-1604 E$DT

I have no idea what you are talking about.

What is a "magnetic power connector"?

"Magnetic power" I would assume has something to do with a magnetic field. So I can envision two magnetic "C" cores, each with a coil, one coil is the primary, and the other coil the secondary. When the cores are separated the magnetic coupling is open and power transfer is nil. When the cores are in appropriate contact, then the magnetic coupling is very good and power can transfer from primary to secondary, and the magnetic connector is closed. However, the open state creates major problems.

The cores and coils can be epoxy encapsulated and present no conductive electrical path. The magnetic field can cause heating and possibly other effects. In an external coil the magnetic field could produce high voltages. A lot of power losses in the open state.

.
 
Gar, think instead of the external power connector of Apple Macbooks, called "MagSafe" design. Instead of a spring loaded pin and sleeve or coaxial connector it uses surface to surface contact held together by the force of a strong magnet. The contact pressure is well controlled and not subject to wear and a strong pull on the cable at any angle will just separate the connector without damage to it or the socket or the cord.
I think that is an example of what the OP is looking at, although I have never seen them used for high power or line voltage.
 
gar said:
160914-1604 E$DT

I have no idea what you are talking about.

What is a "magnetic power connector"?

"Magnetic power" I would assume has something to do with a magnetic field. So I can envision two magnetic "C" cores, each with a coil, one coil is the primary, and the other coil the secondary. When the cores are separated the magnetic coupling is open and power transfer is nil. When the cores are in appropriate contact, then the magnetic coupling is very good and power can transfer from primary to secondary, and the magnetic connector is closed. However, the open state creates major problems.

The cores and coils can be epoxy encapsulated and present no conductive electrical path. The magnetic field can cause heating and possibly other effects. In an external coil the magnetic field could produce high voltages. A lot of power losses in the open state.

.
Click to expand...


Gar, not everything is that technical.:)

It is just a plug and receptacle that is held together with a permanent magnet.
 
I too had never heard it before (not a Mac guy), had to look it up. Interesting. But I for one don't like the idea of permanent magnets being part of a power circuit. What happens if a stray staple or paper clip gets attracted to the magnets? Is Apple relying on the fact that people are not going to be using paper clips and staples much any more?
 
Jraef said:
I too had never heard it before (not a Mac guy), had to look it up. Interesting. But I for one don't like the idea of permanent magnets being part of a power circuit. What happens if a stray staple or paper clip gets attracted to the magnets? Is Apple relying on the fact that people are not going to be using paper clips and staples much any more?
Click to expand...

Yes, and that they are not throwing floppy discs around the vicinity of their computer either.
Also the magnet is in the computer case, not in the cord end, which reduces the opportunity for the paper clip to short out the power supply.
 
GoldDigger said:
Yes, and that they are not throwing floppy discs around the vicinity of their computer either.
Also the magnet is in the computer case, not in the cord end, which reduces the opportunity for the paper clip to short out the power supply.
Click to expand...
Floppy disks? LOL, showing your age! :angel:

My friend's 10yo daughter saw one at my desk a couple of months ago and asked me what it was...
 
Jraef said:
Floppy disks? LOL, showing your age! :angel:

My friend's 10yo daughter saw one at my desk a couple of months ago and asked me what it was...
Click to expand...

If you really want me to show my age, we can go to double sided 8" floppies that you have to remove from the drive and turn over to read the other side.
Or, for that matter punched paper tape on a spool. No magnetic problems there.
Homebrew computers using audio cassette players as high capacity storage.
 
Best example I can think of is for an electric residential countertop deep fryer. Has magnets on the power cord so that if you grab the cord, it breaks away vs sending a gallon of 400* oil all over you. Good idea but the magnets are so weak it barely holds the plug's own weight. Jet skis have a lanyard and breakaway kill switch that is (presumably) 12VDC.

Judging by the look of that fryer cord, I'd say the only regulation is that the wiring is suitable for the environment (oil and heat in that case) and that the contacts are recessed enough so that you can't bridge them with a piece of straight metal or with your fingers. The cord has the 'female' end to accomplish this.

Curious, why do you need a breakaway connection design?
 
Jraef said:
Floppy disks? LOL, showing your age! :angel:

My friend's 10yo daughter saw one at my desk a couple of months ago and asked me what it was...
Click to expand...

Off topic, but I recently watched "a nightmare on elm street" with my 11/yr son......

At the part where the johnny depp's dad takes the phone off the hook because the girl keeps calling their house, my son looked at me and said, "now what does that do?"


Sent from my iPhone using Tapatalk
 
GoldDigger said:
If you really want me to show my age, we can go to double sided 8" floppies...
Click to expand...

I thought you were getting dementia in your old age ;) as there are no 8" floppies, only 5.25 and 3.5....

Turns out I have dementia as I dont remember 8" floppies. lol

eta: and gar, he is talking about breakaway electrical connections, designed to protect the equipment, user, or both in case the device or cord is yanked/moved w/o unplugging. A mechanical/fluid one is on every gas pump in the US, so if you drive off with the nozzle in your tank, you dont break everything in the process.
 
GoldDigger said:
If you really want me to show my age, we can go to double sided 8" floppies that you have to remove from the drive and turn over to read the other side.
Or, for that matter punched paper tape on a spool. No magnetic problems there.
Homebrew computers using audio cassette players as high capacity storage.
Click to expand...

That would be the Sinclair ZX-80. I might still have that. I know I have my Timex-Sinclair 1000; saw it in the storage shed on Sunday.
 
160915-1333 EDT

A different thread title might have helped. Possibly "Magnetically latched electrical connector" or "Magnetically held electrical connector".

.
 
GoldDigger said:
Gar, think instead of the external power connector of Apple Macbooks, called "MagSafe" design. Instead of a spring loaded pin and sleeve or coaxial connector it uses surface to surface contact held together by the force of a strong magnet. The contact pressure is well controlled and not subject to wear and a strong pull on the cable at any angle will just separate the connector without damage to it or the socket or the cord.
I think that is an example of what the OP is looking at, although I have never seen them used for high power or line voltage.
Click to expand...


That is correct!
 
iwire said:
Gar, not everything is that technical.:)

It is just a plug and receptacle that is held together with a permanent magnet.
Click to expand...


I apologize, the title of thread may have been misleading but you are correct. Its nothing more than a male and a female connector, appose to having a plug the magnetic force holds the connection points together and transmits current just like a normal connector.

The unit is designed such that all the wires are installed within a stainless steel tubing and grounded internally. Female magnetic connectors are located at various locations allowing any electrical component with male connector housing to be plugged in any of those locations.

For example, if you have a small lcd screen which has a male connector (magnetic) and female connectors (magnetic) are permanently installed at different locations such as office, house, patio etc you can essentially carry 12"x12" and simply dock it to any of those locations and use the device without having to carry any cords etc..
 
JFletcher said:
Best example I can think of is for an electric residential countertop deep fryer. Has magnets on the power cord so that if you grab the cord, it breaks away vs sending a gallon of 400* oil all over you. Good idea but the magnets are so weak it barely holds the plug's own weight. Jet skis have a lanyard and breakaway kill switch that is (presumably) 12VDC.

Judging by the look of that fryer cord, I'd say the only regulation is that the wiring is suitable for the environment (oil and heat in that case) and that the contacts are recessed enough so that you can't bridge them with a piece of straight metal or with your fingers. The cord has the 'female' end to accomplish this.

Curious, why do you need a breakaway connection design?
Click to expand...



It's to provide the client with an option of either purchasing one set of components that have wires, connectors or plugs
OR
a completely cordless assembly (which isn't necessarily wireless as the tubing contains all the wires) but it appears to be a cordless assembly. All it will require is female connections at fixed locations, can be a desk, a side table, patio, counter-top...etc
 
JFletcher said:
I thought you were getting dementia in your old age ;) as there are no 8" floppies, only 5.25 and 3.5....

Turns out I have dementia as I dont remember 8" floppies. lol

eta: and gar, he is talking about breakaway electrical connections, designed to protect the equipment, user, or both in case the device or cord is yanked/moved w/o unplugging. A mechanical/fluid one is on every gas pump in the US, so if you drive off with the nozzle in your tank, you dont break everything in the process.
Click to expand...


Bingo!
 
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