Patent Application
20150093920
Most laptops use a barrel style connector system to convey operating power from a power supply to the laptop. The cable-end plug is inserted into a socket on the laptop, and is held there by friction. Connectors have also been made which use magnetism to hold a cable connector to a corresponding connector on the laptop. This is gaining popularity for use with notebook-type computers and “tablets”.
When a magnet is heated past a certain temperature, the Curie temperature, it begins to lose its magnetism, and this loss of magnetism is irreversible. That is, merely cooling the magnet below the Curie temperature does not restore the magnetism. Printed circuit boards often include surface mount technology (SMT) components and other components. These components are soldered to the board by, for example, wave-soldering or reflow-soldering operations. During these operations the components may be subjected to high soldering temperatures and/or longer durations of higher temperatures. This can result in loss of magnetism of the magnets in the connectors.
To avoid this loss of magnetism, the magnetic connectors are frequently hand- soldered to the PC board after other soldering operations have been completed. Hand-soldering operations, however, are time-consuming and labor intensive and, therefore, are expensive. Also, because they are performed by humans rather than machines, the quality of hand-soldering operations is subject to variations which can lead to poor or weak solder connections, poor or failed electrical connections, and even damage to the PC board, such as but not limited to a conductor trace on a PC board separating from the PC board due to excessive heating.
It is with respect to these considerations and others that the disclosure made herein is presented.
A heat resistant magnetic electrical connector is described. The heat resistant magnetic connector includes a body formed from an electrically insulating material, the entire body being tolerant of soldering temperatures associated with wave- or reflow-soldering the heat resistant magnetic electrical connector to a printed circuit board, first and second electrical conductors extending through the body, and a magnet assembly for insertion into a receiving area on a back side of the body after the first and second electrical conductors have been wave- or reflow-soldered to a printed circuit board. The body may include first and second plugs which extend from a face of the body, the first plug being located toward a first end of the face and having a first width, the second plug being located toward a second, opposite end of the face and having a second, different width. The body may also include retainers for securing the magnet assembly in the body after the first and second electrical conductors have been wave- or reflow-soldered to a printed circuit board. The body may also include first and second openings positioned between the first and second plugs and extending from the face through the body to the receiving area. The magnet assembly may have a first end and a second end, the first end having first and second extensions, the first and second extensions extending into the first and second openings. The first and second electrical conductors may extend through the body and form exposed first and second electrical contacts, respectively, forward of the face, and form first and second connector pins, respectively, at respective first and second predetermined locations other than the face or forward of the face, such as on the back or the bottom of the body. The first and second connector pins are configured for being wave- or reflow-soldered to conductors on the printed circuit board.
Another magnetic electrical connector is also described. The magnetic electrical connector has a body formed from an electrically insulating material, the entire body being tolerant of wave- or reflow-soldering temperatures, first and second electrical conductors extending through the body, and a strike plate of a material which is attracted to, or which attracts, a magnet. The body may include a face, first and second sockets recessed in the face, and a recessed area in the face between the first and second sockets. The first socket may be located toward a first end of the face and have a first width, and the second socket may be located toward a second, opposite end of the face and have a second, different width. The first and second electrical conductors may form exposed first and second electrical contacts, respectively, at the face and form first and second connector pins, respectively, at respective first and second predetermined locations not on the face, such as on the back of the body. The first and second connector pins are configured for being wave- or reflow-soldered to electrical wires in a connecting cable. The strike plate may be positioned in the recessed area.
A method for manufacturing a heat resistant magnetic electrical connector is also described. The method includes providing a body formed from an electrically insulating material which is tolerant of soldering temperatures associated with wave- or reflow-soldering the heat resistant magnetic electrical connector to a printed circuit board, inserting first and second electrical conductors into the body, and providing a magnet assembly for insertion into a receiving area in the back side of the body after the first and second electrical conductors have been wave- or reflow-soldered to a printed circuit board. The body may include first and second plugs which extend from a face of the body and first and second openings. The first plug may be located toward a first end of the face and have a first width, the second plug may be located toward a second, opposite end of the face and have a second, different width. The first and second openings may be positioned between the first and second plugs and extend from the face through the body to the receiving area. The magnet assembly may have a first end and a second end, the first end having first and second extensions, and the first and second extensions may extend into the first and second openings. The body may also include retainers for holding the magnet assembly at least partially within the receiving area. The first and second electrical conductors extend through the body and form exposed first and second electrical contacts, respectively, forward of the face and form first and second connector pins, respectively, at respective first and second predetermined locations not on the face or forward of the face, such as on the back or the bottom of the connector. The first and second connector pins are configured for being wave- or reflow-soldered to conductors on the printed circuit board.
A method of installing a heat resistant magnetic electrical connector on a printed circuit board is also described. The method includes positioning an electrical connector on a printed circuit board, wave- or reflow-soldering the electrical connector to the printed circuit board, and then installing a magnet into a receiving area on a back side of the electrical connector. The magnet may be installed by installing a magnet assembly which comprises a magnet and magnetic flux plates such that an end of each magnetic flux plate extends from a face of the electrical connector.
The board connector 115 has a body 116, which has plugs or bosses 120A, 120B, electrical connectors 120A1, 120A2, 120B1, magnetic flux plates 125A, 125B, and a magnet (#130 of
In an embodiment, the plugs 120A, 120B preferably, but not necessarily, have a height of approximately 2 mm, a length of approximately 2 to 4 mm, and a depth of approximately 1.55 mm. The length of a plug 120 (120A, 120B) is determined primarily by the number and size of electrical contacts in the plug, the distance between electrical contacts being appropriate to prevent arcing between the contacts in view of the expected voltages on the contacts. The sockets (220A, 220B of
It is preferred, for economy of material and space, that the plugs 120A, 120B and sockets 220A, 220B have electrical contacts therein and also serve to effect proper orientation of the connectors. In an alternative embodiment, some plugs and sockets may be used only for orientation and may not have electrical contacts therein, and other plugs and sockets have the electrical contacts but are not configured to provide for orientation.
By way of example, and not of limitation, the connector 115 may have a depth of 11.3 mm including the magnet assembly 122 (
The board connector 115 may be soldered to the PC board 250 by any convenient or desired technique, such as, but not limited to, wave soldering or reflow soldering. After the connector 115 has been soldered to the board, the assembly 122 is then inserted into the receiving area 121 on the back side 118 of the connector 115. The assembly 122 is then held in the connector 115 by, for example, snap-in clips 132. The magnet assembly 122 may also be secured in the connector 115 by other techniques which allow the magnet assembly 122 to be inserted into the connector 115, but which prevent its easy removal from the connector 115, such as, but not limited to, tabs. The magnet assembly 122 may therefore be installed in the connector 115 after any soldering operations, so the heat of the soldering operation does not affect the magnet 130, and hand-soldering of the connector 115 is avoided. In an alternative embodiment, the magnet 130 and flux plates 125A, 125B may also be contained in a separate housing, case, or container, 131 that snaps into connector 115 or receiving area 121 after soldering. Also, as this housing 131 is not subjected to soldering temperatures, it may be made of a less heat-resistant material than the body 116 of the connector 115. In another alternative embodiment, as the flux plates 125A, 125B are not magnetized and are not adversely by wave- or reflow-soldering temperatures, they may be installed in the body 116 prior to the connector 115 being soldered to the PCB 250, and then the magnet 130 may be inserted or installed between the flux plates 125A, 125B after the wave- or reflow-soldering operation is completed.
Preferably, the strike plate 155 not magnetized. This avoids the additional cost of using another magnetized component, and also avoids implementing techniques to verify that the plate 155 will be installed, and has been installed, with the correct magnetic orientation. In another embodiment, however, the plate 155 may be magnetized, if desired, so as to provide a stronger attraction between the connectors 110 and 115, and may also serve to assist in properly orienting the connectors.
Preferably, but not necessarily, a strain relief 235 is used with respect to the cable 105 and cable connector 110. In one embodiment, the cable 105 has an outer diameter of 3.5 mm. Other diameters may be used, as desired, or to accommodate a particular installation or use.
Also, if desired, an LED status indicator 240 may be used on, for example, the cable connector 110. The indicator 240 may be connected to one or more of the contacts 220A1, 220A2, 220B1 to signify different events. For example, a green LED may be connected between power and ground contacts to indicate that power is on, and a yellow LED may be connected between a signal contact and a ground (or power) contact to indicate that a battery is charging.
The shape of the sockets 220A, 220B of the cable-end connector 110 may be closed, as shown in
The electrical contacts 120A1, 120A2, 120B1, 220A1, 220A2, 220B1 may be implemented as 2, 3, 4, 5, etc., pins (contacts), as desired for a particular installation or use. The pins are typically for ground and power, and may also provide one or more signal paths. The electrical contacts are preferably rated for 3 amps or 5 amps, but may have another rating appropriate for a particular installation or use. The electrical contacts 120A1, 120A2, 120B1 of the board connector 110 may be in-line, as shown in
The separate magnet assembly 122 allows the magnet 130 to be installed after any high-temperature soldering operations, thus eliminating the need for hand-soldering. Also, the closed magnetic circuit provides for a stronger attractive force to hold the connectors together.
It should be noted that the magnet assembly 122 may be also be configured in an open-circuit magnet configuration, if desired for some reason. This still allows the magnet assembly 122 to be installed after the board connector 115 has wave- or reflow-soldered to the PC board.
Thus, a method of using the magnetic connectors described herein would be to install the connector 115 on a PC board, wave- or reflow-solder the connector 115 to the PC board, and then insert the magnet assembly 122 into the connector 115.
Based on the foregoing, it should be appreciated that a heat resistant magnetic connector system has been disclosed herein. Although the subject matter presented herein has been described in language specific to systems, methodological acts, mechanical and physical operations and/or configurations, and manufacturing processes, it is to be understood that the invention disclosed herein is not necessarily limited to the specific features, configurations, or components described herein. Rather, the specific features, configurations and components are disclosed as example forms. Further, all of the various features, configurations, and components need not be embodied in a single item to gain the benefits of other features, configurations, and components. For example, a magnetic connector is provided that may be installed on a printed circuit board by wave-soldering or reflow-soldering, and without hand-soldering.
The subject matter described herein is provided by way of illustration for the purposes of teaching, suggesting, and describing, and not limiting. Alternatives to the illustrated embodiment are contemplated, described herein, and set forth in the claims. Various modifications and changes may be made to the subject matter described herein without following the example embodiments and applications illustrated and described, and without departing from the true spirit and scope of the present invention.
It should be appreciated that the above-described subject matter may also be implemented as an electrical apparatus, a manufacturing process, an electrical and mechanical system, or as an article of manufacture. The features, functions, and advantages that have been discussed can be achieved independently in various embodiments of the present disclosure or may be combined in yet other embodiments.
This application claims the priority of U.S. Provisional Patent Application No. 61/883,690, filed Sep. 27, 2013, and titled “Heat Resistant Magnetic Connector”, the entire disclosure and contents of which are hereby incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 61883690 | Sep 2013 | US |
