JPH0428159B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical field to which the invention pertains) The present invention relates to a printed circuit board plugging device for inserting and removing a printed circuit board having a large number of plug terminals into and from a multi-terminal connector on the power supply side.

(Prior art) When a printed circuit board that is supplied with power through a contact terminal is inserted into or removed from a multi-terminal connector, an arc is generated between the power supply terminal contacts when current is being applied, and depending on the magnitude of the current flowing, an arc is generated between the power supply terminal contacts. As is well known, this may cause the terminal plug to burn out, which is unfavorable in terms of reliability and safety. In order to avoid this problem, conventionally, before and after inserting or removing a printed circuit board, a manual switch or relay installed on the connector on the power supply side or the printed circuit board on the load side is used to temporarily stop the energization during insertion or removal. Alternatively, a device is used that uses a mechanical switch or a non-contact switch to detect that the printed circuit board is mechanically fully inserted and then turns on the power.

However, while the former is a relatively simple and economical device, it is not easy to maintain and inspect, and problems may occur due to handling errors, such as insertion/extraction while the power is on or forgetting to turn on the switch after insertion. In addition, although the latter can avoid such erroneous operations, it requires special ingenuity for the board and connector to detect the board insertion state, and there are significant restrictions on mechanical accuracy, and reliability is generally low. The drawback is that it is difficult to improve and the equipment is expensive.

(Specific Object of the Invention) The present invention eliminates the drawbacks of the conventional device as described above.
The object of the present invention is to provide an economical printed circuit board plugging device that is free from the risk of erroneous operation, has fewer restrictions on mechanical accuracy, and is economical.

(Structure and operation of the invention) The present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a plan view showing the main parts of an embodiment of the present invention, including a plug terminal portion formed by printed wiring on a printed circuit board, and a printed circuit board that supplies power by contacting and electrically contacting the plug terminal portion. FIG. 3 is a plan view illustrating an example of a state of connection with a connector for use with the connector, and exaggerates the case where the insertion length is uneven. In the figure, 1 is a printed circuit board connector, and T ₁ , T _l , T _n ,
T _n+1 and T _o are the 1st, lth, and 1st from the bottom, respectively.
It represents the m-th, m+1-th, and top n-th connector terminals, among which T _n+1 and T _l are connected to the current supply point and the current return ground point, respectively. Further, T _n is a connector terminal adjacent to T _n+1 above and below, or on the front and back sides, and is used for detecting an insertion connection state, which will be described later.

2 is a printed circuit board, P ₁ , P _l , P _n , P _n+1 ,
P _o is a printed circuit board plug terminal corresponding to the connector terminals P ₁ , P _l , P _n , P _n+1 , and P _o , respectively.
Of these, P _l is wired to the ground line on the board.
In the present invention, in particular, the detection connector terminal
In P _n , the copper foil of the contact conductor at the tip indicated by diagonal lines in the figure has been removed by etching, etc., so that it is formed shorter than the other plug terminals and is shifted in the board removal direction. Therefore, at the time when the detection connector terminal P _n starts contacting the corresponding connector terminal T _n , at least the corresponding power supply connector terminal T _n+1 , the power receiving connector terminal P _n+1 , and The structure is such that both the grounding terminals T _l and P _l are in sufficient contact with each other.

3 is a switch circuit that electrically opens and closes the power supply line, IN is connected to the power receiving connector terminal P _n+1 which is the power input terminal, and OUT is connected to the load side circuit on the printed circuit board (not shown). )It is connected to the.
SENSE is connected to the connection terminal P _n for detecting the insertion and connection state of the printed circuit board.

2A and 2B both show simple configuration examples of the switch circuit 3 shown in FIG.
is a PNP transistor, and 32 of B is an NPN transistor. In both cases A and B, the base terminal is used to detect the electrical insertion connection state, and 33 is a current-limiting resistor connected to the base terminal, and the other end becomes the detection terminal SENSE. Further, the emitter terminals and collector terminals of the transistors 31 and 32 function as the above-mentioned IN or OUT terminals.

Next, the opening/closing operation of the power supply path when inserting and removing the printed circuit board in the embodiment of the present invention shown in FIGS. 1 and 2 will be explained using the time chart shown in FIG. 3.

Figure 3 shows the connection between the power terminals T _n+1 P _n+1 , between the ground terminals T _{l and} P l, and for detecting the insertion and connection status between the printed circuit board connector 1 and the printed circuit board 2 shown in Figure ₁ , from insertion to removal. This is a time chart showing an example of changes in the contact state and disconnection state between the terminals T _n P _n , where the horizontal axis indicates time, and the corresponding terminal names are attached to the left end of the diagram. Further, "contact" and "disconnection" at the right end of the figure represent a contact state and a disconnection state, respectively.

Now, in FIG. 1, insertion of the printed circuit board has started, and at the point in FIG. 3, that is, when the detection terminals T _n P _n start to come into contact, at least the power supply terminals T _n+1 P _n There is already sufficient contact between ₊₁ and ground terminals T _{l and} P _l . Therefore, even if the load on the printed circuit board side starts to be energized after that point, no arc will occur between the power supply terminals. At this point, switch circuit 3
Since the SENSE terminal, that is, the detection terminals P _n and T _n are electrically connected, for example, as a switch circuit, use Fig. 2A in the case of a positive voltage power supply, and Fig. 2B in the case of a negative voltage power supply. If the emitter terminals of transistors 31 and 32 are connected as IN and the collector terminal as OUT, and T _n is connected to the ground point, the power supply path of transistors 31 and 32 will be in a conductive state after that point, so arcing will not occur. energization starts without. Note that when using the switch circuit 3 shown in Figure 2B for a positive voltage power supply and Figure 2A for a negative voltage power supply, the emitter terminal and collector terminal connections should be reversed from the above case, and T _n Just connect it to the power supply point.

Next, when the printed circuit board is removed, when the detection terminals T _n and P _n are disconnected at the time shown in FIG. 3, the switch circuit 3 is opened and the power supply path is disconnected. At this time, between the power terminal T _n+1 and P _n+1 , the ground terminal
There is still contact between Tl _{and Pl} , and they separate after a while, so no arc occurs between the power supply terminals.

As is clear from the explanation of Fig. 3 above, during the closing operation (interval) of the switch circuit 3, the possibility of the power supply terminal contacting and disconnecting is eliminated, so it is possible to prevent arcing. .

Note that if the time difference between the contact between the detection connector terminals T _n P _n and the contact between the power terminals T _n+1 P _n+1 or T _l P _l is more than a few milliseconds, the semiconductor switch circuit is If so, the response time is generally within several microseconds, so the desired safe opening/closing of the power supply path can be achieved. Therefore, the detection connector terminal P _n is placed above, below, or adjacent to the front and back of the power supply terminal P _n+1 so that the tip of its contact conductor is shifted in the removal direction from the other connector terminals. , if the length of the deviation is selected, at least the time difference between the contact operation between the power supply terminals T _n+1 P _n+1 and the contact between the detection terminals T _n P _n will be It is clear that the above conditions can be easily guaranteed regardless of the type of connector.
Furthermore, if the ground terminal P _l is also placed adjacent to P _n , perfect conditions can be obtained.

In addition, the switch circuit 3 can be mounted not only on the printed circuit board as described above but also on the connector side, but in this case, the detection connector terminal P _n is connected to P _n+1 on the board
Alternatively, if it is connected to P _l , exactly the same effect as above can be obtained.

The above explanation is based on the case where the conductor part of the plug terminal P _n for detecting the printed circuit board insertion/connection state is provided on the printed circuit board by shifting it in the direction of board removal.
The conductor portion of the detection connector terminal T _n may be provided to be shifted in the board insertion direction, or a short connector terminal equivalent to one without copper foil may be used.

(Effects of the Invention) As described in detail above, according to the present invention, the conventional drawbacks of printed circuit board plugging devices can be wiped out. There are no restrictions on terminal assignment other than the relative arrangement with the power supply terminals, and there are fewer restrictions on the mechanical precision of the printed circuit board. Moreover, the switch circuit that opens and closes the power supply path of the power supply circuit is on the printed circuit board side.
It can be used on either side of the connector, and it can be easily implemented, offering an extremely high degree of freedom in design, and is economical and highly effective.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the main parts of an embodiment of the present invention, FIG. 2 is a diagram showing an example of the configuration of the switch circuit shown in FIG. 1,
FIG. 3 is a time chart showing the contact and disconnection states of the connector between the printed circuit board and the connector. 1...Connector, 2...Printed circuit board, 3...
Switch circuit, 31...PNP transistor, 3
2...NPN transistor, 33...Resistor, P ₁ ,
P _l , P _n+1 , P _o ...Plug terminal of printed circuit board, T ₁ ,
T _l , T _n+1 , T _o ... Connector terminal, P _n ... Detection connector terminal provided on the board, T _n ... Detection connector terminal corresponding to P _n .

Claims (1)

[Scope of Claims] 1. A power supply side connector having a large number of connector terminals including a power feeding connector terminal, and a large number of connector terminals including a power receiving contact terminal arranged corresponding to the power feeding connector terminal. a printed circuit board that is inserted into and removed from the connector; and a printed circuit board that is provided adjacent to each of the power supply connector terminal and the power reception connector terminal, and the length of one of the contact conductors is longer than that of the other connector terminal. or a detection connector terminal and a detection connector terminal arranged to correspond to each other and shorter than the length of the contact conductor of the other connector terminal, and a power supply circuit or power receiving connector connected to the power supply connector terminal. It is inserted into either one of the power supply circuits connected to the terminal, and the power supply path of the power supply circuit is connected/disconnected by detecting electrical contact/disconnection between the detection connector terminal and the detection plug terminal. and an electronic switch circuit that performs an operation as described above, and when the printed circuit board is inserted, the power feeding circuit starts supplying power after the power receiving connection terminal of the printed circuit board contacts the power feeding connector terminal of the connector. The printed circuit board connector terminal is configured such that when the printed circuit board is removed, the power reception connector terminal is detached from the power supply connector terminal after the power supply from the power supply circuit is cut off.