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I have two cables each with 10 pins, that connects between two PCBs. I would like to be able to connect and disconnect them from each other. Something like this link to 10 pole mechanical switch, however instead of pressing manually I want to automate it. I have also looked into relay boards but have not found any that have several outputs and it would be too bulky having 20 relays.

enter image description here

To clarify I need to connect/disconnect 20 pins with one signal, it is not necessary to be able to control them individually. The pins are used for SPI communication, however I was hoping to find something like this 4 pole relay but with 10 poles instead. We use this for testing purposes and not in the final design, as of now we manually disconnect the cable during each test. So I am looking for some already created device that can act as the "dis-connector".

Heneer
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    You need to define precisely what you want to achieve functionally. At the moment your question is unclear despite you probably thinking it is clear. Why not draw a little picture and include an imaginery 10 pole switch if necessary - show the inputs and where they might route to as outputs. – Andy aka May 03 '18 at 07:34
  • A solid state relay such as a CPC1017N? There are also dual and quad version of the same thing. – Steve G May 03 '18 at 08:21
  • We need a lot more information about your data signals. e.g. Type, voltage, direction, frequency, anything you can give us. Switching a 9600 baud UART is tad different from a PCIe. – Oldfart May 03 '18 at 09:31
  • You say you want to switch multiple signals, but your schematic shows the signals on each PCB connected together. Not only does the schematic contradict the description, but paralleling mechanical switches to get more current is a bad idea. – Olin Lathrop May 03 '18 at 12:40
  • Everything seems so clear in my head, the drawing was indeed confusing. No paralleling mechanical switches, my bad! – Heneer May 03 '18 at 13:41

3 Answers3

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The solution to your problem depends on the signals being switched and since they are data signals - on data direction. If you have many outputs and one input - use multiplexer (MUX): example of MUX. If you have one output and many inputs - use demultiplexer (DEMUX). If the data direction is not defined, use MUX/DEMUX: example of MUX/DEMUX. These devices can be daisy-chained if the channel count is too low.

Stu Zender
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  • OP doesn't appear to want to multiplex signals - he/she wants to switch a set of 1-to-1 signals simultaneously. – Ryan Griggs May 03 '18 at 14:45
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You can just connect the coils of 5 DPDT relays in parallel and control it with one signal. Eg. Omron G6K. 12V coil, 5 in parallel only draws 45mA. 4.5V coil 116mA. That would do the same thing as the switch (select one of two to be connected x 10).

But if your signals are digital SPI signals you might want to use digital tristate buffers, multiplexers or something like that- it seems like your problem is poorly defined.

Spehro Pefhany
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Why not use a bidirectional buffer/transceiver chip? For example, the 74LCX16245 is a 16-bit 5v bidirectional buffer with an Enable line. You can use the enable line to "turn on" and "turn off" the inputs or outputs. Two of these chips would provide more than enough IO pins for your need. If you have both inputs and outputs, you can use one chip for input pins and the other for outputs, then they both can be enabled/disabled with a single pin.

IMPORTANT: the above chip requires you to set the data direction manually using the direction pin. While this will work if you already know the direction of data flow, you may also want to consider an auto-sensing bidirectional bus transceiver such as the TI TXB0104 or similar device. The only problem is that these are designed to translate 3.3V to 5V signals. One side can only accept up to 3.3V inputs, so you may be able to use a simple voltage divider for that. However, it won't boost the 3.3v output back up to 5V for the other direction.

I hope this at least points you in the right direction.

Ryan Griggs
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