WIRING QUESTION

Hello
I am planning to do my 737 mip and ovh panel but i have two questions , firstly :
I have read the Opencockpits master card manual and i know that on every input group on the master card there are 9 pins + 1 gnd so my question is how am i going to connect 1 gnd wire for 9 other wires . should i connect them all together so that they will then share one gnd pin . And my other question is when wiring all the knobs , switches and annunciators is this wire suitable for connecting them to the master card Cable 0,5 (para cablear la cabina )
thanks

Yes to both questions. When planning your wiring to the switches, you need to allocate the rotary switches first so that you can make sure that all the needed pins are within one "group" of 9 inputs. Spare inputs within the group of 9 then be filled up from other switches. The common ground wire should be daisy chained between the switches that are within the group before terminating at the mastercard ground pin.

David

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Originally Posted by fordgt40

Yes to both questions. When planning your wiring to the switches, you need to allocate the rotary switches first so that you can make sure that all the needed pins are within one "group" of 9 inputs. Spare inputs within the group of 9 then be filled up from other switches. The common ground wire should be daisy chained between the switches that are within the group before terminating at the mastercard ground pin.

David

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I have searched for the term daisy chain but it only gives me a example on usb or headphone cables can you give me an actual example because it seems that i still didnt get the concept
Thanks

Ok

Lets suppose that you have a 4 position rotary, 2 x 2 position toggle switches and a push button.

Then you would run the ground wire from the centre of the rotary switch (that is generally the common pin) to the centre pin of the first 2 position toggle switch. Then on to the centre pin of the next toggle switch and then on to the "push button" switch and then finally to the mastercard group ground terminal connector. That way each switch has a linked common wire which terminates at the mastercard. All the other used pins on these switches are wired independently to the master card inputs within the group served by the common ground

David

Quote:

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Originally Posted by fordgt40

Ok

Lets suppose that you have a 4 position rotary, 2 x 2 position toggle switches and a push button.

Then you would run the ground wire from the centre of the rotary switch (that is generally the common pin) to the centre pin of the first 2 position toggle switch. Then on to the centre pin of the next toggle switch and then on to the "push button" switch and then finally to the mastercard group ground switch. That way each switch has a linked common wire which terminates at the mastercard. All the other used pins on the switches are wired independently to the master card inputs attached to the common group ground

David

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You have saved me hours of researching THANK YOU

Glad to help. Also, please note that I have edited my earlier post to remove a typo and hopefully clarify the meaning :D

Quote:

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Originally Posted by fordgt40

Glad to help. Also, please note that I have edited my earlier post to remove a typo and hopefully clarify the meaning :D

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Well i have another question :roll: . On my first post i inserted a link for cockpit wiring from OC. If i order it must i tell them that i need for example a red wire or it doesnt matter which color i use also if i order the wires can i use ANY wire as my gnd wire or must it be a specific kind
THANKS

The electronics do not know or indeed care what colour wire you use :D

Logic suggests you use a colour such as black for grounds, and use the same wire type for all electronic signals ie inputs/outputs. The wire in the link is solid core and keeps its shape when bent, also cannot be bent too many times. If you want flexible wire then just choose a multistrand type of the same thickness or slightly thicker. Remember that power supplies eg 5 volt may need slightly thicker wire to avoid voltage drop on long runs

Quote:

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Originally Posted by fordgt40

The electronics do not know or indeed care what colour wire you use :D

Logic suggests you use a colour such as black for grounds, and use the same wire type for all electronic signals ie inputs/outputs. The wire in the link is solid core and keeps its shape when bent, also cannot be bent too many times. If you want flexible wire then just choose a multistrand type of the same thickness or slightly thicker. Remember that power supplies eg 5 volt may need slightly thicker wire to avoid voltage drop on long runs

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is this good ? https://www.modmypi.com/multi-strand-wire-blue

It is the same thickness and is multistrand - so yes

Quote:

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Originally Posted by fordgt40

It is the same thickness and is multistrand - so yes

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Thanks for the help . But i have ONLY 1 more question left (please bear with me) lol. I know that for every input a wire or more goes to the interface card and One wire is connected to 9 inputs which is ground .so my question is how will i solder the same wire to connect 9 ground pins on the switches to only one ground pin on the master card
thanks

You connect the ground pin of the first switch to the ground pin of the second switch to the ground pin of the third switch etc.
Then you connect the 9th ground pin also to the OC ground, so only one connection for nine switches.
Hope this helps.

Quote:

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Originally Posted by tiburon

You connect the ground pin of the first switch to the ground pin of the second switch to the ground pin of the third switch etc.
Then you connect the 9th ground pin also to the OC ground, so only one connection for nine switches.
Hope this helps.

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Yes i know that but i mean that if im using only one wire for the ground connection how can i solder it multiple times on multiple pins . because a wire only has two sides
Thanks

On all the intermediary connections you attach (by bending around or passing through the terminal hole) the incoming wire and outgoing wire at the switch terminal. Then you solder this connection to make it permanent.