Please help - new to electronics - 10 inputs from 2 boxes to be switched to third box with input selection indication.

[chrisnewkid]

Hello,

May I ask for some help to implement the attached requirement into a circuit?

I have box A and Box B - both putting out signals (analog) on 10 wires - I have box C to which these should go based on the input selection. I would like to show with 2 LEDs which input is selected. The switch should also have a neutral position where there will not be any connection to BOX A or Box B The voltages from input ranges are maximum upto 12v.

I am new to electronics and I would appreciate some help and guidance to implement this project.

 

[rjenkinsgb]

The simplest approach is an eleven pole, three way switch.

You can make one using three of these wafers:

457844/1/MA | NSF Rotary Switch Wafer 3-Position | RS

uk.rs-online.com

On a suitable body mechanism:

MU457848FPA(MA) | Rotary Switch Shaft Assembly for use with MU-MA Series | RS

uk.rs-online.com

That gives you a switch with twelve separate three-way sections; use ten for the signal contacts and another to switch the LEDs.

Each switch section has a common (the output at the right in your diagram), the contact that always connects to the centre disc in the wafer, and one contact for each switch position, connected by the tab at the edge of the disc as the switch is turned.

Use the first and third position contacts for the A and B inputs. The centre (position 2) has everything disconnected.

Another switch section would have eg. a 9V battery + connected to the common, and positions 1 and 3 to each to a 470 Ohm resistor and a LED for the indicators. The negative/cathode side of the LEDs goes back to the battery negative.

Or use a four cell AA battery holder and 220 ohm resistors, as you prefer.

 

[chrisnewkid]

Thank you very much for your kind reply. The wafer switch - never seen it before - I really appreciate you pointing me there. I learned something new! - Thank you so much.

is there a way to achieve this via relay?

 

[KeepItSimpleStupid]

"signals" is a vague term. Voltage., current, frequency. directional, bi-directional, logic, audio to name a few parameters.

 

[chrisnewkid]

"signals" is a vague term. Voltage., current, frequency. directional, bi-directional, logic, audio to name a few parameters.

it includes all of that. Sorry for missing it.

 

[rjenkinsgb]

The "off" position complicates things.

Without that, you could use just three, four-pole changeover relays to give twelve changeover contacts - but it is then always connecting either A or B through.

To allow for an "off" position, you would need three, four-pole relays for each set of signals, so six altogether.

You would also use one extra normally-closed on each relay in series with the coil of the others, making it impossible for both to be in at the same time.

That then needs a simple switch or some pushbuttons to select A / B / Off.

 

[chrisnewkid]

Thank you - so that complicates and also adds up cost. I think your first solution would be a cheaper one in terms of $ damage. Thank you Sir.

 

[rjenkinsgb]

The relay version would also need permanent power to operate the relays, taking a lot more current than just indicator LEDs.

Having a quick look on ebay, if you used six, two pole relays for each half, you could do the whole thing for not much more than £10 - not counting the battery or power supply.
eg.
**broken link removed**

However, the rotary switch has the advantage it will work even if the battery fails.