# Series Parallel combinations

Discussion in 'Electronic Design' started by Abstract Dissonance, Jan 10, 2006.

1. ### Abstract DissonanceGuest

For my project I wanted to be able to programmatically decide how to "wire"
certain components in series and/or parallel combinations in and out of
phase. After doing some calculations this seems impossible if I want to be
able to get all calculations.

For example, 1 component could be wired in or out of phase and one could
accomplish this(I think this is the minimum number of switches needed too)
as

*-----------------*----- Out
3/| 4/|
---- Component ----
1/| 2/|
In---*-----------------*

where the /| represent switches. I.e., if I wanted the component in phase I
could just open switches 2 and 3 with 1 and 4 close and out of phase would
result in the opposite. With an appropriate "Device" one could control this
with just 1 line. The device would have 4 internal switches but 2 pair would
be alternately configured and switch together(like a spdt with alternating
switches).

Now if I had two components I would be able to configure them in 8 total
ways with any series and parallel in and out of phase combination...

The problem is that the number of switches required seems to grow
"exponentially"(well, might as well since it seems to get large pretty quick
and I was planning on using reed relays).

one can also make a "series-parallel device" that will have 5 inputs and 1
output that can configure two components in series or parallel. I was
thinking that I could then use the phase and seriles-parallel devices to
build up for more combinations but it just seems that it gets way out of
hand really quickly.

Is there any hope of doing this project(without limiting the number of
combinations)? I was thinking that one could use a matrix of switches to
"route" the component's inputs into different configurations and one should
be able to get all the combinations but I'm not sure if this is possible...
and with just 6 components(12 leads) one has to have a 12x12 matrix which, I
think, would have to have atleast 4(maybe less depending on how the switch
works) switches per junction.

I'm not sure if this is doable with FPGA or not since I don't know much
about them yet... I really was trying to stick with relays but it seems that
it isn't going to be doable that way. I have a "prototype" that uses dip
switches to do the switching but I can only do about 15 combinations or
so(maybe a little more). I think the total number of combinations that one
gets follows the progression 2, 8, 144, 91392, 187499658240, ... . I could
be wrong though.

Anyone have a clue what I'm talking about?

Thanks,