Jim Wilkins wrote:

On Sep 27, 8:49 am, Bob Engelhardt wrote:
The fastest way to match-up ends of wires in a cable is a binary search.
Where fastest means the least number of tests. The number of tests
required is the number of bits needed to represent the number of wires.
E.g. 64 wires would require 6 tests. This is especially efficient
where each test means traveling some distance between the ends of the
wires. I used it where I had a bunch of unmarked wires coming into a
fuse panel, the other ends of which went all over the house. Each test
involved traveling the house, testing each end.

A binary search involves dividing the wires into 2 groups for each test,
then redividing them for the next test. When you're done, each wire has
been in a unique collection of groups. For example, say you have 8
wires, arbitrarily numbered 1 through 8. For the 1st test, wires 1 - 4
are tied together (5-8 are loose). In the next test 1-2,5-6 are (all)
tied & the 3rd test 1,3,5,7. For each test, the tied-together wires are
rung to each of the loose wires on the other end. So, if a other-end
wire rung to groups 1 & 3, it would be wire 3 (1-4, not 1-2, 1 or 3).

I could be more explicit, but you get the idea. If you number and group
the wires right, the ring-ing groups are the binary number of the wire.

HTH,
Bob

BTW - it's "ringing out" cables, from the use a buzzer/bell to test
continuity.

That's a very efficient method when you have a way to jumper the wires
together in groups, but it doesn't work well for connectors if you
don't have spare mating pins.

I do the binary search a little differently to keep it simple. Connect
1+2+3+4 and check. If open I'd connect 5+6 and check. If open I'd try
7, then 8 just to confirm it. The number of tests is the same but
there's less handling damage to the wire ends.

I traced out my fuse box with a vacuum cleaner that makes a low rumble
which travels through the floors and frame of the house.


We used to use a cheap radio for that.


--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.