Wiring KDR-510

Why does the KDR-510 datalink receiver use two input wires for power and
two for ground? The schematic looks like this

KDR-510
3A
10-30 VDC---()-------------Power positive 1
\------------Power positive 2


Ground-------------|-------Power ground 1
|-------Power ground 2


Is the power positive 2 and power ground 2 wires just for redundancy?
I've never seen any avionics that use two wires both for power and ground.
Do both 1 and 2 need to be hooked up or just power and ground 1?

Chad Lemmen writes:

Why does the KDR-510 datalink receiver use two input wires for power and
two for ground? The schematic looks like this

KDR-510
3A
10-30 VDC---()-------------Power positive 1
\------------Power positive 2


Ground-------------|-------Power ground 1
|-------Power ground 2


Is the power positive 2 and power ground 2 wires just for redundancy?
I've never seen any avionics that use two wires both for power and ground.
Do both 1 and 2 need to be hooked up or just power and ground 1?

I've seen this used in computer wiring where more power is needed on
"one" lead than on the others. This lets them use a smaller connector
(with one or two additional pins). Power and ground are the things
that's likely to be the issue for with avionics, so maybe that's the
purpose?
--
David Dyer-Bennet, , www.dd-b.net/dd-b/
RKBA: noguns-nomoney.com www.dd-b.net/carry/
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Dragaera mailing lists: dragaera.info/

Chad Lemmen wrote:

: Why does the KDR-510 datalink receiver use two input wires for power and
: two for ground? The schematic looks like this
snip
: Is the power positive 2 and power ground 2 wires just for redundancy?
: I've never seen any avionics that use two wires both for power and ground.
: Do both 1 and 2 need to be hooked up or just power and ground 1?

Chad, the King equip I have (KX-155, KN-62) also have 2 pins each for power
and ground. These pins are connected together internally in both units.
They are hooked up using 22ga wire, so I suspect that some limit on current
in a 22ga wire is exceeded with a single wire. I would hook up both pins.
--
Aaron Coolidge (N9376J)

I use a rule o'thumb of 5 amps for 22 awg and 7 amps for 20 awg (tefzel or
equiv.)
The double power lead method bothers me because if one of the wires broke,
the equipment might then try to pull a full load thru a single (undersized)
wire...unless there is some special circuitry inside the box that prevents
that. Same thing for grounds...


"Aaron Coolidge" wrote in message
...
Chad Lemmen wrote:

: Why does the KDR-510 datalink receiver use two input wires for power and
: two for ground? The schematic looks like this
snip
: Is the power positive 2 and power ground 2 wires just for redundancy?
: I've never seen any avionics that use two wires both for power and
ground.
: Do both 1 and 2 need to be hooked up or just power and ground 1?

Chad, the King equip I have (KX-155, KN-62) also have 2 pins each for
power
and ground. These pins are connected together internally in both units.
They are hooked up using 22ga wire, so I suspect that some limit on
current
in a 22ga wire is exceeded with a single wire. I would hook up both pins.
--
Aaron Coolidge (N9376J)