Re: [Xylo-SDR] RFC - Powers

[Philip Covington <p.covington@gmail.com>]

On 1/19/06, John Kolb <jlkolb@jlkolb.cts.com> wrote:
>
> If we are going to use a 4 pin connector with gnd, +5, +/-12V, lets use
> something different than the 4 pin standard on PC power supplies to
> prevent confusion. Maybe a 5 or 6 pin with 2 or 3 grounds.
>
> John  KK6IL

John,

The 4 pin connector on a PC power supply is:

1 - +12V
2 - GND
3 - GND
4 - +5V

If we use the following pin out on our 4 pin connector:

1 - +12V
2 - -12V
3 - GND
4 - +5V

then if someone plugged the 4 pin receptacle from the PC power supply
into the motherboard power connector, they would be supplying ground
(or 0 Volts) to the -12V input line which should cause no smoke.  As a
matter of fact, if your project does not require the -12V then it
would allow you to plug in the PC power supply without having to wire
up a 4 pin receptacle to get the -12V.

I like the 4 pin molex connector because it is cheap, abundant, and
can be scrounged from many sources...

73 de Phil N8VB