[GreenKeys] A reliable current-loop-to-RS232 converter

[John Nagle]

> Date: Tue, 6 Oct 2015 18:16:53 -0500
> From: Jeffrey D Angus<jdangus at att.net>
> To:"greenkeys at mailman.qth.net"  <greenkeys at mailman.qth.net>
> Cc: Gabriel Egan<mail at gabrielegan.com>
> Subject: Re: A reliable current-loop-to-RS232 converter
>
> Some time back, Gabriel was looking for an RS-232 to TTY loop converter.
> I shot my mouth off and said, "If you can't find one that works, I'll make
> one for you."
>
> Well, here it is.
> RS-232 to TTL level converter, then a pair of opto-couplers to sense and
> key the TTY loop, and a built in power supply for the loop itself. With
> selectable 20 or 60 mA operation.
>
> It's been a fun project.
>
> Jeff

    That's very similar to mine, built in 2009:

  	http://www.aetherltd.com/aesthetic.html

It's just what you'd expect - a 120VDC open frame supply,
a board with opto-isolators, solid state relay for
motor cotnrol, and a USB to serial interface.  The two
indicator lamps on the front are power on (white) and
motor on (red).  The meter is loop current.

It's somewhat overdesigned.  I built two of these, and they've
now been to seven steampunk conventions.

    Many of you have seen the video before, but here's
the link:

    https://vimeo.com/124065314

				John Nagle