[GreenKeys] GreenKeys Digest, Vol 102, Issue 64

[John Nagle]

On 7/23/2012 6:00 PM, greenkeys-request at mailman.qth.net wrote:
> Message: 2
> Date: Mon, 23 Jul 2012 19:36:25 -0500
> From: "Jack"<wa2hwj at att.net>
> Subject: [GreenKeys] Schematic
> To:<greenkeys at mailman.qth.net>
> Message-ID: <009001cd6934$5b823c10$1286b430$@net>
> Content-Type: text/plain; charset="us-ascii"
>
> One correction on the schematic I sent out yesterday (fixed it
> today): the opto-isolator is a H11D1, not HD11D1.

    An H11D1 seems undersized for a 60mA current loop.  Its
absolute maximum rating is 60mA, but normal current transfer
ratings for the device are 15 to 20mA, from figs 3 and 4
of the data sheet.

    I used an HSR312L (now obsolete), and Steve Garrison used
a G3VM-401B (pin-compatible, and better).  The G3VM-401B
is good for 120mA as a recommended operating condition.
Those are slower devices than an H11D1, but for any of
the 60mA machines, a 1ms delay is tolerable.

				John Nagle