[GreenKeys] RS-232 to 60mA current loop conversion for Model 15 TTY?

[Jon Schlegel]

Very nice part.  I see the 412 series is good for 400 volts.

Thank you,
Jon


At 10:54 AM 1/26/2009 -0600, Jim Haynes wrote:
>Take at look at the Fairchild HSR312, an opto-isolated FET switch,
>takes 2ma to turn it on, good for 250 volts and 190 ma.  Of course you
>have to use some kind of snubber to limit the inductive kick, such as
>an R-C or a Zener diode or a MOV device.  Costs $1.72 at Mouser.
>Add a 1N5956 200V Zener diode for 24 cents.
>
>I haven't used any of these yet, but sure looks like a good tool
>for the purpose.
>
>
>
>
>jhhaynes at earthlink dot net
>
>
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