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From: dbird@eskimo.com (Dan Bird)
Subject: Re: Optocouple a RS-232 device ?
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Date: Wed, 22 Mar 1995 23:29:40 GMT
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Xref: glinda.oz.cs.cmu.edu sci.electronics:124844 comp.robotics:19159

Christer Johansson (cj@aristotle.algonet.se) wrote:

[clip]
: And on the receiver side it's fine with TTL logics.

:      RS-232 RS-232   Opto-      TTL
:      Port   Levels   isolation  Levels

:       - ---+         +---------+
:            |-TxD-----|         |-TxD-->
:            |-RxD-----|    ?    |-RxD-->
:            |-DCD-----|         |-DCD-->
:            |-RTS-----|         |-RTS-->
:       - ---+         +---------+

[clip]
Digikey (1-800-digi-key) sells many opto isolators and a nifty little 
chip that will drive RS232 from TTL -- itz got a built in charge pump.  
I've not used it yet but it sounds like it could be just the number you 
need.  Digikey (who I am Not affiliated with) is quit tolerant of small 
orders -- I've been buying parts from them since I was 13.

Good luck!
-- 
`;^} D'Bird (dbird@eskimo.com)
'
