[GreenKeys] HRS312 TTY Interface

[David Ross]

The HSR312 is a simple & convenient device to use, but it introduces 
significant distortion.  The HSR312's turn-on time is specified at 3.0 
millisecond max and it's turn-off time is specified at .5 millisecond max.

This is probably negligible if one uses the HSR312 between a PC and a 
teleprinter, but if you are dealing with off-the-air signals then the 
distortion may become objectionable.

Dave Ross    N7EPI



Duncan M. Brown wrote:
> Then last month someone mentioned the HRS312 MOSFET optocoupler and that
> looked like the heart of a very simple interface.  Jon Schlegel and I have
> been playing with the HRS312 and  it seemed like the circuit was so simple
> that it could be placed inside the 9-pin D-connector's housing.  I found I
> had some AMP 745854-3 housings. There is room for a 5/8" x 3/4" board,
> which is plenty big enough (point-to-point wiring).
>