--- In [email protected], "w7qjq" <[EMAIL PROTECTED]> wrote: > > --- In [email protected], "olanie" <Marc.olanie@> wrote: > > > > hi > > > > Question to the audio gurus : > > > > Is it possible to use AOI (analog optical isolators) between the > > softrock and the audio card, instead of reather expensive Triad > > transformers ? I found this application note, but have no idea > > concerning the effective linearity of such components. I also have no > > info concerning the bandwith we can reach with such AOI's (in a > > perfect world, 192 KHz of flat response will be ok :-) ) > > > > Marc f6itu > > > > I have uploaded to the Files area in the *W7QJQ folder > an image of an inexpensive audio groundloop fix using > Zicon transformers from Mouser. > > 73, Sid W7QJQ > Oklahoma > > member DNA, National Dyslexic Assoc > I've looked at these AOI's, they're basically an LED and an LDR (Light Dependant Resistor) potted together in a cube. Response time looks poor for this application, and dynamic range is limited as well. They're expensive if memory serves.
I agree with Sid, scrounge a couple of old isolation transformers from a couple of old dial-up modem cards or old phones. What I need is some opto-isolators that will work between the PC parallel port and 3.3V CMOS logic levels directly, and support through-put high enough to carry 400kHz I2C to/from the Si570. 73's Dave
