Protel GND isolation

[Astable Schmitt]

Is there any way to simulate the coupling of 2 circuits with isolation?
(opto-coupler, transformer e.t.c). I am trying to simulate a telephone
circuit and don't want my circuit to have the same GND reference as the
telephone network.

I have tried renaming a second ground net to GND2 but it won't simulate.

Any help would be greatly appreciated.

P.S I am using Protel 99SE

 

[Alexander Peter]

"Astable Schmitt" <sick@of.spam> schrieb im Newsbeitrag
news:Xns93E08396DC75Esickofspam@202.89.128.20

Is there any way to simulate the coupling of 2 circuits with
isolation? (opto-coupler, transformer e.t.c). I am trying to simulate
a telephone circuit and don't want my circuit to have the same GND
reference as the telephone network.

I have tried renaming a second ground net to GND2 but it won't
simulate.

Any help would be greatly appreciated.

P.S I am using Protel 99SE

What about coupling GND and GND2 with a very high impedance, e.g. 10Meg ||
1pF?

HTH

Alexander