Charging problems 67 Barracuda

A month ago I was driving and some white acrid came through the firewall. Thinking I had an engine fire I pulled over to check it out - nothing. A short time later the alternator failed, which I replaced. However it is still not charging the battery. I replaced the regulator, started the car and more acrid white smoke. This time the car was stationary and the smoke clearly came from the area of the regulator. Any ideas why it's eating regulators and how to fix it?