Hi,
          When it comes to electrical devices and safety concerns, you'd
     best make an enquiry to your local electrical inspection office. Here
     in Ontario Canada, we'd have to have a device of this nature conform
     to Ontario Electrical code, and then have the device either CSA
     approved, or have an Ontario Hydro Special Inspection performed, and
     modify the device to meet approval, which means that it must comply
     with the Ontario Electrical code.  Here, there is a class for low
     current signalling transformers of 30v or less, which has its own
     category. I dare say that your device would be considered a high
     voltage device (750 volts or less by standards here) as far as the
     electrical authority was concerned.

     Cheers,
     Joe Sangemino
     Ottawa Regional Cancer Centre
     jsangemino@octrf.on.ca