ECN Forum Forums General Topics of the Trade Voice - Data - Video Discussion How could this be done legally???

"If you are worried about crosses, 12VDC would not even begin to bother the phone if applied across the T/R which normally works with 48VDC."

Not to mention that the ringer signal is usually 85-90 Volts AC. So all the phone equipment is rated well in excess of 12VDC.