Tip and Ring are telephony slang for the two wires which make up the electrical circuit used for telephone wiring. Tip is the nickname for the electrically positive wire and Ring is the nickname for the electrically negative wire. Tip is the ground side, which is positively charged, and Ring is the battery side, which is negatively charged, of a telephone circuit. The tip is synchronized with the office of the telephone company. Ring carries -48 volts of DC voltage when in an idle or on-hook condition. The grouping of tip and ring creates a regular telephone line circuit. To make a telephone ring on an inbound call, around 90 volts of 20 Hz AC current is overlaid above the DC voltage formerly available on the idle telephone line.

 

The words Tip and Ring derived from the telephone operators’ phone plug, when operators used to manage and control user phone calls.