Editing Ringer equivalence number (section)

==Definition==
The ringer equivalence of 1 represents the loading effect of a single traditional telephone ringing [[electrical network|circuit]], such as that within the Western Electric [[model 500 telephone]]. The ringer equivalence of modern telephone equipment may be significantly lower than 1. For example, externally powered electronic ringing telephones may have a value as low as 0.1, while modern line-powered telephones, in which the ringer is powered from the telephone line, typically have a REN of approximately 0.8.

In the United States, the FCC Part 68 specification defined REN 1 as equivalent to a 6930 [[Ohm (unit)|Ω]] [[resistor]] [[Series and parallel circuits|in series]] with an {{gaps|8|μF}} ([[Farad|microfarad]]) [[capacitor]].  The modern ANSI/TIA-968-B specification (August 2009) defines it as an [[electrical impedance|impedance]] of {{gaps|7000|Ω}} at {{gaps|20|Hz}} (type A ringer), or {{gaps|8000|Ω}} from {{gaps|15|Hz}} to {{gaps|68|Hz}} (type B ringer).