Thetelegrapher’s equations(or justtelegraph equations) are a pair of coupled,that describe theandon an electricalwithand. The equations come fromwho developed thestarting with an August 1876 paper,On the Extra Current.:6667The model demonstrates that thecan be reflected on the wire, and that wave patterns can form along the line.
The theory applies to transmission lines of all frequencies includingand. Originally developed to describewires, the theory can also be applied to, audio frequency (such as), low frequency (such as power lines), and pulses of. It can also be used to electrically modelas truncated single-conductor transmission lines