COMMUNICATION DEVICE, WELDING POWER SUPPLY, WIRE FEED DEVICE AND WELDING SYSTEM

PROBLEM TO BE SOLVED: To provide a communication device capable of suppressing the attenuation of a part of a signal, even when a frequency band used in a transmission signal is close to a frequency band used in a reception signal.SOLUTION: A communication unit 13 (23) includes: a transmitter unit 51 for transmitting a communication signal to a transmission line; a receiver unit 53 for receiving a communication signal from the transmission line; a transmission filter 52 disposed between the transmitter unit 51 and the transmission line, and including a transmission BPF 52a to pass the communication signal transmitted from the transmitter unit 51; and a reception filter 54 disposed between the receiver unit 53 and the transmission line, and including a reception BPF 54a to pass the communication signal received by the receiver unit 53. A reception BEF 52b having a common center frequency to the reception BPF 54a is provided between the transmission BPF 52a and the transmission line, and a transmission BEF 54b having a common center frequency to the transmission BPF 52a is provided between the reception BPF 54a and the transmission line. 【課題】送信信号が利用する周波数帯域と受信信号が利用する周波数帯域とが近い場合でも、信号の一部が減衰してしまうことを抑制することができる通信装置を提供する。【解決手段】通信信号を伝送路に送信する送信部５１と、伝送路から通信信号を受信する受信部５３と、送信部５１と伝送路との間に配置され、送信部５１が送信する通信信号を通過させる送信ＢＰＦ５２ａを備える送信用フィルタ５２と、受信部５３と伝送路との間に配置され、受信部５３が受信する通信信号を通過させる受信ＢＰＦ５４ａを備える受信用フィルタ５４とを備える通信部１３（２３）において、送信ＢＰＦ５２ａと伝送路との間に、受信ＢＰＦ５４ａと中心周波数を共通にする受信ＢＥＦ５２ｂを備え、受信ＢＰＦ５４ａと伝送路との間に、送信ＢＰＦ５２ａと中心周波数を共通にする送信ＢＥＦ５４ｂを備えるようにした。【選択図】図２