| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a signal transmission circuit for an air conditioner capable of preventing damage to communication circuits caused by the application of voltages higher than those used during communication. <P>SOLUTION: The signal transmission circuit 100 includes interfaces 27, 47, the communication circuits 28, 48 and power supply parts 29, 49. The interfaces 27, 47 include wiring connection terminals 27a, 47a to each of which communication wiring 9 is connected. The communication circuits 28, 48 perform the communication of an indoor unit 2 and an outdoor unit 4. The power supply parts 29, 49 generate first voltages for communication by the communication circuits 28, 48 via the communication wiring 9 and supply the first voltages to the communication circuits 28, 48. The communication circuits 28, 48 include overvoltage protection parts 28a, 48a for protecting damage to the communication circuits 28, 48 caused by second voltages when second voltage wiring 11 to each of which the second voltage higher than the first voltage is applied are connected to the wiring connection terminals 27a, 47a of the interfaces 27, 47. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
