| 摘要 |
A fault protection circuit for a respiratory conduit heater element (3) in a respiratory humidification system is disclosed. The circuit includes a spark detector as well as overcurrent detector. Several variations are included for the spark detector including a two winding transformer (2,5), a centre tapped two winding transformer (2,5,18), and a high pass filtered (16a,16b) inductor (15). A semiconductor switching configuration (42 & 43) is also disclosed. Once the protection circuit detects a change in current over a certain level, or the average level raises above a threshold, then the current in the heater (3) is interrupted for a preset period. <IMAGE> |
