| 摘要 |
A method and apparatus for providing an ac signal to load terminals, where the signal has a reduced open circuit voltage is disclosed. The apparatus includes an ac current source connected to the load terminals and an open circuit sensor. A control circuit is connected to the source of ac current and to the open circuit sensor, and when the sensor senses an open circuit the control circuit causes the current source to provide a dc signal. The dc signal is created by allowing the current source to provide a signal of only one polarity. The polarity may be either electrode positive or electrode negative. The current source may be either a phase controlled current source or an inverter. The method includes the steps of detecting the presence of an open circuit at the load terminals and causing the ac power source to provide a half wave signal of only one polarity in response to the detection of an open circuit.
|
