摘要 |
<p>An electrical machining apparatus incorporating features against malfunctioning or delay to reach a normal operation upon recovery from a power failure or shut-off in the input source is provided. The apparatus having a plurality of electrical output devices, e.g. a machining power supply, a fluid pumping system and a feed drive unit is provided with a plural gate unit connected between the input source and each of the plural output devices. The plural gate circuit units are disabled in response to the power failure or shut-off for jointly holding all the output devices electrically deenergized, respectively. A sequential trigger circuit operates in response to a recovery from the power failure or shut-off for sequentially producing a plurality of trigger signals and enabling the plural gate circuit units therewith respectively whereby to commence energizing the respective output devices in a predetermined sequence.</p> |