| 摘要 |
<p>PURPOSE:To make the supply of power stable by providing a means switching an under-cut means to be turned off in the case of using an on-vehicle power supply and the under-cut means to be turned on in the case of using a battery pack. CONSTITUTION:An under-cut detection changeover section 11 is interposed between an under-cut detection section 7 and a power supply control section 6 and the under-cut detection changeover section 11 is turned on/off in interlocking with the switching of a power supply changeover section 12. That is, in the case of using an on-vehicle power supply 1, the power supply changeover section 12 switched to the position of the power supply 1, resulting in turning off the under-cut detection changeover section 11 in interlocking therewith. Even when an under-cut detection section 7 detects it that the voltage of the power supply 1 is a prescribed voltage or below, the power supply control section 6 is not active and the power from the power supply 1 is continued. In the case of using a battery pack 5, the power supply changeover section 12 is thrown to the position of the battery pack 5 and the under-cut detection changeover section 11 is turned on in interlocking therewith. Thus, even when the on-vehicle power voltage is decreased, the power is always stably ensured and the device operation is continued.</p> |
