DC current brushless motor driving apparatus and air conditioner with using thereof

Year	Description
2000	Invention patented by Toyomitsu Wakui, Kouji Katou, Atsushi Okuyama, Hideki Terauchi, Minoru Makita, Kisasu Kaneko, Masayuki Iwasaki, and Kenji Tamura on April 24th, 2000. Abstract: For detecting commutation timing of an inverter when operating a DC brushless motor under a starting thereof or a light load condition, with certainty, a micro-computer generates driving signals so as to drive switching elements of the inverter by PWM signals of those driving signals, in a predetermined order by every turn-on interval, thereby supplying driving current to the DC brushless motor, wherein a timing for exchange between the turn-on intervals (i.e., the commutation timing) is detected by detection of level of magnetic pole position detecting signals upon a basis of the PWM signals. Here, the minimum ON time of the PWM signals is set at a time being detectable in the level of the magnetic pole position detecting signals, however the frequency of the PWM signals is lowered when the DC brushless motor is operated in starting or under a light load condition, so as to make duty ratio of the PWM signals fit to the operation in the starting or under the light load condition, thereby enabling to ensure the minimum ON time of the PWM signals.
Source: selected by the editor from original sources.

Invention: DC current brushless motor driving apparatus and air conditioner with using thereof