... , various type of autos etc.Total amount of actual work time be charged with follow, keeping watch on an investigation of ... current, it then starts record a work for time. These timers are divided into the 120V 60 Hzs and 240V 50 Hzs, two kinds ... the frequency of alternate current and be the alternate current as 60 Hzs, records a word(namely the word once rotated a word) for an hour, be the ...