Abstract: Battery charging time is shortened. The control circuit 6 controls the switches 7-1 and 7-2 to charge the batteries 21-1 and 21-2 at a constant current one by one. Subsequently the batteries are charged one by one at a constant voltage until the charging current decreases to 1/2 a prescribed current. Next, the control circuit 6 turns the switches 7-1 and 7-2 on to charge simultaneously the batteries 21-1 and 21-2 in a parallel connection. After the charging current decreases to a prescribed current value, the batteries are charged at a constant voltage for a prescribed time. Then charging is completed.

Abstract: A surveillance video tape recorder has a pair of video heads secured on a rotary drum at different heights in the direction of the axis of the drum, a capstan drive circuit connected to a capstan motor for driving a magnetic tape at a substantially constant speed in a search mode, a head switching circuit connected to the pair of video heads for alternately deriving reproduced output signals therefrom, a tracking signal generating circuit for generating a tracking error signal from tracking pilot signals included in the reproduced output signals and from a reference pilot signal, a head switching pulse generating circuit for generating and supplying a head switching pulse to the head switching circuit and a gate circuit connected between the tracking signal generating circuit and the capstan drive circuit.