| 摘要 |
<p>PURPOSE:To simplify the construction of a motor driven antenna for a vehicle and to obtain the practical use by automatically stopping it at an overload time due to a defect when a load is moved by the motor in a positive direction, outputting a reversely moving command to the load, and cyclically performing the operation. CONSTITUTION:Transistors 16a-16d form a bridge circuit, thereby composing a normal/reverse controller of a DC motor 4. When the base input of the transistor 16c is set to a high level, the transistors 16b, 16c are conducted to supply positive power from a power source positive electrode 13b to rotate the motor normally. When the transistors 16a, 16d are conduced, the motor is reversely rotated. When a power switch 24 is closed, the motor 4 is normally rotated and an antenna member finishes to rise, it becomes an overload, it is detected by a comparator 15, thereby turning OFF the power source. When the switch 24 is opened, the motor 4 is reversely rotated to lower the antenna member, becomes an overload at the end, is detected by the comparator 15, thereby turning OFF the power source.</p> |
