| 摘要 |
<p>A programmable boatlift system having a cable (21) extending up from one end of a boatlift cradle (17), across to a shaft (19) attached to a motor (18), and down to an opposite end of the boatlift cradle (17). The cable (21) passes through a hole (31) in the shaft (19). A position sensor (24) having an idler sheave (25) is placed on the cable (21). The motor (18) winds or unwinds the cable (21) around the shaft (19) to cause the cable (21) to move across the roller sheave (25) to raise or lower the boatlift cradle (17). The position sensor (24) produces an output signal proportional to the distance the cable (21) travels over the idler sheave (25) as the cable (21) causes the idler sheave (25) to rotate. An electronic control circuit (26) uses the output signal to infer the vertical position of the boatlift cradle (17) and to position the boatlift cradle (17) as desired.</p> |
