Speed control for toy sailing boat - has light bulb illumination of transparent disc, compass needle, aperture slot and photoresistor

摘要

The device enables the operator of a model sailing boat to simulate the direction and speed of the boat to be expected in consequence of wind and sail conditions. It comprises a small light bulb (1) shining through a rectangular slot (2) onto a circular disc (3) of variable transparency. The transparent disc carries markings according to the type of sailing boat in operation, and lies immediately above a compass needle (5) which follows magnetic North and South bearings. Beneath the needle is a second slot (2) collinear with the first and guiding the light beam to fall upon a photo-resistor (4). The latter is in circuit with transistor circuit powered by a battery.