BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to a method and device for open-loop speed control of an electrically driven toy car on a lane-guided racetrack.

[0003] 2. The Prior Art

[0004] The speed of toy cars on a racetrack is usually adjusted by a hand-held closed-loop controller, which is generally pistol-shaped, and which enables open-loop speed control of the toy car between a zero position and a maximum position. Because of excessive acceleration of the toy cars, especially by inexperienced players, the tracks, cars and surroundings of the tracks can be damaged, especially by cars flying out of the curves. The traditional means of preventing this was to provide a transformer, with which the basic speed of the car could be controlled by the open-loop technique. New regulations have been enacted for toy cars for children, however, and the use of such transformers is no longer permitted.

[0005] It is further known, especially in the case of remotely steered toy cars, that the running speed can be adjusted up to a certain value in a first closed-loop control range and, after actuation of a so-called boost key, a higher speed can be reached. The boost key can be designed as a separate key, but it can also be constructed so that after a first speed level has been reached, the open-loop speed control key must overcome an obstruction in order to reach the second speed range.

[0006] There are also known toy cars whose function is adjustable by operation of programming keys. For example, programmable running behavior of the traveling toy can be achieved by a string of different commands input via typing keys in a keyboard arrangement.

[0007] Finally, it is known that traveling toys can be controlled by the open-loop technique by driving their motors electrically via a pulse-width open-loop controller, in order to achieve closed-loop control of the running speed.

SUMMARY OF THE INVENTION

[0008] It is therefore an object of the invention to provide a method and device for open-loop speed control of an electric toy car on a lane-guided racetrack, to permit the adjustment of different speed levels without the use of a transformer, ensure high safety and permit great playing enjoyment.

[0009] The invention relates to a method for open-loop control of the speed of an electric toy car on a lane-guided racetrack via a hand-actuatable closed-loop control device. The speed of the toy car can be adjusted to at least two speed levels. The second speed level can then represent the maximum attainable speed, which is achievable based on the electronic system, the voltage supply, the mechanical construction and the condition of the track and car. In the range between zero position and the second speed level, the magnitude of the first speed level can be programmed by the closed-loop control device to be a fraction of the second speed level.

[0010] By means of an open-loop control device, the speed of the toy car can then be adjusted between a zero position and the first speed level, and by actuating a selection switch the speed of the toy car is adjustable between the zero position and the second speed level. Given appropriate definition of the speed levels, the open-loop control device can therefore adjust the speed of the traveling toy between the zero position and the first speed level during regular play. Only when a selection switch, which can be a boost key, for example, is pressed, is the speed range increased to between the zero position and the second speed level.

[0011] With the present invention, the selection switch or boost key must be additionally actuated to reach the second speed level. Thus in normal play, the risk of cars flying out of the track or of damage to the surroundings is decreased.

[0012] In a preferred embodiment of the invention, further speed levels can be programmed or selected between the zero position and the second speed level.

[0013] Adjustment of a speed level is achieved preferably by programming a microprocessor.

[0014] The second speed level can be reached by a single actuation of the selection switch, but in a preferred embodiment, the second speed level is reached gradually, and only as long as the selection switch is simultaneously actuated.

[0015] The magnitude of the speed levels is determined, for example, by programming, preferably by manual actuation of function stages of a momentary-contact switch on the closed-loop control device. The magnitude of the speed level is then stored by actuating a separate switching means. The function stage of a momentary-contact switch can be reached, for example, by pressing a boost key for longer than 5 seconds. By alternating actuation of plus and minus keys of the open-loop control device, it is possible, for example, to select a specified speed level. This value can then be stored in a memory of a microprocessor device by once again actuating the boost key for sufficient time.

[0016] The respective functions of actuation can be shown on a display device, wherein two LEDs can be provided for assistance.

[0017] In the device according to the invention, there is a closed-loop control device with a microprocessor for programmable definition of at least two speed levels of the toy car. There is also an open-loop control device for adjustment of the speed of the toy car from a zero position up to a selected speed level. By means of a selection switch, the speed level can be selected for the open-loop control device.

[0018] The toy car is driven by pulse-width modulation controllable by the open-loop technique, in which a selected stored speed level represents the maximum value of the speed of the toy car that can be achieved with the open-loop control device via adjustment of the pulse-width modulation.

[0019] The present invention allows safer play without use of a transformer and without restriction of function. The programming capability of the closed-loop control device also permits expanded adjustment capabilities for different speed levels. It is also possible to add running characteristic curves such as acceleration profiles or braking profiles to the selectable speed levels. The toy car therefore behaves in conformity with the selected input information during adjustment of a particular speed level.