Toy vehicle engine sound device

摘要

An engine-sound accessory for an electric toy vehicle produces a sound output which varies its characteristics in proportion to an electric input to the toy vehicle. The apparatus measures the total electric current fed to the toy vehicle to produce a sound control signal proportional thereto. When two or more vehicles are fed from a common power source, the apparatus is responsive to the sum of the electric current fed to the two or more vehicles whereby variation in the electric current fed to one or both of the vehicles produces a corresponding variation in the sound characteristic.