| 摘要 |
PURPOSE:To protect an automatic transmission from any damage resulting from improper operation of speed changing means caused by the driver's neglectful or careless behavior of shifting a gear range into an unexpected position during forward or reverse driving by providing a unique operating circuit between a car speed sensor and an electromagnetic means control circuit. CONSTITUTION:When a speed sensor 1 generates an output, an AND gate receives signals of H at both the input-side thereof and generates the signal of H at the output-side thereof. The pulse is then sent to a frequency-to-voltage converter 4-1 and it generates a voltage corresponding to the frequency namely, the car speed. If the voltage is over a threshold level of an inverter gate 13-2, namely, if the car speed is high, the gate 13-2 generates a signal of L at the output terminal thereof and the signal of L is applied to one of the input terminals of an AND gate 3-3. Because of the reason, even if reverse switch 7 is kept on, the output of the AND gate 3-3 is remained L so that a motor driving circuit 5 generates no output. A servo motor 6 will not be operated reversely. |
