| 摘要 |
PURPOSE:To prevent an engine brake from no working in such a way that when a vehicle speed detecting means is in trouble, it is coupled to a clutch except when it is involved in speed change operation. CONSTITUTION:Signals from an accelerator switch 41, a top gear switch 42, an engine revolution switch 43 are given as input to a trouble detecting circuit 51. Vehicle speed signals are given as input from a vehicle speed switch 44 to a trouble detecting circuit 51 and an NAND gate 64, and when the vehicle speed switch is in trouble, an NAND gate 57 in the trouble detecting circuit gives low level as output. In consequence, an NAND gate 61 is involved in high level, and when a speed change switch 45 is turned OFF, a clutch is coupled by means of turning ON a transistor 67 through NAND gates 62, 64. Since the clutch is coupled when the vehicle speed switch is in trouble, an engine brake can be available informing the driver of the trouble. |
