摘要 |
Steering wheel oscillations are detected and a first signal generated for each predetermined number of oscillations. A ramp generator is reset by each first signal and, if its output reaches a preset value, a comparator generates a second signal to indicate excessive time between first signals. An up-down counter is counted up by each first signal and down by each second signal. A comparator compares the contents of the counter with a present number and generates a third signal when the number in the counter falls below the present number. A timer consisting of an integrator and comparator generates a forth signal when the third signal has been present for a predetermined time. The forth signal causes an alarm device to alert the driver.
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