Title: Speed shift indicator

• Summary
• Claims
• Description
• View all

Abstract: A speed shift indicating device is mounted in the driver compartment of a motor vehicle and is connected to the ignition system by a single wire which extends from the driver compartment through the firewall and into the engine compartment. The single wire derives from the ignition system an electrical input signal having a repetition rate indicative of engine revolutions per minute (RPM). The speed shift indicating device has an electrical circuit connected to the single wire for receiving an input electrical signal which has a repetition rate indicative of engine RPM. Trigger pulses are produced in response to the input electrical signal and are supplied to a timer. The output of the timer switches to a first state in response to each trigger pulse and remains in the first state only for a first time period unless another trigger pulse is received before the end of the first time period. The first time period is adjustable by the driver. An annunciator is energized to indicate that the engine has attained a speed at which shifting of the transmission should be done only if the output of the timer remains in the first state for at least a second time period which is greater than the first time period.


Do you think this is a good invention? Vote now: