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.

Abstract: An anti-theft device for an automotive vehicle in which an electronic engine speed responsive means is effective, when said anti-theft device has been prepared for operation by closure of a concealed switch, to disable the engine after the engine reaches a predetermined speed and to maintain the engine disabled until the concealed switch is reopened. The device may also energize the horn relay so that the horn sounds while the engine is disabled. The electronic speed responsive device can be connected across the points and the circuit components all can operate at vehicle battery voltages so that the anti-theft device can be quickly installed in a vehicle. The engine disabling means can be maintained in operation either through the use of an electronic trigger switch or by the use of a relay which establishes its own holding circuit.

Abstract: An ignition retarding device which cuts off the usual vacuum ignition advance to retard the ignition when the brakes are actuated or when the engine speed drops below a predetermined value, there being a further device responsive to engine temperature to restore the vacuum ignition advance whenever the temperature of the engine rises above a predetermined value. The speed is measured by an electronic tachometer whose input is connected across the distributor points and whose output is fed through a voltage comparator and an amplifier to control the energization of an electrically operated valve. The override brake and temperature signals are obtained by connections to the usual brake switch and temperature switch. Provision is made for use of the equipment with automotive vehicles either in which the brake switch is between the brake light and ground or between the battery and the brake light.