Abstract: A gas discharge lamp ballast circuit operates at high frequency and is fed from a mains supply through a rectifier having a smoothing capacitor. The invention provides for the load to include an inductor and to return to the rectifier supply at a position isolated from the smoothing capacitor by one or more diodes, and for there to be a discharge path from the smoothing capacitor through the load to charge a control capacitor, and lower the load voltage to allow a rectifier current flow to the load. The smoothing capacitor is charged by current flowing from the inductor during a relaxation phase, to a voltage higher than the peaks of the rectifier. The smoothing capacitor voltage is maintained by proportioning the control capacitor size to cause rectifier current, and not smoothing capacitor discharge, to supply circuit and load losses.

Abstract: A servo apparatus for automatic control of vehicle engine speed, in accordance with a speed error signal, has an electric motor connectable to open the engine throttle against a restoring force, and the motor torque is controlled by varying the pulse width of the motor drive current. The pulse width is controlled by the error signal through a feedback stabilized amplifier and in addition, motor back emf is sampled and used to control the pulse width during motor braking phases.

Abstract: This invention relates to a method of and apparatus for controlling the operation of a vehicle by means of electrical signals generated in a manner dependent on the road speed of the vehicle wherein the method comprises setting up a specific magnetic field in association with a normally unmagnetized component of the vehicle which rotates at a speed proportional to the road speed of the vehicle and sensing variations in the magnetic field in a coil located on the opposite side of a ferromagnetic member of the vehicle to the component and amplifying the signal through a high gain amplifier.

Abstract: A method of and apparatus for controlling the operation of a vehicle by electrical signals generated in a manner dependent on the road speed of the vehicle wherein the method comprises setting up a specific magnetic field in association with a normally unmagnetized component of the vehicle which rotates at a speed proportional to the road speed of the veicle and sensing variations in the magnetic field in a coil located on the opposite side of a ferromagnetic member of the vehicle to the component and amplifying the signal through a high gain amplifier.

Abstract: This invention relates to a method of indicating changes in the rate of fuel consumption in internal combustion engines from a predetermined rate utilizing as a basis a predetermined vacuum in the engine manifold and using variations from such vacuum to operate a switch mechanism in at least one electrical circuit for a display means which indicates when the vacuum is above or below or at the predetermined level.