Abstract: A system for capacitively detecting the presence of a tape cassette within a vending machine or the like. The testing system within the machine employs an ac source connected to a source electrode and a detector connected to a detector electrode. A coded pattern is provided along the side wall of the cassette with a pair of series connected electrodes arranged to oppose the electrodes of the testing system. When aligned, the capacitances formed between the testing system electrode and the coded pattern complete an electrical circuit from the source to the detector through the cassette. The completing of the circuit indicator the presence of the cassette.

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 valve for use in the automatic control of a vehicle and which may conveniently be powered from a vehicle speed monitoring electronic system. It is essentially a solenoid operated valve for vehicle control comprising a hollow body of non-magnetic material having an inlet and an outlet axially aligned with each other, valve seats at the inlet and outlet, a piston of magnetic material slidable in said body between positions closing the opening through either one or other valve seat, and a bore through the piston and in communication with a normally open outlet from the body. A considerable constriction is provided between the piston controlled inlet and the outlet from the body. The normally open outlet is suitable for connection to a vacuum operated servo-mechanism, the piston controlled outlet is suitable for connection to the vehicle engine vacuum line and the inlet is open to ambient atmosphere.

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.