Abstract: A system for injecting a predetermined amount of additive fluid into a main stream of fluid which controls the amount of additive injected by a timing circuit. A pump continuously circulates the additive through a circuitous path having a valve which diverts the additive into the main stream. A control system receives signals from a turbine meter in the main stream and opens the valve a predetermined length of time at a frequency depending on the signals received from the turbine meter, thereby maintaining a constant concentration of the additive in the main stream.

Abstract: A valve operator circuit normally operates to compare the pulse rates of two trains of pulses and to step an associated valve open or closed depending on which of the two pulse rates is the higher. The circuit includes a manually-operated presetting arrangement which, when operated, causes the normal pulses to be inhibited from moving the valve, and causes the valve to move to a desired position.

Abstract: In a liquid dispensing apparatus, a train of control pulses are produced at a rate representative of equal fractional parts of a unit volume of the liquid being dispensed, and for each of these control pulses a divider gates to an output circuit a number of pulses (derived from a continuously-operating generator) digitally equal to the price per unit volume of the liquid being dispensed. The gated pulses appearing in said output circuit are counted in continuous fashion by a counter which, during a sustained operation, produces a resultant output pulse at the conclusion of every one thousand pulses fed to its input. These latter output pulses are fed to decade counters which drive the final display devices for exhibit or indication of the total price.

Abstract: An anti-hunting system for use with a valve operator circuit which compares two trains of pulses to place a valve in the correct position. The anti-hunting system includes a J-K flip-flop circuit receiving a clock pulse train having an absolute time relationship with the input pulse trains. Also included in the valve operator circuit is a system having a shift register for controlling the energizing of the leads to a stepping motor controlling the valve position.

Abstract: Pulses produced by a stream flowmeter, at a repetition rate proportional to the actual flowrate of a liquid, are compared in a counter arrangement with pulses whose repetition rate is the demand flowrate for this liquid. The circuit produces an alarm whenever the difference between the actual flowrate and the demand flowrate is greater than 6%, or 10%. The alarm is inhibited until after 45 seconds subsequent to startup of the blending system for which the said liquid serves as one component.

Abstract: A blending-type motor fuel dispensing apparatus operates to blend together, in various proportions, two liquid motor fuels (gasolines) of different octane ratings, to produce various grades of product. The quantity and cost displays, and also the automatic control of the blend during dispensing, are based upon the summation of two sets of pulses, the number of pulses in each set being proportional to the integrated flow rate of a corresponding one of the two fuels. The pulses are counted and multiplied by a price per gallon, which has been previously set for the grade being dispensed, to provide a cost display. A pulse comparison circuit, which compares pulses representative of the flow of one fuel with a percentage (settable for each blend) of the summed pulses, is used to control the proportioning of the two fuels.

Abstract: A circuit for detecting flow pulses in a fluid stream includes a thermistor placed in the fluid stream for sensing changes in the flow rate, an R-C filter in circuit with the thermistor for passing pulses having a specified minimum flow rate change, and a square wave generator for producing an output signal when the filter passes a pulse.