Abstract: The invention relates to an electric circuit for measuring the length of a shock absorber unit of a vehicle, comprising: a coil with windings which are fitted around the shock absorber unit, of which a casing of electrically conducting material connected to a part of the wheel suspension of the vehicle is axially movable relative to the coil when there is a change of length of the shock absorber unit as a result of a change in the force absorbed by the wheel suspension; an oscillator connected to the coil, for exciting the coil with an excitation signal of a predetermined frequency; and processing means which are connected to the coil and are designed for determining the value of a relation between the voltage across the coil and the current through the coil, which value is a measure of the length of the shock absorber unit.

Abstract: A control system for supplying a gas flow to a gas consumption apparatus, comprising a gas supply pipe which can be connected to the apparatus and which has an electrically controlled gas control valve, and an electronic control unit. The control unit comprises a mathematical module, model-related to the control valve, for adjusting the valve position, and the gas control valve has in-built sensors for gas variables and valve position, the control system adjusting the control valve in linear proportion to a desired gas-flow signal to be supplied to the control unit. The mathematical module comprises a flow submodule, a mechanical submodule and a valve-position submodule, and the flow submodule receives, at its inputs, the desired gas-flow signal and gas variables originating from the valve sensors and supplies, at its output, a signal relating to the through-flow area of the valve, to the mechanical submodule.