Abstract: In the embodiments described in the specification, a device having gear teeth to provide magnetic asymmetries rotates adjacent to a permanent magnet which is part of a mechanical mounting for a piezoelectric transducer. Relative motion between the gear teeth and the magnet subjects the transducer to a varying mechanical stress so that it generates a pulsed output voltage signal having an amplitude which is independent of surrounding influences.

Abstract: A device for continuous injection of fuel into the intake line of a multi-cylinder mixture-compressing internal combustion engine is described, the said engine comprising an air pump (9) delivering a carrier air current branched off the intake line (2) and a fuel pump (4) which delivers the fuel from a fuel tank (3) to a metering device (7), apportioning the fuel to the carrier air current as a function of the operating state of the internal combustion engine. In order to ensure the best possible uniform and precise metering of the fuel of the fuel to the individual cylinders of the internal combustion engine, means for dividing the carrier air current among the carrier air injection lines (29) separately associated with the individual cylinders of the internal combustion engine are to be provided. Furthermore, the metering device is to be constituted by an injection valve (7) with injection lines (1) (36) each separately associated with the carrier air injection lines (29) and opening into the same (FIG. 1).