Telefunken Electronic Gmbh

Jurgen Sieber

Rolf Bohme

Heinz Rinderle

At a reference current source with two transistors and a controlled double current source, the base of the second transistor is connected to the collector of the first transistor, the emitter of the first transistor is connected to a reference point, the first terminal of the controlled double current source is connected to the first transistor, and the second terminal of the controlled double current source is connected to the collector of the second transistor. Either a first resistor is inserted between the base and the collector of the first transistor, and the emitter of the second transistor is connected to the reference point or the first resistor is inserted between the emitter of the second transistor and the reference point, and the base and the collector of the first transistor are connected to one another. A resistor is connected between the base of the first transistor and the reference point and/or a resistor is connected between the collector of the second transistor and the reference point.

Reference current source

A thermoelectric level measuring device for measuring the fill level of a container having a filling material therein and a free space above the filling material comprises a series connection of three sensing resistors, the first of which is always surrounded by the filling material, the second of which is intended to be surrounded by the filling material and by the free space and the third of which is always located in the free space and an evaluation circuit connected to each end of the series connection and to the connection points between the sensing resistors.

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Heilbronn, Germany

Jurgen Sieber