U.S. Philips Corporation

Michael Ramm

Jurgen Kordts

Ralf Beier

Axel Nathe

Georg Kisters

A controlled power supply source is described, which has a parallel control member having a controllable semiconductor component whose load path is arranged between output terminals of the power supply source and whose control input is connected to an output of a control device, the control device having a reference input for supplying a reference voltage. The control device has a control amplifier which is fed from a current bank having at least one constant current source, an actual value input of said control amplifier receiving the voltage between the output terminals of the power supply source, and a nominal value input receiving the reference voltage from the reference input of the control device. An output of the control amplifier constitutes the output of the control device which further has a preliminary current stage which, dependent on the difference between the voltages at the actual value input and at the nominal value input of the control amplifier, applies a preliminary current to this control amplifier, which preliminary current is applied to the control input of the semiconductor component at least partly via the output of the control device. This provides the possibility of controlling high power supply voltages, and when the source is switched on, only a very short period of time is required to reach the linear operating range of the parallel control member.

Controlled power supply source

A processing circuit for a magnetoresistive rotary speed sensor (13) or the like having a comparator (11) with switching hysteresis for converting an analog sensor signal into a digital switching signal. An apparatus is provided at the input side of the comparator in order to alternately supply each of the comparator inputs, as a function of the switching signal at the output side of the comparator, symmetrically with a given hysteresis signal as a switching threshold. This apparatus also includes a preamplifier (15) which precedes the comparator non-inverting input and which amplifies the sensor signal, and an offset amplifier (18) of the same construction which precedes the comparator inverting input and which amplifiers an offset signal of a preceding offset network (21). The processing circuit provides a simple, integrable circuit which suppresses offsets and compensates for temperature and supply voltage fluctuations and any spread in tolerances of the circuit components.

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Hamburg, Germany

Michael Ramm