Circuit arrangement for monitoring the phase sequence of a rotary field

Claim 2

A circuit arrangement for monitoring the phase sequence of a rotary field, comprising: a voltage comparator for receiving first half waves from two-phases and the opposite half wave of a third phase, inverted, and responsive thereto to form a measuring voltage; means for providing an inverted half wave of the third phase as the reference voltage to said comparator; and means for adjusting said voltage comparator to provide an error signal indicating an erroneous phase sequence when the reference voltage exceeds the measuring voltage.

Claim 3

The circuit arrangement of claim 1, comprising an RC circuit connected to said voltage comparator at the input which receives the non-inverted half wave forming the reference voltage.

Claim 4

The circuit arrangement of claim 1, comprising: a plurality of diodes, each of said diodes including a first terminal for receiving a respective phase and a second terminal connected in common with like terminals of the others of said diodes to provide a first input to said first voltage comparator.

Claim 5

The circuit arrangement of claim 1, comprising: first, second and third diodes, each of said diodes having first and second terminals; said first terminals of said first and second diodes adapted to receive respective phases in a non-inverted form and second terminals connected in common to a first input of said voltage comparator; and an inverter having an output connected to a second input of said voltage comparator, and an input connected to said third diode.

Claim 6

A process for monitoring the phase sequence of a rotary field, comprising the steps of: applying first half waves from first and second phases to one input of a comparator to form a measuring voltage; applying an inverter half wave of a third phase to another input of said comparator as a reference voltage so that said comparator provides an error signal indicating an erroneous phase sequence when the reference voltage exceeds the measuring voltage; applying the error voltage to an integrator; applying the output of the integrator to an operational amplifier; applying the output of the operational amplifier to a display circuit; providing the first, second and third half waves, through respective diodes, to an input of the additional operational amplifier; developing a second input signal for the additional operational amplifier by way of a voltage divider to form a comparator voltage; and applying the output of the additional operational amplifier to an input of the first-mentioned operational amplifier.

Claim 7

A process for monitoring the phase sequence of a rotary field, comprising the steps of: applying first half waves from first and second phases to one input of a comparator to form a measuring voltage; applying an inverter half wave of a third phase to another input of said comparator as a reference voltage so that said comparator provides an error signal indicating an erroneous phase sequence when the reference voltage exceeds the measuring voltage; applying the error voltage to an integrator; applying the output of the integrator to an operational amplifier; applying the output of the operational amplifier to a display circuit; providing the first, second and third half waves, through respective diodes, to an input of the additional operational amplifier; developing a second input signal for the additional operational amplifier by way of a voltage divider to form a comparator voltage; and applying the output of the additional operational amplifier to an input of the first-mentioned operational amplifier.

Claim 8

A three-phase monitoring process according to claim 5, wherein the step of developing a comparator voltage is further defined as: providing a luminous diode in the voltage divider.

Claim 9

A three-phase monitoring process according to claim 5, comprising the step of: applying the output of the first-mentioned operational amplifier to an optocoupler.