Abstract: A method for determining a state of an inverter on the basis of a plurality of sensor values, each of which corresponds to a measured value created via an analogue sensor of a sensor unit. A clock signal, which has a plurality of identical clock pulses having two different clock states, is sent to each sensor unit. During one of the clock states of each clock pulse, a predefined reference value for each sensor unit is changed by the current measured value to an intermediate value by a predefined operation. During the other clock state of each identical clock pulse, the intermediate value for each sensor unit is changed by an auxiliary value up to the reference value by an opposite operation. During each remaining time span of said identical clock pulse, a first state and otherwise a second state is used as the relevant sensor value.

Abstract: A device and a method connect and reliably separate a voltage terminal of a drive inverter for an electric machine to or from a supply voltage. The device contains a connection and interruption circuit with two switching branches connected between a supply voltage terminal of the supply voltage and the voltage terminal of the drive inverter. A control and/or regulating device is programmed and/or the circuitry of which is configured to connect the supply voltage to the voltage terminal of the drive inverter via the switching branches and to deactivate one of the switching branches in a first test mode and to read a sensor signal from the switching branch while the other switching branch is activated and conducts the supply voltage to the voltage terminal of the drive inverter.

Abstract: An apparatus and a method actuate a frequency converter of an electric machine having a safety function, in particular a safe-torque-off (STO) function. Wherein, by a preferably clocked converter circuit, an electrically isolated output voltage is generated from an input voltage, from which output voltage a control signal is generated for the frequency converter for the operation thereof in accordance with standards and for triggering the safety function. An actuation signal is generated for a semiconductor switch which is periodically connected to the input voltage, and the output voltage is limited when the output voltage exceeds a switching threshold.