Abstract: A mains rectifier circuit for power supply units, in particular for switched-mode power supplies, having a full-wave rectifier (D1 . . . D4) which is connected to the mains voltage and having a smoothing capacitor (CL) which is connected downstream of said full-wave rectifier (D1 . . . D4), the smoothing capacitor being charged at a clock frequency, which is considerably higher than the mains frequency, via the series circuit formed by a boost inductance (LB) and a diode (DS), in the case of which series circuit the junction point between the boost inductance and the diode is connected to earth via a controlled switch (SB), the smoothing capacitor (CL) and the load (SNT) are connected to the full-wave rectifier (D1 . . .

Abstract: A device for controlling the field current of a DC motor supplied from an AC network and which is operated beyond the normal speed of the DC motor in the higher speed range obtainable by weakening of the field of the DC motor, there being provided for the apportioning of the field current of the DC motor a phase angle control circuit which is operated depending on a control variable obtained from the respective measured speed of the DC motor by a function-forming device as a function of the speed, the function-forming device comprising a function memory which contains values of the control variable correlated to individual speed values stored in a matrix in tabulated form, the correlation of these values individually corresponding to the DC motor being established when the DC motor starts up for the first time, and where a constant dependence of the control variable on the speed is established either by a polygonal line obtained by linear interpolation from the value pairs stored in tabulated form or by a cur

Abstract: In a reversible d-c controller, a current transformer having two primary windings as current measuring sensors is provided for determining the load current. The primary windings are connected with opposite winding sense into two diagonally disposed bridge arms of a controller bridge circuit. The secondary winding of the current transformer is coupled through a full wave rectifier and across a load resistor to the input of a sample-and-hold stage which is provided with an electronic sampling switch and at the output of which a signal proportional to the actual value of the load current is present. The bridge circuit comprises 4 bridge arms, each bridge arm having an electronic switch and a reverse biased diode shunted across the switch. Each pair of bridge arms connected to the same side of the power supply buss and coupled across the load form a bypass circuit.