Abstract: Drive and steering unit for a wheel of a floor conveyor, in which a driving motor and a steering motor are disposed coaxially one below the other and are each one coupled via a drive gear or a steering gear, respectively, with a shaft of the wheel or the bearing equipment of the wheel, respectively, wherein one shaft extends as a hollow shaft and the other shaft extends through the hollow shaft, and an electronic control for the driving motor and the steering motor, which is connected with desired value transmitters for the rotational speed and the steering angle, characterised in that the electronic control has at least one circuit board which is coaxially arranged between the driving motor and the steering motor and/or the steering motor and the steering gear.

Abstract: In order to control a power semiconductor which can be triggered into conduction by pulses of one polarity and quenched again by pulses of the opposite polarity, by transmitting such pulses via a transformer to the power semiconductor connected at the secondary side of the transformer, such a pulse is formed by turning on a first transistor connected between one pole of a voltage source and a tap which divides the primary winding of the transformer into two partial windings, and by selectively turning on either one of second and third transistors each connected to the ends of a respective partial winding, and such a pulse is terminated by switching off the first transistor, while maintaining on the selected second or third transistor in order to cause the demagnetization current of the transformer to flow through the selected transistor and through a Zener diode connected between the tap of the primary winding and the other pole of the voltage source, the anode side of the first Zener diode being connected to