Offset printing press having a main motor and dampening equipment includes a device for automatically controlling a supply of dampening liquid to the dampening equipment. The device includes an adjusting motor which has a rotary shaft and which is connected to the main motor for controlling the rotary speed thereof, a control cam secured to the shaft, as for example, illustrated in U.S. Pat. No. 2,561,837, and control member means operatively engageable by the control cam for determining the amount of liquid supplied from a source thereof to the dampening equipment.

A load in an electrical apparatus is driven by two motors M1, M2. Switching means (R1, R2) switches the motors M1, M2 between: a series configuration, in which the motors M1, M2 are connected in series across a power supply and driven with a dc supply; and a parallel configuration in which the motors M1, M2 are connected in parallel across the power supply and driven with an ac supply. In the series configuration, a bridge rectifier BR is switched across the ac supply to provide the dc supply for the motors M1, M2 and in the parallel configuration, the rectifier BR is removed from the circuit. The arrangement can be used to drive a drum of a washing machine or a load in some other kind of appliance.