Abstract: A pulse generating system for a pulsed working fluid supply, comprising a pipe, a source of pressurized working fluid connected to the pipe, an angle-seat valve connected to the pipe, a source of pressurized control fluid, a pressure regulator connected to the source of pressurized control fluid, a three-port, two-position control valve connected to the pressure regulator and to the angle-seat valve and configured to control the angle-seat valve, and a control device configured to control the pressure regulator as a function of desired pulse amplitudes and to control the control valve as a function of desired pulse frequencies. The invention also relates to a washing machine comprising a system.

Abstract: A washing machine comprising a wash chamber, a wash solution tank, a spray bar, a pump, and a recovery tray; wherein the washing machine further comprises a heating pipe, a heat pump configured to heat the wash solution, the heat pump being configured to recover heat from air heated in the wash chamber and to transmit heat to the wash solution circulating in the heating pipe, and a control device configured to control the pump and the heat pump.

Abstract: An amplifier system comprising an input transducer, an amplifier and an output transducer connected in cascade, and an automatic gain control circuit comprising a variable resistor for taking off a voltage which varies with the signal from the input transducer and supplies said voltage to a rectifier and an RC filter. The filter output is connected to the base of a first transistor having a collector that directly drives the base of a second transistor which is connected to the input of the amplifier in such a way that it bypasses the input signal of said amplifier to a greater extent as the signal across the variable resistor increases.