Abstract: A power amplifier connection comprises a switching amplifier and a proportional amplifier. The output signal from the switching amplifier and the output signal from the proportional amplifier are supplied to a summation member which, by addition of the two output signals, forms the resultant output signal of the amplifier connection. The switching amplifier is adapted to be controlled in dependence on the input signal of the amplifier connection in such a way that its output signal endeavours to follow the input signal. The proportional amplifier is adapted to be controlled in dependence on the deviation between the input signal and output signal of the amplifier connection.

Abstract: Weighing equipment for weighing a load which is included in a mechanical system with a natural frequency of oscillation which depends on the size of the load, for example in a crane, includes a transducer influenced by the load and which delivers a signal corresponding to the weight of the load. The equipment includes a tunable band exclusion filter connected to the transducer for filtering the signal, in which the signal influences the tuning of the filter so that its anti-resonance frequency follows said natural frequency of the oscillation.