current drawn from the ac source 103 is allowed at all times during a ramp in course this maximum value is increased linearly from zero to a predetermined maximum value within a predetermined period e g 10 seconds if it is desired to supply more current or power than allowed by this maximum value there is formed on the one hand half wave shaped sinusoidal signals with the maximally allowed value whereas the remainder of the power need is covered by current pulses from the battery the distribution between the two pulses is calculated continuously such that they combine to cover the need for supplied power correspondingly this limitation of ac current pulses is used to delimit the current from a current network or diesel generator during overload also in this case it is calculated how much supplement is needed from the battery to deliver the requisite total amount of power if the node 118 is split and if the ac source 103 and the switch 127 are connected instead to the alternating current inputs of a rectifier bridge where the positive output of the rectifier bridge is connected to the anode on the diode 119 and the negative output of the rectifier bridge is connected to the cathode on the diode 120 it is also possible to obtain supply from the ac source 103 in both half periods to both the positive half and the negative half of the converter 100 hereby the.