Apparatus for charging an electrical energy store from an AC voltage source, having: - a rectifier device, which can be electrically connected to the AC voltage source, with a capacitor interconnected in parallel with the rectifier device; - a current controller device interconnected with the rectifier device; - a converter device interconnected with the current controller device via an inductor, said converter device having at least one first half-bridge comprising two switches (S1, S2) connected in series; - wherein the two switches connected in series consist of a first switch and a second switch; - wherein the electrical energy store for storing electrical energy is connectable to an output of the converter device, and - wherein the inductor is interconnected with a connection point of the switches (S1, S2) of the first half-bridge; - wherein, depending on the voltage of the AC voltage source and a current through the inductor, the switch of the current controller device and the second switch of the first half-bridge of the converter device are switchable by means of a controller in such a manner that a current for charging the electrical energy store drawn from the AC voltage source and a voltage (U AC) of the AC voltage source are substantially in phase; characterized in that the current control device consists of a switch and a diode which is operated in the reverse direction, wherein the second switch is connected to the cathode of the diode operated in the reverse direction, and in that the controller is configured in such a manner that - if the voltage (U AC) of the AC source is greater than the voltage of the electrical energy store, the switch of the current control device and the second switch of the first half-bridge are clocked, wherein a back-EMF to the inductor, which drives a charging current for the electrical energy store via a freewheeling diode connected in parallel with the switch, is built up by means of the clocked actuation of the second switch of the first half-bridge and the switch of the current control device; and - if the voltage (U AC) of the AC source is less than the voltage of the electrical energy store, the switch of the current control device is permanently closed and only the second switch of the first half-bridge is clocked. - a rectifier device, which can be electrically connected to the AC voltage source, with a capacitor interconnected in parallel with the rectifier device; - a current controller device interconnected with the rectifier device; - a converter device interconnected with the current controller device via an inductor, said converter device having at least one first half-bridge comprising two switches (S1, S2) connected in series; - wherein the two switches connected in series consist of a first switch and a second switch; - wherein the electrical energy store for storing electrical energy is connectable to an output of the converter device, and - wherein the inductor is interconnected with a connection point of the switches (S1, S2) of the first half-bridge; - wherein, depending on the voltage of the AC voltage source and a current through the inductor, the switch of the current controller device and the second switch of the first half-bridge of the converter device are switchable by means of a controller in such a manner that a current for charging the electrical energy store drawn from the AC voltage source and a voltage (U AC) of the AC voltage source are substantially in phase; characterized in that the current control device consists of a switch and a diode which is operated in the reverse direction, wherein the second switch is connected to the cathode of the diode operated in the reverse direction, and in that the controller is configured in such a manner that - if the voltage (U AC) of the AC source is greater than the voltage of the electrical energy store, the switch of the current control device and the second switch of the first half-bridge are clocked, wherein a back-EMF to the inductor, which drives a charging current for the electrical energy store via a freewheeling diode connected in parallel with the switch, is built up by means of the clocked actuation of the second switch of the first half-bridge and the switch of the current control device; and - if the voltage (U AC) of the AC source is less than the voltage of the electrical energy store, the switch of the current control device is permanently closed and only the second switch of the first half-bridge is clocked.