One embodiment provides a vehicle voltage supply having a vehicle battery, a load with two voltage supply connections, a fuse in a path between the vehicle battery and one of the voltage supply connections of the load, and a clamping circuit transistor. The clamping circuit transistor can be switched in such a manner that the clamping circuit transistor produces a short circuit between voltage supply connections of the load in order to activate the fuse. An energy store is set up to store the energy needed to drive the clamping circuit transistor when producing the short circuit, and a charging circuit is set up to charge the energy store at least during the time in which the clamping circuit transistor does not produce a short circuit.