Highly reliable & durable devices that generate a power supply of 230 V AC at a frequency of 50 Hz from a 12 V or 24 V DC (for instance, from batteries in cars, boats, on a camp site, in garden houses...). The very high inductive load capacity enables electric motors, mobile offices (laptops, etc.), fridges, electronic tools, etc., to be operated. These devices naturally conform to the highest quality & safety requirements & are equipped with overload, overheating, short-circuit, deep discharge & undervoltage protection. As soon as the input voltage sinks below 10.7 V or 21 V the devices trigger an alarm. If the voltage drops below 10 V, the devices switch themselves off. These protection mechanisms optimally protect the power supplies (batteries) as well as the connected devices.