Programmable AC power source

The development of a 1 kVA AC power source is presented which provides programmable sinusoidal output voltages. Both, output amplitude and output frequency can be set over a large range. The desired values can be programmed via a keyboard and a display or from a personal computer. The power source operates at the 220 V/50 Hz/60 Hz mains and draws a sinusoidal current from the line. The output voltage is isolated from the input circuit. It is also possible to operate the power source without the mains because internal batteries are installed. The system consists of switched mode power electronics and thus operates at a high efficiency. Another feature of the system is that 3 single phase units can be synchronized to form a three phase voltage power source. The AC power source is very well suited for testing appliances, consumer products, motors or other equipment which has to be supplied by the single phase mains. It may also be used within a production line in order to check automatically whether the device under test operates reliably in the specified voltage frequency range