The AC1000 is an innovative, low cost, pure power source designed specifically for use with a harmonics analyser such as the TTi HA1600, permitting compliance quality measurements to EN61000–3–2. The AC supply available at a standard wall socket is usually distorted. This comes about because of nonlinear loads (non–resistive loads) on the AC supply such as transformers, fluorescent lights, switched–mode power supplies etc. In a typical load there are rectifiers and capacitors that cause current to be drawn from the supply only near the peak of the waveform. The effect of this is to flatten off the top of the sine wave causing significant distortion. In a typical factory environment this distortion can be so significant that it is easily visible using an oscilloscope. EMC legislation (EN61000–3–2) has made mandatory the measurement of harmonic current produced by electronic equipment, and requires that the source supply provides a pure voltage waveform to the equipment under test. The harmonic currents can differ significantly when a pure source is used so it is important that any testing is performed with a device such as the AC1000. Compact and portable the AC 1000 is rated up to 1000 V·A for 230 V operation and will supply 1000 V·A at 230 V input at up to 35°C ambient. In contrast to other techniques which use a passive filtering approach, the AC1000 uses an innovative technique which actively corrects the AC supply to produce a harmonically pure output. The AC1000 is also very useful for stress testing power supplies in electronic equipment. The use of a harmonically pure, distortion free device – such as the AC1000 – is essential to fully stress and evaluate the power supply under test.