The FJ20 from KGS is a pulse width modulated AC to AC power inverted that provides regulated 0 to 5 VAC at 400 Hz power up to 40 amps. The output voltage is controlled by a 0 - 5 Vdc slider voltage applied at pin M from a 10k potentiometer 1/2 watt to ground or directly from a 0 - 5 VDC source.