Original poster: "Wall Richard Wayne by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rwall-at-ix-dot-netcom-dot-com> List, For those who purchased a 34 kv HVDC laser PS, has anyone actively varied the input drive to vary the HV output? Can a signal generator (max 5 vdc input) be used to vary the output? If so, what is max frequency response? RWW