%0 Journal Article %J Electrotechnics & Electronics %D 2012 %T High Voltage Stability Measurements %A Martin Zobač %A Ivan Vlček %A Stanislav Šidlo %A Ivo Ungerman %C Sofia, Bulgaria %I The Union of Electronics, Electrical Engineering and Telecommunications %K high voltage %K measurement %K stability %N 5-6 %P 75-78 %V 47 %X Stability of the accelerating voltage is essential for the correct operation of electron-optical devices. Any periodic and/or random changes in the high-voltage alters the energy of the electrons; thus, affecting their trajectories and resulting in a blurred beam spot. This paper deals with the design of a precise voltage divider for accurate high-voltage measurements (up to 120 kilovolts). A resistive divider enables voltage measurements in the sub-hertz band. An additional capacitance divider allows for the quantification of both the AC ripple and noise voltages in the 25 Hz to 100 kHz band.