These series connected disc capacitors have been developed for use in low power voltage multipliers for high voltage DC generators. These devices find their major application in the manufacture of voltage multipliers for electrostatic paint spraying equipment and their compact form lends itself to their incorporation in hand held electrostatic spray guns.
A number of capacitors are assembled together with intermediate fittings which allow the connection of diodes to be made. Output voltages in excess of 100kVDC can be produced depending on the number of stages.
Voltage ratings of individual discs range from 8 to 12kVDC assuming that the quality of encapsulation by the user is sufficient to prevent external breakdown.
A variety of intermediate metal fittings are available and the number of individual capacitors in each stack can be varied to meet customers requirements up to a maximum of 12.
Dry powder paint spraying in automotive white goods or any other metal products requiring smooth uniform paint finish.
High Voltages can be produced from a relatively low voltage AC source using a Voltage Multiplier Assembly i.e. parallel stacks of series connected capacitors and cross connected diodes. These devices find their major application in electrostatic paint spraying equipment.
DC output voltages in excess of 100kV generate a corona discharge at the end of the spray gun and the resulting HV electric field causes the surrounding air to break down creating negatively charged ions. The ions attach themselves to the nearest object or surface and the particles of paint powder passing through this field become charged then attracted to the earthed work piece.
The capacitor stack assembly consists of a number of series connected capacitor discs with a choice of intermediate metal fittings to which the diodes are attached.
A wide range of stacks of up to 12 discs in series are available with voltage ratings of the individual discs from 8 to 12kV DC and capacitance values from 125pF to 1000pF.
Their compact size, low weight and ability to withstand the high voltages generated are the main reasons why these assemblies are used.