HV Caps Applications
Morgan Technical Ceramics Electroceramics is a leader in the design and manufacture of advanced ceramic products with over 50 years experience in the manufacture of electroceramic materials and components for high voltage applications.
Live-Line Indication
To indicate the presence of voltage and for fault detection on power frequency high voltage distribution switchgear (6.6kV-36kV systems).
The capacitor is connected directly to the HV line and a small current (low voltage signal) is passed which illuminates a neon lamp mounted on the front panel of the switch.
Alternatively the low voltage signal may be used to feed a sensing circuit which monitors for supply failure and circuit condition.
The capacitor is normally contained within a resin moulding. Usually the moulding is made by the switch manufacturers themselves in a shape to suit their own particular needs but Morgan Electro Ceramics can offer certain complete mouldings or can advise on suitable sources.
Electrostatic Spray Guns
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 workpiece.
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 100OpF.
Their compact size, low weight and ability to withstand the high voltages generated are the main reasons why these assemblies are used.
DC Power supplies
Encapsulated High Voltage capacitor discs of the type shown can be used in voltage multiplier circuits for high voltage low power DC supplies such as those used in Medical scanners, X-Ray equipment and electrostatic precipitators.
Parallel strings of series connected capacitors with cross-connected diodes can be used in the multiplier circuit.
The equipment is usually non-portable and made up of large capacitance units - typically 150OpF upwards with voltage ratings of 20 to 40W.
You may also find the following sections of particular interest if you are associated with HV applications:-
- Capacitors Tutorial and Guides
- RF Power Capacitor Applications
- Capacitors Product Range
- Voltage Multipliers
- Live Line Units
