THE new Alcon range, available from Westek Electronics , is a series of self-healing, aluminium foil/polypropylene dielectric capacitors suitable for high voltage, high current, and high dv/dt applications. These include IGBT protection, snubber networks and protection of power electronics including switch-mode power supplies.
The Alcon range covers terminal-mounted capacitors in voltages ranges from 1000 to 2000V dc (capacitance range from 0.1 microfarad to 3.3 microfarad), and flying-lead devices in voltage ranges from 850V dc to 2000V dc (capacitance range from 0.015 microfarad to 1.5 microfarad).
The alcon capacitors can be specified in capacitance tolerance ranges of 5% and 10%. The alcon capacitors are characterised by low self-inductance, low equivalent series resistance (ESR) and very low loss angles. As an example tan varies from 170ppm at 1kHz to 6000ppm at 1MHz.
Temperature stability is also excellent with typically only a 3% change in capacitance from -55°C to +100°C, and capacitance stability as a function of frequency is 1% over the range of 1kHz to 1MHz.