Knowles Extends Operating Life of Electronic Devices with New Arc Suppressor/Snubber Network Devices

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Knowles Corporation, a market leader and global provider of advanced micro-acoustic microphones and speakers, audio solutions, and high-performance capacitors and RF products, announced the QAS Series, a new line of RC-type Arc Suppressor/Snubber components that extend the operating life of electronic and electro-mechanical devices.

Knowles' Cornell Dubilier brand QAS Series devices provide single-device RC networks in two-lead radial packages. QAS networks extend the operating life of electronic and electro-mechanical devices by reducing and/or eliminating electrical arcing at the point of electrical contact. Without a snubber circuit, arcing often leads to early failures in relays, switch contacts, and solid-state components such as SCRs and TRIACs.

When the contacts in an arc suppression circuit open, a voltage is applied across the capacitor instead of the relay contacts. This prevents arcing because the capacitor charges faster than the contacts open. When the contacts close, the inrush current from the charged capacitor and source can exceed the safe conductance of the contacts. The resistor in the network limits the inrush current significantly, reducing the arc produced at contact closure, and extends the service life of the contacts. In practical applications, for DC voltage, the RC network is typically connected across the relay contacts, and for AC voltage, it is connected across the load.

The QAS is also effective at reducing spark-generated EMI/RFI that can cause interference with the operation of a circuit.

Each device consists of metallized polyester capacitor RC network, coated with a flame-retardant epoxy. Having a single device containing an RC network has advantages for circuit designers rather than building discrete networks. The single device is more compact, pretested, and environmentally more robust. The QAS product line includes 24 devices with:

• Capacitance values of up to 1.0uF
• Resistor values up to 680 ohms,
• Rated voltage options up to 1600 Vdc/660 Vac, 60 Hz
• Operating temperature range –55 °C to +85 °C at full rated voltage.