Sapphire trimmer cap is non-magnetic for MRI use

May 12, 2014 // By Graham Prophet
Voltronics has added to its range of non-magnetic trimmer (variable) capacitors; the company claims to have the widest range of such products for Magnetic Resonance Imaging available. V9000 series is the company’s smallest, high voltage trimmer capacitor.

The V9000 Sapphire trimmer capacitor is sub-miniature at just 0.64 in. (16.3 mm) (at minimum capacitance) in length, but offers the highest working voltage rating (2 kV) for its size - whilst delivering a capacitance range of 1 to 12pF. Sapphire is ideal for precision trimmer capacitors as its dielectric constant is extremely stable, measuring below 0.0003 up to 10 GHz, and is chemically inert; totally moisture resistant and mechanically strong.

These trimmers have a high Q (3000 min at 100 MHz); DC working voltage of 2000V and DC withstand of 3000V. They are also compatible with SAC 305 reflow processing.

The V9000 Series is designed for the MRI industry where its size, power, capacitance range and affordability make it the preferred choice for the next generation of coils. Due to the severe non-magnetism requirements this industry requires it employs only materials that exhibit no measurable magnetism - commercial brass and plating materials are not acceptable. Strict traceability and testing regimes ensure this essential parameter.

Knowles Capacitors embraces the former brands of Dielectric Laboratories (DLI), Novacap, Syfer Technology and Voltronics;