Improvements in or relating to piezo-electric elements and electric circuits using such elements

Abstract

Abstract 824,786. Heating resistor coatings. GENERAL ELECTRIC CO. Ltd. Nov. 6, 1957 [Nov. 16, 1956], No. 35128/56. Class 39(3) [Also. in Groups XIII, XXXV and XL(b)] A metal electrode on one surface of a piezo-electric crystal forms an electric heater 4 to maintain the crystal at a constant temperature. The electrode or heater 4 is of silver or gold, is 0.5 microns thick and may be produced by a printed circuit technique e.g. by masking the crystal surface and then sputtering or evaporating silver in a vacuum. The silver may be sprayed through a mask, or parts of a continuous silver surface are removed by acid etching, electro etching or spark erosion. The crystal is mounted in a metal or glass chamber which may have double walls, the whole being evacuated. Any glass walls may be silvered. D.C. is supplied to terminals 6, 7, the heater being one arm of a bridge circuit to maintain constant temperature.

Inventors

• 👤 Arthur Edward Harrold

Bibliographic Details