PIEZOELECTRIC CHARGER CD V-751X.
Abstract
The design, development and fabrication of a ra diological dosimeter charger, which uses piezoe lectric ceramic crystals to generate the electri cal energy and a lens system for external ambient light only, is described. This charger has been developed as a possible replacement for the tran sistorized charger, but requires no batteries; therefore, it has long shelf life. The effects of static stress on the piezoelectric properties of different ceramic materials were studied and asic formulas derived. Studies showed that the charge generated by the application of force to the piezoelectric material was directly propor tional to force and to the material constant but was not dependent on the size. The material ''constants'' varied with stress, however, par ticularly at high stress values, so the size and shape affects the charge output indirectly. In the final design, force was applied to the cera mic crystals by a spring loaded screw arrangement. Two lead-zirconate-titanate ceramic crystals were arranged in tandem mechanically, but in parallel electrically. A swamping capacitor provided fine adjustment of the low range dosimeter; a ne on lamp was used to protect the dosimeter against over-voltage. A special shorting switch was de signed and incorporated to prevent reversal of polarity. An optical system in the charger transmitted light from an external source to il luminate the dosimeter scale and fiber. The charger is capable of using either natural sun light or concentrated sources of light. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 09, 1963
- Accession Number
- AD0418674
Entities
People
- John Stirnkorb
- R. Lehman