Unusual types of gramophone records Hi-Fi was a system of proprietary records and players designed for use in automobiles, utilizing a slower play speed and high stylus pressure. With their origin stretching back to the dawn of recorded sound at the turn of the 20th century, flexible recording media have been made from a variety of materials including foil, paper, and–in the 1950s–thin flexible vinyl known as flexi discs. Thin, flexible paper-based records were briefly popularized in the 1930s by Hit of the Week Records and Durium Records. "Melody Cards" were popular in the late 1950s. They took the form of an oversized rectangular postcard
Polymer capacitor aluminum oxide and tantalum pentoxide have little impact on the specific capacity due to different safety margins in oxide layers. Polymer Ta-e-caps use an oxide layer thickness that corresponds to approximately four times the rated voltage, while the polymer Al-e-caps have about twice the rated voltage. Cylindrical polymer aluminum capacitors based on the technique of wound aluminum electrolytic capacitors with liquid electrolytes. They are available only with aluminum as anode material. They are intended for larger capacitance values compared to rectangular polymer capacitors. Due to their design, they may vary in height on a given surface mounting area so that