Calculator This led the way to the first credit-card-sized calculators, such as the Casio "Mini Card LC-78" of 1978, which could run for months of normal use on button cells. There were also improvements to the electronics inside the calculators. All of the logic functions of a calculator had been squeezed into the first "calculator on a chip" integrated circuits (ICs) in 1971, but this was leading edge technology of the time and yields were low and costs were high. Many calculators continued to use two or more ICs, especially the scientific and the programmable ones, into the late 1970s. The
Integrated Electronics Piezo-Electric Integrated Electronics Piezo-Electric The abbreviation IEPE stands for Integrated Electronics Piezo-Electric. It characterises a technical standard for piezoelectric sensors which contain built-in impedance conversion electronics. IEPE sensors are used to measure acceleration, force or pressure. Measurement microphones also apply the IEPE standard. Other proprietary names for the same principle are ICP, CCLD, IsoTron or DeltaTron. The electronics of the IEPE sensor (typically implemented as FET circuit) converts the high impedance signal of the piezoelectric material into a voltage signal with a low impedance of typically 100 Ω. A low impedance signal is advantageous because it can be transmitted across long