As the symbol hints the varistor is a voltage dependent resistor. Primarily it is used for taking care of voltage transients of different shapes. Unlike thermistors it has no practical time delay of its function. R 5.3.1 Function and design Just as thermistors the varistor is fabricated from a compressed and sintered powder compound that consists of silicon carbide (SiC) or zinc oxide (ZnO)....

by Paul Svasta, Ciprian Ionescu, Alexandru Vasile, Cristina Marghescu, Bogdan Mihailescu, Andrei Drumea, Norocel Codreanu University “Politehnica” of Bucharest, Romania, Center of Technological Electronics and Interconnection Techniques, UPB-CETTI presented by P.Svasta at the 2nd PCNS 10-13th September 2019, Bucharest, Romania as Keynote 4 presentation Abstract At the end of the 70s, an electronic passive components manufacturer had used as motto of its products: ”Today...

by Ron Demcko AVX Corporation Fellow, USA presented by R.Demcko at the 2nd PCNS 10-13th September 2019, Bucharest, Romania as Keynote 1 and rated by PCNS attendees as the best Keynote presentation Abstract In the past, system power budgets and data/operating speeds were wide and slow respectively. This allowed passive component selection and consideration to occur at the end of the design cycle. Today in...

R 5.1 NTC THERMISTORS In this section we shall describe some non-linear resistor styles, meaning that they don’t follow Ohm’s law. Simplified, the resistor material consists of doped granule compounds containing various oxides that by means of binders have been pressed to a desired shape and then sintered. The terminals either are inserted into the resistor body or soldered to metallized surfaces. There are...

The need for small, adjustable resistors created trim potentiometers. They lack the potentiometer shaft and are operated through an adjustment screw or a rotor. The setting needs to be maintained during handling and environmental influence. Thus, the contact pressure of the wiper is high. The setting stability is specified as a voltage change expressed in percent of input voltage. The first trimming potentiometers had...