Microculonometer as a meter of electric charges

Abstract

The most difficult problem in the laboratory practice of the educational process for the demonstration of electrostatics and electromagnetism is the measurement of electric charges on the surface of bodies and in the airspace of the environment. The fundamental property of electric charges is determined by their type, which are conditionally called positive and negative, they are attracted or repelled, have an electromagnetic interaction. Characterized by an elementary charge i.e. the smallest value of electric charge, regardless of type. The electric charge can take only a discrete value proportional to the smallest charge, which can only be expressed as an integer regardless of the type of charge. Depending on the surface on which they are located, they can have different concentrations, which can be described by linear, surface or bulk density. Electric charges are subject to the law of conservation of charges – the sum of charges in an isolated system is constant. Measurement of electric charges is complex, devices – galvanometers and electroscopes, which are used for this purpose, require certain conditions that are not always convenient to use, do not provide the necessary accuracy of measurement. Methods and devices using the circuitry of a microcoulometer for measuring electric charges in electrostatics and electromagnetism, which is built on a modern element base with the use of operational amplifiers and microcontrollers, are proposed.

Keywords

• learning process
• electric charge
• electrostatics
• electromagnetic interaction
• charge conservation law
• operational amplifier
• microcontroller