Sprava za merenje jačine električne struje ili otpora (lat.-grč.)
1. A 3-terminal resistor with an adjustable center terminal; used to adjust voltages in radios and tv sets; SYN. pot.
2. An instrument for measuring direct current electromotive forces.
Instrument for measuring electromotive forces
Instrument measuring electromotive force or potential difference by comparison with a known voltage.
In physics, an electrical resistor that can be divided so as to compare, measure, or control voltages. In radio circuits, any rotary variable resistance (such as volume control) is referred to as a potentiometer.
A simple type of potentiometer consists of a length of uniform resistance wire (about 1 m/3 ft long) carrying a constant current provided by a battery connected across the ends of the wire. The source of potential difference (voltage) to be measured is connected (to oppose the cell) between one end of the wire, through a galvanometer (instrument for measuring small currents), to a contact free to slide along the wire. The sliding contact is moved until the galvanometer shows no deflection. The ratio of the length of potentiometer wire in the galvanometer circuit to the total length of wire is then equal to the ratio of the unknown potential difference to that of the battery.
A circuit element that can be adjusted to provide varying amounts of resistance. The twist-knob and slider-type volume controls on many radios and television sets are potentiometers. Also called: pot.