Electrode electrode. In a vacuum tube or a semiconductor having polarity (diodes, electrolytic capacitors) the anode is the positive (+) electrode and the cathode the negative (−). The electrons enter the device through the cathode and exit the device through the anode. Many devices have other electrodes to control operation, e.g., base, gate, control grid. In a three-electrode cell, a counter electrode, also called an auxiliary electrode, is used only to make a connection to the electrolyte so that a current can be applied to the working electrode. The counter electrode is usually made of an inert material, such as a
Electrolytic capacitor and phase at a particular frequency. In data sheets of electrolytic capacitors only the impedance magnitude "|Z|" is specified, and simply written as ""Z"." Regarding the IEC/EN 60384-1 standard, the impedance values of electrolytic capacitors are measured and specified at 10 kHz or 100 kHz depending on the capacitance and voltage of the capacitor. Besides measuring, the impedance can be calculated using the idealized components of a capacitor's series-equivalent circuit, including an ideal capacitor "C", a resistor "ESR", and an inductance "ESL". In this case the impedance at the angular frequency "ω" is given by the geometric (complex) addition of