DC Electric circuits

Alternating current AC is the carrier of information and also a common way of transporting electrical energy. When calculations are done in AC circuits, understanding of complex voltages, complex current and impedances is essential. Besides working with (harmonic) AC sources, the complex plane forms the base for presentation of calculated state variables (phasors). Impedances like (real) resistors, and the (imaginary) reactive impedances such as capacitors and inductors are basic circuit components. All law, theorems and procedures we learned in DC circuits also apply to AC circuits. The fundamental waveform is the sine wave, which is the building block of all other waveforms, the basic of the signal theory behind this is discussed and RMS and average values of some basic signals calculated. With passive components filters are made, part of the course consists of basic filter theory (1st order LPF, HPF and 2nd order LPF, HPF, BPF). Terms like transfer function, Bode diagram, angular frequency, roll -off frequency, phase, time constant, resonance, bandwidth and quality factor are used to understand these circuits. In practical OPAMP circuits capacitors are important. The frequency behaviour of inverting and noninverting amplifiers is discussed and the role of coupling- and de-coupling capacitors.