The transformer transformation ratio or transformer turns ratio (K) is the quotient value obtained by dividing the number of turns of the primary winding (N1) and the number of turns of the secondary winding (N2). Then K = N1/N2

In a parallel RC circuit:

– The value of the voltage is the same on the capacitor and resistor.

– The value of the current delivered by the voltage source, is divided between the resistor and capacitor.

The series RC circuit. In a series RC circuit,

The current through the resistor and the capacitor is the same. The voltage VS is equal to the phasor addition of the voltage drop across the resistor (Vr) and the voltage drop across the capacitor (Vc).

Capacitor and Alternating Current (AC). Alternating current in capacitive circuits.

Unlike the behavior of a capacitor in DC, the alternating current (AC) passes more easily through a capacitor.

Power in AC circuits.

Electric power. Electrical power on a circuit with reactive load (reactance).

How to obtain the current in a circuit having resistance and reactance.

Power Factor Definition

Power factor is the ratio between the energy that is converted into work and the electrical energy consumed in a circuit or device

The Crystal Oscillators A quartz crystal has a property called: piezoelectric effect. This effect causes, by applying a mechanical pressure on the surface of the crystal, that a voltage is developed on the opposite sides. In a similar manner, a voltage applied on the faces of the crystal produces a mechanical distortion on their surface. An AC voltage causes mechanical […]

LC oscillator: Inductance – Capacitance Oscillator A simple oscillator can be built with an amplifier stage and an inductive-capacitive network (LC) to provide an offset of -180° The oscillation frequency can be freely adjusted or tuned on a range of frequencies from 100kHz to a few hundred MHz by changing only the value of C or L. These LC […]

The Phase Shift Oscillator The phase shift oscillator, whose basic structure is described in the picture 1.a  has a a negative gain amplifier (-K) and a feedback network consisting of a third order RC section in cascade. The oscillation condition requires that the feedback network produce a phase shift of 180° to be consistent with the negative gain amplifier which […]

Wien-bridge Oscillator using Op-Amp The Wien-bridge oscillator, as shown on the basic outline of the diagram below, consists of an Operational Amplifier (OA) in a non-inverting configuration with gain 1+R2/R1 and a RC feedback network with the following transfer function: Where: Combining the first and the second equation we get: The loop gain (BA) is: The Barkhausen criterion […]

Nonlinear Amplitude Control of a Sinusoidal Oscillator In any practical oscillator, the loop gain (ßA) must be slightly greater than unity to prevent that the tolerance parameters of components, aging, temperature effects, etc., make that ßA<1 and the circuit not meet one of the oscillation conditions specified in the equation: In which case the circuit will […]

Basic structure of the sinusoidal oscillator

The sinusoidal oscillator basic structure consists of an amplifier (A) and a selective frequency network (ß) connected in a positive feedback loop