SU80953A1 - AC rectifier - Google Patents

Description

An object of the present invention is an AC rectifier that rectifies with non-linear elements to which an auxiliary AC voltage is applied. Straightening occurs only at a certain ratio of the frequencies of rectified and auxiliary voltages; The choice of this ratio depends on the current-voltage characteristic of the applied nonlinear element.

In various electrical circuits and devices, it is necessary to detect, isolate, or measure the voltage (or individual harmonics) of a well-defined frequency. Sometimes it is required to rectify the alternating voltage so that the magnitude and polarity of the resulting constant (rectified) voltage is a function of the rectified alternating voltage phase.

In a number of cases, it is desirable to have such elements or devices, the output voltage (or current) of which would be proportional to the square of the voltage (or current) at their input.

Such problems are proposed to be solved using a circuit with non-linear resistances such as tirith, to which a control (auxiliary) alternating voltage is applied.

The scheme of the proposed rectifier is shown in the attached drawing. Here / and 2 are thyrite elements, 3 is a load conpoTHBj, shunted with capacitance C, 4 is a balancing transition transformer, 5 is a source of rectified non-temporal current, 6 is an auxiliary source of alternating voltage.

If a sinusoidal voltage Ui cos caii is applied to the clamps of the primary winding of the transformer 4, and a voltage is applied to the clamps of the /// - IV voltage (Uz tos (co2 / + a)), the rectification component of the current in the load, occurs only at certain ratios of frequencies and (02. Capacitor C, bypassing the load, serves to smooth the ripple of the load current. In the simplest case, when the tirite current-voltage characteristic is cubic, straightening occurs at / g and 2.

Thus, if a fixed auxiliary voltage is applied to the / - // terminals (7, we built;; the frequency coi of which is two times less than the voltage frequency t / 2, then the magnitude of the rectified current will be directly proportional to the amplitude of the voltage f / 2 and depends on the phase of this voltage, while the linear dependence of the constant component of the load current on the amplitude of the rectified voltage t / j is preserved for arbitrarily small values of the latter.

If the frequency of the fixed auxiliary voltage is twice the frequency of the rectified voltage t / s, then the load current will be proportional to the square of the rectified voltage U.

For any other ratios of frequencies oi / coa, different from / 2 and 2, rectification does not occur. This is true if the volt-ampere characteristic of tyrITON is cubic.

The characteristics of real tirits may be expressed by polynomials of a higher order than the third.

The higher the order of the polynomial expressing the current-voltage characteristic of tirithas, the greater the number of frequency ratios (. At which straightening occurs. For example, for tirites characterized by a polynomial of the same order, straightening occurs at the following frequencies: / 4 ,%; 2; / l / g and / i, etc.

The above properties of the proposed rectifier circuit can be achieved using a single half-period circuit containing only one nonlinear resistance (tirite).

Subject invention

An AC rectifier with non-linear elements, characterized in that an auxiliary AC voltage is applied to non-linear elements and therefore the rectification occurs only at a certain ratio of the auxiliary and rectified voltage, and the magnitude and polarity of the cf voltage depends on rectified phase voltage.