SU1334358A1 - Glass d amplifier - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to radio engineering and provides stabilization of the gain factor with a change in load resistance. Amplifier (V) contains a source of 1 input of an o-r signal, controlled by integrator 2, a generator of 3 clock pulses, a comparator 4, a two-stroke key stage 5, a feedback circuit 6, triggers 7 and 8, an inverter 9, an OR 10 element, When the load changes, the voltage at output Y also changes. This change through feedback circuit 6 is transmitted to the 1st input of the comparator 4, which leads to a change in the amplitude of the sawtooth voltage at this input. Therefore, the moment of comparison of the input signal with the voltage at the 1st input of the comparator 4 will change, therefore, the average value of the input voltage will also change, which will ensure the constant gain factor when the load resistance changes. 1 il. (Lp Yu from 00. 1X ate X Lb4

Description

The invention relates to radio engineering and can be used to control DC and AC motors. : - The purpose of the invention is to stabilize the Gain with a change in load resistance.

The drawing shows a structural electrical amplifier class D circuit,

Class D amplifier contains input source 1, controlled integrator 2, 3 clock pulse generator, comparator 4, push-pull key stage 5, feedback circuit 6, first and second triggers 7 and 8, -inverter 9, of the OR 10 element.

Class D amplifier works as follows.

In the initial state, the first and second triggers 7 and 8 are in the state O, which corresponds to a zero potential at the output of an amplifier of class D, In the initial state, the potential at the first input of the comparator 4 is zero.

When the input signal of a positive polarity is fed to the second input of the comparator 4, a positive potential is formed at the output of the comparator 4, which keeps the first trigger 7 in the O state. When a positive pulse is fed from the generator output, 3 clock pulses, Pulse 7 is set to state 1, is connected to the first output of the reverse circuit, and second trigger 8 of its state of communication is different. However, it does not change.

The high level signal from the output of the first trigger 7 is fed to the input of the push-pull key stage 5, and through the element OR 10 to the control input of the controlled integrator 2. The latter starts to charge from the output voltage of the push-pull key jg th stage 5 through the reverse circuit 6 connection. The constant time of the controlled integrator 2 is chosen such that at the maximum output signal

communication, t

that in order to stabilize the coefficient. This gain when changing the load resistance, the first and second triggers, the inverter and the IL element are introduced, the second output of the feedback circuit is connected to the first input of the compara- tor. The second input of the comparator is connected to the output of the input source, the output of the generator is connected to the output of the input source, the output of the class D amplifier is the voltage per per gg pa of the clock pulses connected to the first input of the comparator 4 reached (before the arrival of the next clock pulse) the maximum allowable value of the input voltage.

 When the voltages are equal at the first and second inputs of the comparator 4, a low potential is formed at the output, and a high potential at the output of the inverter 9, which through the second trigger

the first and second trigger inputs, the outputs of which are connected to the corresponding inputs of the push-pull key stage and, via the OR element, to the control input of the controlled integrator, while the second input of the second trigger through the inverter and the second input of the first trigger are connected to the comparator output.

The generator disarms the managed integrator 2 in a short period of time.

Thus, at the output of a class D amplifier, a positive square pulse is formed, the duration of which is proportional to the level of the input signal.

When a negative polarity input signal is applied to the second input of the comparator 4, a negative square rectangular pulse, the duration of which is proportional to the level of the input signal, is formed in a similar way at the output of a class D amplifier.

When the load changes, the voltage at the output of the class D amplifier also changes. This change through the feedback circuit 6 is transmitted to the first input of the comparator 4, which leads to a change in the amplitude of the sawtooth voltage at the input of the comparator 4 changes with, therefore, changes and the average (for the period of the clock 5 pulses) value of the output voltage, which ensures the constant gain when the load resistance changes.

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Claims (1)

Invention Formula Class D amplifier containing input source, controlled integrator, clock generator, comparator, push pull a key stage whose output is connected to the first output of the feedback circuit is different. by that communication, t that in order to stabilize the coefficient. This gain when changing the load resistance, the first and second triggers, the inverter and the IL element are introduced, the second output of the feedback circuit is connected to the first input of the comparator, which through a controlled integrator is connected to the common bus, the second input of the comparator is connected to output of the input source, the output of the generator is connected to the output of the input source, the output of the generator the first and second trigger inputs, the outputs of which are connected to the corresponding inputs of the push-pull key stage and, via the OR element, to the control input of the controlled integrator, while the second input of the second trigger through the inverter and the second input of the first trigger are connected to the comparator output.