JPS6125309A - Level stabilizing circuit - Google Patents

Abstract

PURPOSE:To stabilize a sufficient level with a simple circuit by providing a logical circuit as a level stabilizing element, a BPF rectifying a rectangular wave into a sinusoidal wave and a control circuit generating a control voltage required to stabilize an output voltage. CONSTITUTION:A sinusoidal wave signal inputted to an input terminal 1 becomes a rectangular wave by the logical circuit 2. The rectangular wave is shaped into a sinusoidal wave by a BPF3 and the result is fed to an output terminal 4. Thus, the control circuit 5 rectifying an output voltage in order to obtain a DC control voltage required to stabilize an output voltage at the output terminal 4 and comparing the rectified voltage with a reference voltage of the stabilized DC voltage is provided. Then the rectified and compared DC control voltage obtained by the control circuit 5 is impressed to an input terminal 1 as a threshold voltage of the logical circuit 2. Thus, the sufficient stabilization of the level is attained with a simple circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a level stabilizing circuit for a carrier wave supply circuit used in a carrier device.

[Conventional technology]

Conventionally, this type of level stabilization circuit has a configuration as shown in Figure 2, in which a sine wave signal input to the input terminal (1) is amplified to a large amplitude voltage by a high amplification amplifier (6). Then, the level is stabilized by compression through a limiter circuit (7) using a diode or the like, and the configuration uses a band P waveform generator (3) that shapes the waveform of the circuit output into a sine wave. , aimed at stabilizing the level. For this reason, the configuration of the amplifier (6) described above requires performance of high amplification and high output power, which increases the number of parts used, uses high-priced parts, increases size, and increases power consumption. The problem was the amount of heat generated, and the reliability was also reduced.

[Purpose of the invention]

An object of the present invention is to make it possible to achieve a sufficient level of stability with a simple circuit configuration without using the circuit configuration having the above-mentioned drawbacks, and to improve various drawbacks in the conventional technology. .

[Structure of the invention]

The present invention provides a carrier wave supply circuit that includes a logic circuit as a level stabilizing element that inputs a sine wave, and converts a square wave output from the logic circuit into a sine wave! lk-shaped bandpass filter, and a control circuit that compares the rectified voltage obtained by rectifying the output voltage from the bandpass filter with a reference voltage and outputs a control voltage. The level stabilizing circuit is characterized in that a control voltage is applied to the input of the logic circuit to stabilize the output level of the carrier wave.

[Principle and operation of the invention]

The present invention injects a sine wave as an input signal into the input terminal of a commonly used logic circuit (for example, a Nant gate) and obtains a square wave as the output of the circuit. Next, the square wave 't-band f wave generator performs waveform shaping on the sine wave to obtain the required carrier wave output voltage. Here, in order to obtain the DC control voltage necessary to stabilize the output voltage, the output voltage is rectified, and this rectified voltage is compared with a reference voltage consisting of the stabilized DC voltage. First, a rectified and compared DC control voltage obtained by the control circuit is applied to an input terminal to be used as a threshold voltage of the logic circuit. Here, by configuring the logic circuit so that it is directly proportional to the increase/decrease between the sine wave voltage that is the input signal and the threshold voltage, the output of the logic circuit is The duty factor of a certain square wave increases or decreases, and the sine wave component included in the square wave increases or decreases.

[Explanation of Examples]

One embodiment of the present invention will be explained with reference to the block diagram shown in FIG.

In FIG. 1, (1) is an input terminal, (2) is a general logic circuit (for example, a Nant gate), (3) is a bandpass filter, (4) is an output terminal, (5) is a control circuit, (8) is a rectifier circuit, (9) is a reference voltage generation circuit, and (10) is a comparison circuit.

Control characteristics for level stabilization using the circuit configuration shown in FIG. 1 will be explained.

The sine wave signal input to the input terminal (1) is sent to the logic circuit (2).
) is entered. Since a threshold voltage determined by the DC control voltage from the control circuit 6) is applied to the input of the logic circuit (2), the output of the logic circuit (2) is a sine wave whose input exceeds the threshold voltage. This will generate a square wave with a time width proportional to the magnitude of the voltage.

Next, this square wave is shaped into a sine wave by a bandpass filter (3) and reaches an output terminal (4).

At the same time, the output signal at the output terminal (4) is rectified and the rectified voltage is compared with a reference voltage consisting of a stabilized DC voltage, and is applied to the control circuit (5).
As the output of step 5), a DC control voltage is generated which becomes the threshold voltage of the logic circuit (2). In addition, the control circuit (
5) is composed of a rectifier circuit (8), a reference voltage generation circuit (9), a comparison circuit (10), and K.

Here, the operational relationship of each part will be described. Since the configuration is such that the increase/decrease in the sine wave voltage that is the input signal is directly proportional to the increase/decrease in the threshold voltage, the change in the duty factor of the square wave that is the output of the logic circuit (2) is proportional to the sine wave that is the input signal. It will be inversely proportional to the increase or decrease in voltage. Since the increase/decrease in the duty factor of the square wave is inversely proportional to the increase/decrease in the sine wave component included therein, the output level can be stabilized by each of the above-mentioned relationships.

〔Effect of the invention〕

As described above (according to the present invention), it is possible to realize level stabilization with a simple circuit configuration without using an amplifier configuration having drawbacks, and to improve the disadvantages associated with the conventional amplifier configuration. There is an effect that can be done.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a level stabilizing circuit according to the present invention, and FIG. 2 is a block diagram showing a conventional level stabilizing circuit. DESCRIPTION OF SYMBOLS 1... Input terminal, 2... Logic circuit, 3... Bandpass filter, 4... Output terminal, 5... Control circuit, 8...
... Rectifier circuit, 9... Reference voltage generation circuit, 10...
・Comparison circuit.

Claims (1)

[Claims] In the carrier wave supply circuit, a logic circuit as a level stabilizing element that inputs a sine wave, a bandpass filter that shapes the square wave output from the logic circuit into a sine wave, and an output voltage from the bandpass filter. and a control circuit that compares the rectified voltage obtained by rectifying the voltage with a reference voltage and outputs a control voltage, and applies the control voltage of the control circuit to the input of the logic circuit to adjust the output level of the carrier wave. A level stabilizing circuit characterized by stabilizing the level.