CN101738526B - Direct current output voltage test circuit for power factor correction control circuit - Google Patents

Abstract

The invention discloses a DC output voltage detection circuit used in a power factor correction control circuit. The power factor correction control circuit includes a central processing unit. The invention includes a voltage transformer T, and the output of the voltage transformer T A diode D1, a second resistor R2, a comparator D, a fifth resistor R5, and an optocoupler are sequentially connected to the loop, and an output terminal of the optocoupler is connected to a sixth resistor R6 and a seventh resistor R7, and the seventh resistor R7 passes through a The second capacitor C2 is connected to the other output terminal of the optocoupler and grounded, and one end of the second capacitor C2 connected to the seventh resistor R7 is connected to the central processing unit, and also includes a first resistor R1, a first capacitor C1, The third resistor R3 and the fourth resistor R4. The DC output voltage detection circuit used in the partial chopper type power factor correction control circuit of the present invention has the advantage of simple structure and can detect the DC output voltage value.

Description

DC output voltage detection circuit for power factor correction control circuit

technical field

The invention relates to a voltage detection circuit, in particular to a direct current output voltage detection circuit used in a partial chopping type power factor correction control circuit.

technical background

In recent years, with the development of electronic technology, more and more attention has been paid to the pollution of power grid by current harmonics and reactive power that may be generated by various electronic equipment and household appliances. The existence of harmonics not only greatly reduces the input The power factor of the circuit, and can cause pollution to the public power system, causing circuit failure. At present, in order to effectively improve the power factor, reduce the requirements for components and reduce the loss of effective components, the chopping method of partial chopping in each voltage cycle can be used for control. This part of the chopping type power factor correction control circuit must be A simple DC output voltage detection circuit is adopted, therefore, the applicant of the present application is devoted to researching a simple DC output voltage detection circuit suitable for a partial chopping type power factor correction control circuit.

Contents of the invention

The object of the present invention is to provide a DC output voltage detection circuit for partial chopper type power factor correction control circuit, which has the advantage of simple structure and can detect the DC output voltage value.

The technical solution to achieve the above object is: a DC output voltage detection circuit for a power factor correction control circuit, the power factor correction control circuit includes a central processing unit, wherein it includes a voltage transformer T, the voltage The output circuit of the transformer T is sequentially connected with a diode D1, a second resistor R2, a comparator D, a fifth resistor R5, and an optocoupler, and one output end of the optocoupler is connected with a sixth resistor R6 and a seventh resistor R7. The seven resistors R7 are connected to the other output terminal of the optocoupler through a second capacitor C2 and grounded, and the end of the second capacitor C2 connected to the seventh resistor R7 is connected to the central processing unit, and also includes a first resistor R1, The first capacitor C1, the third resistor R3 and the fourth resistor R4, wherein:

One end of the first resistor R1 is connected to the output end of the diode D1, and the other end is connected to an output end of the voltage transformer T and grounded;

One end of the first capacitor C1 is connected to the comparator D, and the other end is connected to an output end of the voltage transformer T;

One end of the fourth resistor R4 is connected to the output end of the comparator D, and the other end is connected to an output end of the voltage transformer T;

One end of the third resistor R3 is connected to the output end of the comparator D, and the other end is connected to a power supply.

In the aforementioned DC output voltage detection circuit for a power factor correction control circuit, the sixth resistor R6 is connected to a 5V power supply, and the third resistor R3 is connected to a 15V power supply.

The beneficial effects of the present invention are: the present invention compares the extracted AC voltage half-wave signal with the divided voltage signal of the output DC voltage through a comparator, and processes it through the central processing unit to obtain the AC and DC voltage values to be measured , the circuit has the advantages of simple structure and strong practicability.

Description of drawings

Fig. 1 is a circuit diagram of the DC output voltage detection circuit of the present invention.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing.

Please refer to Fig. 1, a kind of AC input voltage amplitude detection circuit used for power factor correction control circuit of the present invention is shown in the figure, the power factor correction control circuit includes a central processing unit 2, and the present invention includes a voltage transformer T, the output circuit of the voltage transformer T is sequentially connected with a diode D1, a second resistor R2, a comparator D, a fifth resistor R5 and an optocoupler 1, and an output terminal of the optocoupler 1 is connected with a sixth resistor R6 and The seventh resistor R7, the seventh resistor R7 is connected to the other output terminal of the optocoupler 1 through a second capacitor C2 and grounded, the end of the second capacitor C2 connected to the seventh resistor R7 is connected to the central processing unit 2, and includes The first resistor R1, the first capacitor C1, the third resistor R3 and the fourth resistor R4, wherein:

One end of the first resistor R1 is connected to the output end of the diode D1, and the other end is connected to an output end of the voltage transformer T and grounded;

One end of the first capacitor C1 is connected to the comparator D, and the other end is connected to an output end of the voltage transformer T;

One end of the fourth resistor R4 is connected to the output end of the comparator D, and the other end is connected to an output end of the voltage transformer T;

One end of the third resistor R3 is connected to the output end of the comparator D, and the other end is connected to a 15V power supply;

The sixth resistor R6 is connected to a 5V power supply.

The working principle of the circuit is: the voltage transformer T takes out the half-wave signal of the AC voltage and compares it with the divided voltage signal Uo of the output DC voltage. When the instantaneous value of the AC voltage is slightly greater than the value of the DC output voltage, a falling edge signal is output to the central processing unit. After the central processing unit 2 captures the signal, it records the current time of the synchronous timer, and at the same time samples the instantaneous voltage value of the AC input voltage output link, and then converts the value accordingly to obtain the required measurement AC and DC voltage values.

It should be noted that: the above is only used to illustrate and not limit the technical solution of the present invention. Although the present invention has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that the present invention can still be modified or equivalently replaced. Any modification or partial replacement without departing from the spirit and scope of the present invention shall fall within the scope of the claims of the present invention.

Claims (2)

1. VD testing circuit that is used for power factor correction control circuit; Described power factor correction control circuit includes a central processing unit; It is characterized in that; This VD testing circuit comprises a voltage transformer (VT) T, is connected with diode D1, second resistance R 2, comparer D, the 5th resistance R 5 and optocoupler on the output loop of this voltage transformer (VT) T in turn, is connected with the 6th resistance R 6 and the 7th resistance R 7 on the output terminal of optocoupler; The 7th resistance R 7 links to each other with another output terminal of optocoupler and ground connection through one second capacitor C 2; An end that links to each other with the 7th resistance R 7 of second capacitor C 2 links to each other with described central processing unit, and this VD testing circuit also comprises first resistance R 1, first capacitor C 1, the 3rd resistance R 3 and the 4th resistance R 4, wherein:

One end of described first resistance R 1 links to each other with the output terminal of described diode D1, and the other end links to each other with the output terminal of described voltage transformer (VT) T and ground connection;

One end of described first capacitor C 1 links to each other with described comparer D, and the other end links to each other with the output terminal of described voltage transformer (VT) T;

One end of described the 4th resistance R 4 links to each other with the output terminal of described comparer D, and the other end links to each other with the output terminal of described voltage transformer (VT) T;

One end of described the 3rd resistance R 3 links to each other another termination power with the output terminal of described comparer D.

2. the VD testing circuit that is used for power factor correction control circuit according to claim 1 is characterized in that, connects the power supply of 5V on described the 6th resistance R 6, connects the power supply of 15V on described the 3rd resistance R 3.

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