CN201418039Y

CN201418039Y - AC dump sampling circuit

Info

Publication number: CN201418039Y
Application number: CN2009201318105U
Authority: CN
Inventors: 沈楚春
Original assignee: Shenzhen Megmeet Electrical Technology Co Ltd
Current assignee: Shenzhen Megmeet Electrical Co Ltd
Priority date: 2009-05-13
Filing date: 2009-05-13
Publication date: 2010-03-03
Anticipated expiration: 2019-05-13

Abstract

The utility model discloses an AC (alternating current) dump sampling circuit, which includes a transformer, as well as a rectifier filter circuit, a voltage comparison circuit and a signal output circuit connected sequentially; and a secondary winding of the transformer is connected with the rectifier filter circuit. The utility model can accurately process commercial power dump sampling signalsand greatly reduce the cost of the sampling circuit by rectifying and filtering sampling signals of the secondary winding separated from the transformer, and performing the level translation through atriode switch.

Description

A kind of interchange power down sample circuit

Technical field

The utility model relates to the circuit engineering field, relates in particular to a kind of interchange power down sample circuit.

Background technology

To be civil power by AC side rectification step-down filtering, by the light lotus root isolate present widely used interchange power down Sampling techniques circuit is transferred to the sample detecting circuit that secondary carries out, as shown in Figure 1 and Figure 2, its circuit basic principle, by step-down and reference voltage after the electric main rectification are compared, make the conversion of comparator output level, by the light lotus root Signal Spacing is transferred to secondary for MICROCOMPUTER PROCESSING again.Its effect is to make LCD LCD TV or PC etc. need power down process equipment to carry out power down process.This interchange power down process signal circuit is by the high pressure drop volt circuit, and light lotus root isolation level change-over circuit is formed, and cost is higher.

The utility model content

The technical problems to be solved in the utility model provides a kind of interchange power down sample circuit.

For solving the problems of the technologies described above, the purpose of this utility model is achieved through the following technical solutions.

A kind of interchange power down sample circuit comprises: transformer, the current rectifying and wave filtering circuit, voltage comparator circuit and the signal output apparatus that link to each other successively; Described transformer secondary winding links to each other with described current rectifying and wave filtering circuit.

Wherein, described current rectifying and wave filtering circuit comprises that secondary one end of diode and first electric capacity, transformer links to each other with the anode of diode, and the negative electrode of diode links to each other with the secondary other end of transformer by first electric capacity.

Wherein, described voltage comparator circuit comprises first resistance and second resistance, and is in parallel with first electric capacity after first resistance is connected with second resistance.

Wherein, described signal output apparatus comprises the 3rd resistance, the 5th resistance, first triode and second triode, first resistance links to each other by the base stage of the 3rd resistance with first triode with the mid point of second resistance, the collector electrode of first triode links to each other with the base stage of second triode by the 5th resistance, and the emitting stage of first triode all links to each other with the secondary other end of transformer with the emitter of second triode.

Wherein, also comprise second electric capacity, described second electric capacity is connected in parallel between the base stage and emitter of second triode.

Wherein, also comprise the 6th resistance, the collector electrode of described second triode links to each other with the base stage of first triode by the 6th resistance.

The beneficial effects of the utility model are as follows:

The utility model passes through the secondary winding rectifying and wave-filtering sampled signal from transformer isolation, and makes level conversion by triode switch, thereby can accurately handle civil power power down sampled signal, reduces the sample circuit cost greatly.

Description of drawings

Fig. 1 is existing a kind of interchange power down sample circuit figure;

Fig. 2 is the existing another kind of power down sample circuit figure that exchanges;

Fig. 3 is the utility model schematic block circuit diagram;

Fig. 4 exchanges power down sample circuit figure for the utility model.

Embodiment

For ease of the utility model is further understood, now reach specific embodiment in conjunction with the accompanying drawings the utility model is described in detail.

Basic principle of the present utility model is that step-down and voltage ratio produce low-level output signal for the MICROCOMPUTER PROCESSING power-off signal, as shown in Figure 3 again by existing transformer secondary winding T process rectifying and wave-filtering.

See also shown in Figure 4ly, comprising: transformer T, diode D1, first capacitor C 1, second capacitor C 2, the 3rd capacitor C 3, the first triode Q1, the second triode Q2, first resistance R 1, second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7, the 8th resistance R 8; Secondary one end of transformer T links to each other with the anode of diode D1, and the negative electrode of diode D1 links to each other with the secondary other end of transformer T by first capacitor C 1; It is in parallel after first resistance R 1 is connected with second resistance R 2 with first capacitor C 1, first resistance R 1 links to each other by the base stage of resistance R 3 with the first triode Q1 with the mid point of second resistance R 2, the collector electrode of the first triode Q1 links to each other with the base stage of the second triode Q2 by the 5th resistance R 5, the collector electrode of the second triode Q2 links to each other with the base stage of the first triode Q1 by the 6th resistance R 6, the emitting stage of the first triode Q1 all links to each other with the secondary other end of transformer T with the emitter of the second triode Q2, second capacitor C 2 is connected in parallel between the base stage and emitter of the second triode Q2, the 3rd capacitor C 3 is connected in parallel between the collector electrode and emitter of the second triode Q2, the 7th resistance R 7 and the 8th resistance R 8 backs in parallel one termination 5V voltage, the other end links to each other with the collector electrode of the second triode Q2, the 4th resistance R 4 one termination 5V voltages, the other end links to each other with the collector electrode of the first triode Q1.

Fig. 4 circuit working principle:

When line voltage reduced, transformer T secondary winding voltage reduced, through producing voltage U 1 after the D1 rectification C1 filtering, by detecting the U1 signal, ratio reflection line voltage power down value.When being low to moderate certain value, when promptly the B1 voltage that is divided to of R1, R2 was lower than 0.7V, Q1 was become by conducting and ends, and Q1 turn-offs, and the c1 point voltage becomes high level, drives the Q2 conducting by R5, and the output power-off signal becomes low level by high level.This signal is sent into microcomputer and is handled, and preserves the preceding information of power down and makes the needed information storage of free processing such as LCD TV or PC, and system is unlikely after civil power is sent a telegram here again makes mistakes.C2 is a filter circuit, prevents that Q2 is by misoperation when becoming conducting.R6 eliminates Q1, Q2 switch upset back misoperation for introducing regenerative circuit.

More than a kind of interchange power down sample circuit provided by the utility model is described in detail, used specific case herein principle of the present utility model and execution mode are set forth, the explanation of above embodiment just is used for helping to understand core concept of the present utility model; Simultaneously, for one of ordinary skill in the art, according to thought of the present utility model, the part that all can change in specific embodiments and applications, in sum, this description should not be construed as restriction of the present utility model.

Claims

1, a kind of interchange power down sample circuit is characterized in that, comprising: transformer, the current rectifying and wave filtering circuit, voltage comparator circuit and the signal output apparatus that link to each other successively; Described transformer secondary winding links to each other with described current rectifying and wave filtering circuit.

2, interchange power down sample circuit according to claim 1, it is characterized in that, described current rectifying and wave filtering circuit comprises that secondary one end of diode and first electric capacity, transformer links to each other with the anode of diode, and the negative electrode of diode links to each other with the secondary other end of transformer by first electric capacity.

3, interchange power down sample circuit according to claim 2 is characterized in that, described voltage comparator circuit comprises first resistance and second resistance, and is in parallel with first electric capacity after first resistance is connected with second resistance.

4, interchange power down sample circuit according to claim 3, it is characterized in that, described signal output apparatus comprises the 3rd resistance, the 5th resistance, first triode and second triode, first resistance links to each other by the base stage of the 3rd resistance with first triode with the mid point of second resistance, the collector electrode of first triode links to each other with the base stage of second triode by the 5th resistance, and the emitting stage of first triode all links to each other with the secondary other end of transformer with the emitter of second triode.

5, according to each described interchange power down sample circuit of claim 1 to 4, it is characterized in that also comprise second electric capacity, described second electric capacity is connected in parallel between the base stage and emitter of second triode.

6, interchange power down sample circuit according to claim 5 is characterized in that, also comprises the 6th resistance, and the collector electrode of described second triode links to each other with the base stage of first triode by the 6th resistance.