CN201145585Y

CN201145585Y - Voltage signal conditioning circuit

Info

Publication number: CN201145585Y
Application number: CNU2007200927376U
Authority: CN
Inventors: 范昆仑
Original assignee: Henan Suoling Electric Co Ltd
Current assignee: Henan Suoling Electric Co Ltd
Priority date: 2007-11-19
Filing date: 2007-11-19
Publication date: 2008-11-05
Anticipated expiration: 2017-11-19

Abstract

The utility model relates to a voltage signal conditioning circuit, which comprises a reference circuit, a passive low-pass filter circuit and a voltage follower circuit and also comprises an active two-stage low-frequency filter circuit, a fixed quantity compensating circuit and an amplitude limiting protection circuit, wherein, the fixed quantity compensating circuit and the active low-frequency filter circuit are used for 2.5 volt fixed quantity compensation and active low-frequency filtering, and the amplitude limiting protection circuit is used for amplitude limiting treatment of voltage signals between 0 and 5 volts. After adoption of the structure, the utility model provides the practical device, namely the voltage conditioning circuit with the functions of continuous tunableness between 0 and 2.4 volts, active filtering and so on aiming at collection of 50 Hz electrical quantity in an electric power system. The voltage signal conditioning circuit is characterized by simple debugging, low cost, stable performance, strong reliability and so on.

Description

The voltage signal modulate circuit

Technical field

The utility model relates to a kind of voltage signal modulate circuit.

Background technology

IC such as MCU, DSP is bringing into play important effect because computing velocity is fast, control function is strong, low in energy consumption, lower-price characteristic aspect the measurement in the mechanical floor of the integrated automation of transformation stations, control, the protection.And the measurement of this play electric parameters must be passed through mutual inductor (voltage, electric current), transducer (voltage, electric current), active filter etc. by voltage, the electric current of electric system, finally becomes the voltage signal that IC can discern.Such as, the built-in A/D of single-chip microcomputer can only discern 0～+ unipolar signal of 5V, promptly the sine voltage signal that above-mentioned link was handled must be raised 2.5V (this process abbreviates the polarity conditioning as), so that built-in A/D identification filters afterwards in program design.At present, there are problems such as element many (inconvenience debugging), price height in the voltage signal modulate circuit of using on the market, be badly in need of the collection of design, possess the utility unit of the voltage modulate circuit of functions such as raising 0～2.5V (adjustable continuously), active power filtering at 50HZ electric weight in the electric system.

The utility model content

The utility model purpose is to provide a kind of voltage signal modulate circuit.

To achieve these goals, the utility model adopts following technical scheme: the voltage signal modulate circuit, comprise reference circuit circuit, passive low-pass filter circuit, voltage follower circuit, this circuit also comprises the active low-frequency filter circuit of the two-stage that is connected between reference circuit circuit and the passive low-pass filter circuit, quantitative compensation circuit and limiter protection circuit, and voltage follower circuit is arranged between active low-frequency filter circuit of two-stage and the limiter protection circuit; Wherein quantitative compensation circuit and active low-frequency filter circuit are used for 2.5V quantitative compensation and active low frequency filtering; Limiter protection circuit is used for carrying out amplitude limiting processing to exporting 0～5V voltage signal.

Described limiter protection circuit comprises the clamp diode by the clamp diode of tie point and the+sensing noble potential that 5V links to each other and the sensing noble potential that links to each other with ground.

The active low-frequency filter circuit of the first order is used for the voltage quantitative compensation in the active low-frequency filter circuit of described two-stage, and DC component is output as-2.5V; The active low-frequency filter circuit in the second level comprises inverter circuit, and DC component is output as+2.5V.

After having adopted this structure, collection at 50HZ electric weight in the electric system, the utility unit that possesses the voltage modulate circuit of functions such as raising 0～2.5V (adjustable continuously), active power filtering, this device have characteristics such as debugging is simple, with low cost, stable performance, good reliability.

Description of drawings

Fig. 1 is the utility model circuit theory diagrams;

Fig. 2 is the concrete circuit diagram of implementing of the utility model.

Embodiment

Shown in the enforcement illustration of the schematic diagram of Fig. 1 and Fig. 2, the gain-adjusted of smooth linear: this circuit adopts the voltage input, the Ui circuit input end, the accurate adjustable potentiometer of w1 multi-turn, realize the gain-adjusted of smooth linear, U1 among the LM324 forms voltage follower, to guarantee that input resistance keeps constant in the gain-adjusted process.Reference circuit: VD 1, VD 2, LM336, W2, W3 and R8 form reference voltage circuit, and by regulating accurate adjustable potentiometer W2 of multi-turn and W3, the output that can make reference voltage is at 0～2.5V adjustable continuously (in conjunction with Fig. 2).

2.5V quantitative compensation and active low frequency filtering: U2, R1, R2, R3, C1 form addition and the active low-frequency filter circuit of the first order, realize 2.5V quantitative compensation and active low frequency filtering.Wherein U2, R1, R2, R3, composition adding circuit are realized the 2.5V quantitative compensation, export DC component (R3=R4) V2=-2.5V * R3/R4=-2.5V of U2 output at this moment behind DC component process R2, R3, the U2.U2, R1, R3, C1 form the active low-frequency filter circuit of the first order simultaneously.U3, R4, R5, C2 form phase inverter and the active low-frequency filter circuit in the second level.U3, R4, R5 form phase inverter, for DC component, and DC component (R4=R5) V3=-V2 * R5/R4=+2.5V of U3 output.U3, R4, R5, C2 form the active low-frequency filter circuit in the second level simultaneously.U4---voltage follower is realized the isolation of active power filtering and 2.5V quantitative compensation circuit and output circuit, and has been improved fan-out capability again.

Limiter protection circuit and the passive filter circuit of output 0～5V: D1, D2, D3, R6, R7, C3 form limiter protection circuit and the passive filter circuit of output 0～5V.D1, D2 are called clamp diode, constitute limited amplitude protection; R6, C3 form passive filter circuit.

When U4 exported greater than 5V, voltage channel is: V4-R6-D1-+5V, VA were limited in+5.7V, UO=VA-VD3=+5.7V-0.7V=+5V, and D3 has played the effect of 0.7V pressure difference compensation at this.When U4 output during less than-0.7V, voltage channel is: ground-D2-R6-V4, and VA=-0.7V, D3 ends, and UO is communicated with earth potential by R7, UO=0V.

More than two kinds of situations, all have R6 to get involved, its objective is protection U4 output stage, play the effect of restriction electric current.

When U4 output-0.7V～+ during 0.7V, D3 still ends, UO is communicated with earth potential by R7, UO=0V.

In a word, VA is limited to+0.7V～+ 5.7V between, through D3+the 0.7V pressure difference compensation after, UO output is limited between 0～5V, so far, finishes the voltage signal conditioning.When U4 output between 0～5V, R6, C3 form passive filter circuit, further improve filter effect.

The above is single pass circuit and relative theory, can determine used number of active lanes according to what of collection capacity in the actual engineering of engineering.

Circuit is concrete to be connected as shown in Figure 2:

The pin one of precision voltage source LM336 is received the adjustment end of potentiometer, two stiff ends of W2 are received the anode of voltage stabilizing diode VD1 and the negative electrode of VD2 respectively, series resistor R8 between the negative electrode of VD1 and the pin two of LM336, the negative electrode of VD1 and the intersection point of R8 are linked to+the 5V power supply.The anode of VD2 is received the pin 3 of LM336, simultaneously is connected in series potentiometer W3, three's intersection point common ground between the pin 3 of LM336 and the pin two.The in-phase input end of single channel JFET entering apparatus LF411 is the adjustment end that pin 3 is received potentiometer W3, and pin two directly links to each other with pin 6, receives then; Pin 4 and the pin 5 of LF411 are received respectively ± the 15V power supply.

Input end Ui receives the two ends of potentiometer W1, and an end ground connection wherein.The adjustment end of W1 is directly received the pin 3 of LM324.

The pin one of integrated circuit LM324 and pin two are connected to the other end of R2 jointly by R1; And the other end of R2 is connected to the pin 7 of LM324 by resistance R 3 and capacitor C 1, and wherein R3 and C1 are relations in parallel, and this end is directly connected to the pin 6 of LM324 simultaneously.Pin 5, pin one 0, pin one 1 common ground, pin 4 is received+the 15V power supply.Series resistor R4 between pin 7 and the pin 9, pin 9 is connected to pin 8 and pin one 2 by R5 and C2, and wherein R5 and C2 are relations in parallel.Pin one 3 and pin one 4 are received an end of resistance R 6 jointly.The other end of R6 is received the anode of diode D1, D3 and the negative electrode of D2 respectively, and the negative electrode of D1 connects+the 5V power supply, and capacitor C 3 is connected in parallel on the two ends of D2, and the anode of D2 is received an end of resistance R 7, and this intersection point ground connection.The other end of R7 and the negative electrode of D3 are received the output terminal Uo of way circuit jointly.

Claims

1, voltage signal modulate circuit, comprise reference circuit circuit, passive low-pass filter circuit, voltage follower circuit, it is characterized in that: this circuit also comprises the active low-frequency filter circuit of the two-stage that is connected between reference circuit circuit and the passive low-pass filter circuit, quantitative compensation circuit and limiter protection circuit, and voltage follower circuit is arranged between active low-frequency filter circuit of two-stage and the limiter protection circuit; Wherein quantitative compensation circuit and active low-frequency filter circuit are used for 2.5V quantitative compensation and active low frequency filtering; Limiter protection circuit is used for carrying out amplitude limiting processing to exporting 0～5V voltage signal.

2, voltage signal modulate circuit according to claim 1 is characterized in that: described limiter protection circuit comprises the clamp diode by the clamp diode of tie point and the+sensing noble potential that 5V links to each other and the sensing noble potential that links to each other with ground.

3, voltage signal modulate circuit according to claim 1 and 2 is characterized in that: the active low-frequency filter circuit of the first order is used for the voltage quantitative compensation in the active low-frequency filter circuit of described two-stage, and DC component is output as-2.5V; The active low-frequency filter circuit in the second level comprises inverter circuit, and DC component is output as+2.5V.