CN207673927U - A kind of New Type Proportional valve-driving circuit - Google Patents

Abstract

The utility model relates to a new proportional valve driving circuit, which is characterized in that it includes a signal acquisition circuit, a signal compensation circuit, a signal isolation drive amplification circuit, a triangular wave generation circuit, a voltage reference circuit and an anti-power reverse connection circuit; the signal acquisition circuit is connected Input signal and voltage reference circuit, the output end of the signal acquisition circuit is connected to the signal compensation circuit, the output end of the signal compensation circuit is connected to the signal isolation drive amplifier circuit, the triangular wave generating circuit end is connected to the signal isolation drive amplifier circuit, and the output of the signal isolation drive amplifier circuit is turned on Signal and OFF signal are used for drive control. The utility model has a reasonable design and avoids the interference of the high-frequency pulse generated by the rapid turn-on and cut-off of the proportional valve coil on the control system. The signal isolation drive amplifier circuit adopts PWM pulse width modulation technology, which can be applied to various types of proportional valve coils. , stronger adaptability and superior adjustment performance.

Description

A New Proportional Valve Driving Circuit

technical field

The utility model belongs to the technical field of governors, in particular to a novel proportional valve drive circuit.

Background technique

With the advancement of technology, the governor industry is increasingly upgrading its products to high oil pressure proportional valve governors. This kind of governor has the advantages of low cost and simple structure. It is the mainstream trend of industry development and the first choice for power station renovation. The driver of the proportional valve is the key component of the above-mentioned high oil pressure proportional governor. Most manufacturers choose imported products, which are expensive and have a long procurement cycle. It has great limitations in use. If you encounter special requirements, you need to add additional hardware to meet the use requirements, resulting in high hardware costs, and it cannot be well connected with the output of mainstream PLC products (0 ~ 10V , -10V ~ 10V, 4 ~ 20mA), and did not take into account the complex working conditions of the power station, and did not effectively isolate the control power supply and the proportional valve drive power supply.

Utility model content

The purpose of the utility model is to overcome the deficiencies of the prior art, and propose a new proportional valve drive circuit with reasonable design, low cost and wide application range.

The utility model solves its technical problem and realizes by taking the following technical solutions:

A novel proportional valve drive circuit, comprising a signal acquisition circuit, a signal compensation circuit, a signal isolation drive amplifier circuit, a triangular wave generation circuit, a voltage reference circuit and an anti-power reverse connection circuit; the signal acquisition circuit is connected to an input signal and a voltage reference circuit, The output end of the signal acquisition circuit is connected to a signal compensation circuit, and the output end of the signal compensation circuit is connected to a signal isolation drive amplifier circuit. The signal isolation drive amplifier circuit includes an open signal isolation drive amplifier circuit and a close signal isolation drive amplifier circuit. The triangular wave The output terminal of the generating circuit is connected to the open signal isolation drive amplifier circuit and the close signal isolation drive amplifier circuit, and the open signal isolation drive amplifier circuit and the close signal isolation drive amplifier circuit respectively output the open signal and the close signal for drive control; The anti-power supply reverse connection circuit is connected with the external power supply to realize the protection function for the external power supply connected to the driving circuit.

The input signal connected to the signal acquisition circuit is: the voltage is 0-10VDC or -10-+10VDC, the current is 0/4-20mA; the output signal is -10-+10VDC.

The signal acquisition circuit includes an addition circuit and three switches. The input signal is connected to the grounding resistor through the first switch to convert the current and voltage signals and output to the addition circuit. The input signal is connected to the second switch at the same time, and the output of the addition circuit is connected to the third switch. , 0-10VDC and -10-+10VDC are output as -10-+10VDC signals through the switching control of the second switch and the third switch.

The signal compensation circuit includes a positive voltage signal compensation circuit and a negative voltage signal compensation circuit, the positive voltage signal compensation circuit and the negative voltage signal compensation circuit are connected to the -10 to 10V voltage signal output by the signal acquisition circuit, and are respectively connected to the input positive voltage signal Voltage signal and negative voltage signal are compensated.

The open-to signal isolation drive amplifier circuit is connected to the positive voltage signal output by the signal compensation circuit, and the positive voltage signal is superimposed and compared with the WAVE voltage output by the triangular wave circuit to obtain a PWM voltage signal. The PWM voltage signal is passed through an optocoupler, The Linton tube output drives the opening proportional valve coil; the closing signal isolation driving amplifier circuit is connected with the negative voltage signal output by the signal compensation circuit, and the PWM voltage is obtained by comparing the negative voltage signal with the WAVE voltage output by the triangular wave circuit after superimposing the negative voltage signal Signal, the PWM voltage signal is output by the optocoupler and Linton tube to drive the proportional valve coil.

Advantage and positive effect of the present utility model are:

1. The signal acquisition circuit of the present utility model can isolate and sample the following signals: 0～10VDC, -10～+10VDC, 0/4～20mA, and can also directly receive the PWM signal of the PLC high-speed port. Therefore, its input signal adaptability is strong.

2. This utility model aims at the defect that the power supply of the traditional proportional valve drive module is not isolated. We separate the two sets of power supplies with a high-speed optocoupler, which avoids the interference of the high-frequency pulse generated by the rapid conduction and cut-off of the proportional valve coil on the control system. It provides guarantee for the safe operation of PLC and the reliable and stable acquisition of analog signals, so as to realize the complete isolation function of control power supply and proportional valve drive power supply.

3. The signal isolation driving amplifying circuit of the present invention adopts PWM pulse width modulation technology, and the PWM cycle is adjustable, which can be applied to various types of proportional valve coils and has stronger adaptability.

4. The driving parameters such as the two-way driving base value, dead zone, and magnification of the proportional valve switch of the utility model can be adjusted independently, and the adjustment performance is superior.

Description of drawings

Fig. 1 is a schematic diagram of the utility model;

Fig. 2 is a signal acquisition circuit diagram of the present utility model;

Fig. 3 is a signal compensation circuit diagram of the present utility model;

Fig. 4a is a circuit diagram of an open direction signal isolation drive amplification circuit of the present invention;

Fig. 4b is a circuit diagram of the isolation drive amplification circuit of the off direction signal of the present invention;

Fig. 5 is a triangular wave generating circuit diagram of the present utility model;

Fig. 6 is a voltage reference circuit diagram of the utility model;

Fig. 7 is a circuit diagram of the anti-power reverse connection of the utility model.

Detailed ways

Embodiments of the utility model are described in further detail below in conjunction with the accompanying drawings.

A new type of proportional valve drive circuit, as shown in Figure 1, includes a signal acquisition circuit, a signal compensation circuit, a signal isolation drive amplifier circuit, a triangular wave generation circuit, a voltage reference circuit and an anti-power reverse connection circuit. The signal acquisition circuit is connected to the input signal (0～10VDC, -10V～10VDC, 4～20mA) and the voltage reference circuit, the output end of the signal acquisition circuit is connected to the signal compensation circuit, and the output end of the signal compensation circuit is connected to the signal isolation driving amplifier circuit The signal isolation drive amplifier circuit includes an open signal isolation drive amplifier circuit and a close signal isolation drive amplifier circuit, and the triangular wave generating circuit outputs a triangular waveform signal to the open signal isolation drive amplifier circuit and the close signal isolation drive amplifier circuit respectively. , the on-signal isolation drive amplifying circuit and the off-direction signal isolation drive amplifying circuit respectively output the on signal and the off signal for drive control. The anti-power supply reverse connection circuit is connected with the external power supply to realize the protection function for the external power supply connected to the driving circuit. Each part of the drive circuit is described below:

As shown in Figure 2, the structure of the signal acquisition circuit is: the input signal is connected to the IN terminal, and R47 is a precision sampling resistor, which converts the current signal into a voltage signal. If the input signal is -10~10V voltage signal, then S1C will be closed and S1B will be open; if the input signal is 0~10V voltage signal, then S1B will be closed and S1C will be open. After the addition circuit composed of N1B and N1C, a +5V (Vref ) signal is amplified twice at the same time, and becomes a -10~10V voltage signal. That is: no matter what kind of signal, it is converted into a standard -10 ~ 10V voltage signal through the circuit and input to the next stage circuit. The characteristics of this acquisition circuit are: strong adaptability to input signals, can isolate and sample the following signals: 0~10VDC, -10~+10VDC, 0/4~20mA, and can also directly receive PWM signals from PLC high-speed ports.

As shown in Figure 3, the structure of the signal compensation circuit is: the -10~10V voltage signal output by the signal acquisition circuit enters the middle position of the circuit. If the voltage is positive, and the voltage is greater than the threshold value set by the test terminal T2 (adjusted by RP2), the upper part of the circuit will work, that is, the output voltage of the circuit will be superimposed on the original input voltage with a base value (set by RP6), and at the same time amplified A certain multiple (set by RP4). If the input voltage is positive and the voltage is lower than the threshold value set by the test terminal T2 (adjusted by RP2), the final output of the entire circuit is zero. The threshold value set by T2 can be regarded as the dead zone of the circuit. In the same way, if the input voltage is negative, the lower half of the circuit works, and the principle is the same as above. The characteristics of this signal compensation circuit are: the driving parameters such as the two-way driving base value of the proportional valve switch, the dead zone, and the magnification can be adjusted independently, and the adjustment performance is superior.

As shown in FIG. 4 a and FIG. 4 b , the signal isolation driving amplifying circuit includes an isolation driving amplifying circuit including an opening signal isolation driving amplifying circuit and a closing signal isolation driving amplifying circuit. The -10-10V voltage signal output by the signal compensation circuit enters the signal isolation drive amplifier circuit. If the signal output by the signal compensation circuit is positive, it will work in the signal isolation drive amplifier circuit. After the positive voltage is superimposed on the T8 voltage, and compared with the WAVE voltage (triangular wave circuit output), the PWM signal is obtained. The higher the positive voltage, the higher the PWM signal. The larger the empty ratio, the proportional valve drive of this circuit adopts PWM pulse width modulation technology, and the PWM period is adjustable. After the PWM voltage signal is isolated by the BO1A optocoupler, the final output of the Darlington tube V1 drives the proportional valve coil. In this way, the control power supply and the proportional valve drive power supply are completely isolated. In the figure, VD3 is a freewheeling diode, and R52 and R53 are current-limiting sampling resistors. If the signal output by the signal compensation circuit is negative, the signal isolation drive amplifier circuit is turned off, and its structure and working principle are the same as above.

As shown in Figure 5, the triangular wave generating circuit uses RP7 to fine-tune the frequency of the triangular wave, and the waveform is output from the WAVE terminal. This circuit cooperates with the signal isolation drive amplifier circuit to realize PWM pulse width modulation and adjustable PWM period.

As shown in Figure 6, the voltage reference circuit can adjust the reference voltage by adjusting RP1.

As shown in Figure 7, the anti-reverse power supply circuit uses diodes VD5, VD6, and VD7 to prevent reverse connection of the input power supply.

It should be emphasized that the embodiments described in the utility model are illustrative rather than restrictive, so the utility model is not limited to the embodiments described in the specific implementation, anyone skilled in the art according to the utility model Other implementations derived from the technical solution also belong to the protection scope of the present utility model.

Claims (5)

1. a kind of New Type Proportional valve-driving circuit, it is characterised in that：Including signal acquisition circuit, signal compensation circuit, signal every From drive amplification circuit, triangle wave generating circuit, voltage reference circuit and anti-reverse power connection circuit；The signal acquisition circuit connects Input signal and voltage reference circuit are connect, the signal acquisition circuit output connection signal compensation circuit, the signal compensation circuit Output end connection signal isolation drive amplifying circuit, the signal isolation drive amplification circuit include being opened to signal isolation drive amplification It circuit and closes to signal isolation drive amplification circuit, the triangle wave generating circuit output end connection is opened to signal isolation driving and puts It big circuit and closes to signal isolation drive amplification circuit, is driven from being opened to signal isolation drive amplification circuit and closing to signal isolation Amplifying circuit exports ON signal respectively and OFF signal is used for drive control；The anti-reverse power connection circuit is connected with external power supply Realize the defencive function to external plant-grid connection driving circuit.

2. a kind of New Type Proportional valve-driving circuit according to claim 1, it is characterised in that：The signal acquisition circuit connects The input signal connect is：Voltage is 0~10VDC or -10~+10VDC, and electric current is 0/4~20mA；Output signal be -10~+ 10VDC。

3. a kind of New Type Proportional valve-driving circuit according to claim 2, it is characterised in that：The signal acquisition circuit packet Add circuit and three switches are included, input signal carries out current and voltage signals conversion through first switch connection ground resistance and exports To add circuit, input signal connects second switch simultaneously, and the add circuit output connection third switch passes through second switch It is -10~+10VDC signals that switch control with third switch, which exports 0~10VDC and -10~+10VDC,.

4. a kind of New Type Proportional valve-driving circuit according to claim 2, it is characterised in that：The signal compensation circuit packet Include positive voltage signal compensation circuit and negative voltage signal compensation circuit, positive voltage signal compensation circuit and negative voltage signal compensation electricity Road is connected with -10~10V voltage signals that signal acquisition circuit exports, and respectively to the positive voltage signal of input and negative voltage Signal compensates.

5. a kind of New Type Proportional valve-driving circuit according to claim 2, it is characterised in that：It is described to be opened to signal isolation drive Dynamic amplifying circuit is connected with the positive voltage signal that signal compensation circuit exports, and positive voltage signal is overlapped rear and triangular wave The WAVE voltages of circuit output relatively obtain PWM voltage signals, which is opened to through optocoupler, Islington pipe output driving Ratio valve coil；Described close to signal isolation drive amplification circuit is connected with the negative voltage signal that signal compensation circuit exports, WAVE voltages after negative voltage signal is superimposed with triangle wave circuit output relatively obtain PWM voltage signals, the PWM voltage signals It is closed to ratio valve coil through optocoupler, Islington pipe output driving.