CN111464006A

CN111464006A - Inductive load driving circuit

Info

Publication number: CN111464006A
Application number: CN202010376460.XA
Authority: CN
Inventors: 陶国良; 陶勇
Original assignee: Zhejiang Taoyuan Intelligent Technology Co ltd
Current assignee: Zhejiang Taoyuan Intelligent Technology Co ltd
Priority date: 2020-05-07
Filing date: 2020-05-07
Publication date: 2020-07-28
Anticipated expiration: 2040-05-07
Also published as: CN111464006B

Abstract

The invention relates to the technical field of driving circuits, in particular to an inductive load driving circuit. The method comprises the following steps: the charging circuit comprises a power supply loop, a control circuit, a main circuit and a charging capacitor; the power supply loop outputs power supply voltage to the charging capacitor to charge the charging capacitor; the charging capacitor outputs a low level signal to the control circuit until charging is completed; the control circuit outputs a high level signal to the main circuit according to the low level signal; when the charging of the charging capacitor is finished, the control circuit outputs a rectangular wave signal to the main circuit; the main circuit controls output current according to the high level signal and the rectangular wave signal. In the prior art, the inductive load is easy to burn and damage when being operated for a long time. Compared with the prior art, the method has the advantages that the starting state of the inductive load can be maintained when the output current is reduced by utilizing the inductive characteristic of the inductive load, so that the running power consumption is reduced, the heat generated by running is reduced, the combustion damage of the inductive load is effectively prevented, and the stability of the inductive load in long-term running is improved.

Description

Inductive load driving circuit

Technical Field

The invention relates to the technical field of driving circuits, in particular to an inductive load driving circuit.

Background

The inductive load refers to a load with a phase difference characteristic of load current lagging load voltage, and with the continuous development of technology, the inductive load is widely applied to various devices. When the inductive load runs for a long time, current needs to continuously flow through the inductive load, and the inductive load is influenced by the heat effect of the current, so that heat generated by the inductive load during running can be continuously generated, and the generated heat is continuously accumulated along with the increase of the running time, and the inductive load is burnt and damaged.

Disclosure of Invention

In view of the technical problems in the prior art, the present invention provides an inductive load driving circuit.

In order to solve the technical problems, the invention provides the following technical scheme:

an inductive load driving circuit comprising: the charging circuit comprises a power supply loop, a control circuit, a main circuit and a charging capacitor; the power supply loop outputs power supply voltage to the charging capacitor to charge the charging capacitor; the charging capacitor outputs a low level signal to the control circuit until charging is completed; the control circuit outputs a high level signal to the main circuit according to the low level signal; when the charging of the charging capacitor is finished, the control circuit outputs a rectangular wave signal to the main circuit; the main circuit controls output current according to the high level signal and the rectangular wave signal.

The power is supplied to the charging capacitor through the power supply loop, and the voltage at two ends of the charging capacitor cannot change suddenly under the impression of the characteristics of the capacitor, so that the charging capacitor outputs a low-level signal to the control circuit in the charging process of the charging capacitor. At this time, the control circuit outputs a high level signal to the main circuit, and the main circuit receives the high level signal to output current to the inductive load, so as to meet the excitation requirement of the inductive load and further start the inductive load. The charging capacitor finishes charging along with the time, at the moment, the control circuit outputs a rectangular wave signal to the main circuit, the main circuit reduces the magnitude of output current according to the duty ratio of the rectangular wave signal, the inductive load is influenced by inductive characteristics, and the current flowing through the inductive load cannot suddenly change, so that when the output current of the main circuit is reduced, the inductive load can still be maintained in a starting state, the current of the inductive load in long-term operation is reduced, the power consumption of the inductive load in long-term operation is further reduced, and the heat productivity of the inductive load in operation is reduced. Therefore, the inductive load is effectively prevented from being burnt due to overheating, and the stability of the inductive load during operation is improved.

Furthermore, the device also comprises an input rectifying and filtering circuit; the input rectification filter circuit is electrically connected with the power supply to receive power supply voltage, and outputs filter voltage to the power supply loop according to the power supply voltage; the power supply loop outputs power supply voltage to the charging capacitor according to the filtering voltage.

Further, the power supply loop comprises a resistor R4, a resistor R3, a triode, a diode D4 and a capacitor C3; one end of the resistor R4 is electrically connected with the rectifying and filtering circuit to filter voltage, and the other end of the resistor R4 is electrically connected with one end of the resistor R3 and the collector of the triode; the other end of the resistor R3 is electrically connected with the base electrode of the triode and the negative electrode of the diode D4; one electrode of the capacitor C3 is electrically connected with the emitter of the triode, and the other electrode of the capacitor C3 is electrically connected with the anode of the diode D4 and the charging capacitor.

Further, the charging capacitor comprises a capacitor C2 and a capacitor C4; the capacitor C2 receives the supply voltage output by the capacitor C3; the capacitor C4 receives the supply voltage output by the capacitor C3; the capacitor C2 and the capacitor C4 output low level signals to the control circuit until charging is completed.

Further, the control circuit comprises a timer chip; the timer chip receives low level signals output by the capacitor C2 and the capacitor C4; the timer chip outputs a high level signal to the main circuit; when the charging of the capacitor C2 and the capacitor C4 is completed, the timer chip outputs a rectangular wave signal to the main circuit.

Further, the control circuit further comprises a resistor R5, a resistor R2, a diode D1, a diode D2 and a diode D3; the resistor R5 and the resistor R2 are electrically connected with the timer chip; one end of the resistor R5 is electrically connected with the cathode of the diode D1, and the other end of the resistor R5 is electrically connected with one end of the resistor R2; the other end of the resistor R2 is electrically connected with one pole of the capacitor C4 and the positive pole of the diode D2; the cathode of the diode D2 is electrically connected with the anode of the diode D1 and one electrode of the capacitor C2; the diode D3 is connected in parallel with the resistor R2, and the diode D3 is electrically connected to the timer chip.

Furthermore, the main circuit comprises a driving MOS tube and a freewheeling diode; the fly-wheel diode is electrically connected with the driving MOS tube, and two ends of the fly-wheel diode are provided with output ends; the driving MOS tube is switched on or switched off according to the high level signal and the rectangular wave signal to control the output current at two ends of the fly-wheel diode.

Further, when the driving MOS tube receives a high level signal, the driving MOS tube is conducted; when the driving MOS tube receives the rectangular wave signal, the driving MOS tube is circularly switched on and off according to the rectangular wave signal.

Further, the main circuit also comprises a resistor R1; the resistor R1 outputs the high level signal and the rectangular wave signal input by the control circuit to the driving MOS tube.

Compared with the prior art, the invention has the following advantages:

the timer chip sequentially outputs a high-level signal and a rectangular wave signal according to the charging state, and the high-level signal meets the excitation requirement of the inductive load, so that the inductive load is started. The output current is reduced by utilizing the rectangular wave signal, and the inductive characteristic of the inductive load is utilized, so that the inductive load can still maintain the starting state when the current is reduced, the power consumption of the inductive load is reduced, the heat generated by the inductive load is reduced, the inductive load is not easy to burn due to overheating, and the running stability of the inductive load is improved.

When the charging capacitor is electrified, the timer chip can output a high-level signal in time, so that the response speed of the invention is improved.

The fact that the voltage at the two ends of the capacitor cannot suddenly change is the inherent characteristic of the charging capacitor, so that the high-level signal and the rectangular wave signal can be normally output when the power supply voltage fluctuates, and therefore the anti-interference capacity of the high-level voltage source is effectively improved.

Drawings

FIG. 1: and (4) an overall circuit diagram.

FIG. 2: and inputting the input into a rectifying and filtering circuit.

FIG. 3: a power supply loop and a control circuit.

FIG. 4: a main circuit.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

An inductive load driving circuit comprising: the device comprises an input rectification filter circuit, a power supply loop, a control circuit, a main circuit and a charging capacitor. The input rectifying and filtering circuit comprises a diode D5, a diode D6, a diode D7, a diode D8 and a filter capacitor C1. The cathode of the diode D7 is electrically connected to the cathode of the diode D8 and one electrode of the filter capacitor C1, and the anode of the diode D7 is electrically connected to the cathode of the diode D6. The cathode of the diode D5 is electrically connected to the anode of the diode D8, and the anode of the diode D5 is electrically connected to the anode of the diode D6 and the other electrode of the smoothing capacitor C1. The anode of the diode D7 is further provided with a first power input terminal VIN1, and the anode of the diode D8 is further provided with a second power input terminal VIN 2. A voltage dependent resistor M1 is further disposed between the first power input terminal VIN1 and the second power input terminal VIN 2. The input rectifying and filtering circuit is electrically connected to the power supply through the first power input terminal VIN1 and the second power input terminal VIN2, so as to obtain the power supply voltage. The filter capacitor C1 outputs a filtered voltage to the power supply circuit through the received power supply voltage.

The power supply loop comprises a resistor R4, a resistor R3, a triode Q1, a diode D4 and a capacitor C3. One end of the resistor R4 is electrically connected to one of the diode D7, the diode D8, and the filter capacitor C1 for receiving the filter voltage. The other end of the resistor R4 is electrically connected to one end of the resistor R3 and the collector of the transistor Q1. The other end of the resistor R3 is electrically connected with the base of the triode Q1 and the cathode of the diode D4. The capacitor C3 and the emitter of the transistor Q1 are electrically connected, and the other pole of the capacitor C3 is electrically connected to the anode of the diode D4, one pole of the capacitor C2, and one pole of the capacitor C4.

The control circuit comprises a timer chip, a resistor R5, a resistor R2, a diode D1, a diode D2 and a diode D3. In this embodiment, the timer chip is a 555 chip. One end of the resistor R5 is electrically connected with the pin 4 and the pin 8 of the timer chip, and one end of the resistor R5 is also electrically connected with the cathode of the diode D1 and the emitter of the triode Q1. The other end of the resistor R5 is also electrically connected with the pin 7 of the timer chip 555 and one end of the resistor R2. The other end of the resistor R2 is electrically connected to one electrode of the capacitor C4 and the anode of the diode D2. The other end of the resistor R2 is also electrically connected with

pins

2 and 6 of the timer chip. The cathode of the diode D2 is electrically connected to the anode of the diode D1 and one of the capacitors C2. The diode D3 is connected in parallel with the resistor R2, the cathode of the diode D3 is electrically connected to

pins

2 and 6 of the timer chip, and the anode of the diode D3 is electrically connected to pin 7 of the timer chip.

When the capacitors C2 and C4 obtain the power supply voltage through the capacitor C3, the voltages at the two ends of the capacitors C2 and C4 cannot change abruptly due to the influence of the characteristics of the capacitors themselves, so that the voltage at the two ends of the capacitor C2 is at a low level and the voltage at the two ends of the capacitor C4 is at a low level. Accordingly, the capacitor C2 and the capacitor C4 output low level signals to the timer chip, so that

pins

2, 6 and 7 of the timer chip are at low level, and at this time, the timer chip outputs high level signals through pin 3. Meanwhile, the capacitor C3 charges the capacitor C2 through the resistor R2, the resistor R5, the diode D3 and the diode D4. The capacitor C3 charges the capacitor C4 through the resistor R2, the resistor R5 and the diode D3. In the present embodiment, as the voltages at the two ends of the capacitor C2 and the capacitor C4 gradually increase, the voltage value at the pin 7 of the timer chip also gradually increases. When the voltage values at the two ends of the capacitor C2 and the capacitor C4 reach two thirds of the voltage required by the timer chip to operate at full power, the charging of the capacitor C2 and the capacitor C4 is completed. Under the influence of the characteristics of the timer chip, the voltages required for charging the charging point capacitor C2 and the capacitor C4 are different for different timer chips. At this time, the 3 pins of the timer chip output the rectangular wave signal to the main circuit.

The main circuit comprises a resistor R1, a driving MOS tube N1 and a freewheeling diode D9. One end of the resistor R1 is electrically connected to the 3-pin of the timer chip to receive the high-level signal and the rectangular wave signal output by the 3-pin. The other end of the resistor R1 is electrically connected with the gate of the driving MOS transistor N1. The drain of the driving MOS transistor N1 is electrically connected to the anode of the freewheeling diode D9. The two ends of the freewheeling diode D9 are also provided with a positive output end and a negative output end. When the pin 3 of the timer chip outputs a high level signal, the driving MOS transistor N1 is turned on, so that current is output to the inductive load through the positive output terminal and the negative output terminal, and voltage is loaded to both ends of the inductive load to meet the requirement of exciting the inductive load, thereby starting the inductive load. When the 3-pin of the timer chip outputs the rectangular wave signal, the driving MOS transistor N1 is in a cyclic state from on to off and from off to on, thereby reducing the magnitude of the output current. When the driving MOS tube is closed, the inductive load is influenced by self inductance, the current flowing through the inductive load cannot change suddenly, and the freewheeling diode D9 freewheels. Thus, when the output current is reduced, the starting state of the inductive load can still be effectively maintained.

In summary, the timer chip can output a high level signal or a rectangular wave signal according to the charging state of the charging capacitor by using the characteristic that the voltage at two ends of the capacitor cannot change suddenly, so as to control the output current. On one hand, the excitation requirement of the inductive load is met through the high-level signal, on the other hand, the magnitude of the output current is reduced through the rectangular wave signal, and the inductive characteristic of the inductive load is utilized, so that the inductive load can still maintain the starting state even under the condition that the output current is reduced. Therefore, the circulating current of the inductive load during long-term operation is effectively reduced, the power consumption of the inductive load is reduced, the heat generated during long-term operation of the inductive load is reduced, the inductive load is not easy to burn and damage due to overheating, and the operation stability of the inductive load is effectively improved.

Meanwhile, when the charging capacitor is electrified, the timer chip can output a high-level signal in time, so that the response speed of the circuit is effectively improved. The timer chip outputs a high level signal or a rectangular wave signal only influenced by the charging state of the charging capacitor, and the voltage at two ends of the capacitor can not change suddenly, which is the inherent characteristic of the charging capacitor, so that even if the power supply voltage output by the power supply loop fluctuates, the signal output by the timer chip can still be converted into the rectangular wave signal from the high level signal, and the anti-interference capability of the invention is effectively improved.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims

1. An inductive load driving circuit, comprising: the method comprises the following steps: the charging circuit comprises a power supply loop, a control circuit, a main circuit and a charging capacitor;

the power supply loop outputs power supply voltage to the charging capacitor to charge the charging capacitor;

the charging capacitor outputs a low level signal to the control circuit until charging is completed;

the control circuit outputs a high level signal to the main circuit according to the low level signal;

when the charging of the charging capacitor is finished, the control circuit outputs a rectangular wave signal to the main circuit;

and the main circuit controls output current according to the high level signal and the rectangular wave signal.

2. An inductive load driving circuit according to claim 1, wherein: the input rectifying filter circuit is also included;

the input rectifying and filtering circuit is electrically connected with a power supply to receive power supply voltage, and outputs filtering voltage to the power supply loop according to the power supply voltage;

and the power supply loop outputs power supply voltage to the charging capacitor according to the filtering voltage.

3. An inductive load driving circuit according to claim 2, wherein: the power supply loop comprises a resistor R4, a resistor R3, a triode, a diode D4 and a capacitor C3;

one end of the resistor R4 is electrically connected with the rectifying and filtering circuit to receive the filtering voltage, and the other end of the resistor R4 is electrically connected with one end of the resistor R3 and the collector of the triode;

the other end of the resistor R3 is electrically connected with the base electrode of the triode and the negative electrode of the diode D4;

one pole of the capacitor C3 is electrically connected with the emitter of the triode, and the other pole of the capacitor C3 is electrically connected with the anode of the diode D4 and the charging capacitor.

4. An inductive load driving circuit according to claim 3, wherein: the charging capacitor comprises a capacitor C2 and a capacitor C4;

the capacitor C2 receives the supply voltage output by the capacitor C3;

the capacitor C4 receives the supply voltage output by the capacitor C3;

the capacitor C2 and the capacitor C4 output the low level signal to the control circuit until charging is completed.

5. An inductive load driving circuit according to claim 4, wherein: the control circuit comprises a timer chip;

the timer chip receives low level signals output by the capacitor C2 and the capacitor C4;

the timer chip outputs the high level signal to the main circuit;

when the charging of the capacitor C2 and the capacitor C4 is completed, the timer chip outputs the rectangular wave signal to the main circuit.

6. An inductive load driving circuit according to claim 5, wherein: the control circuit further comprises a resistor R5, a resistor R2, a diode D1, a diode D2 and a diode D3;

the resistor R5 and the resistor R2 are electrically connected with the timer chip;

one end of the resistor R5 is electrically connected with the cathode of the diode D1, and the other end of the resistor R5 is electrically connected with one end of the resistor R2;

the other end of the resistor R2 is electrically connected with one pole of the capacitor C4 and the anode of the diode D2;

the cathode of the diode D2 is electrically connected with the anode of the diode D1 and one pole of the capacitor C2;

the diode D3 is connected in parallel with the resistor R2, and the diode D3 is electrically connected with the timer chip.

7. An inductive load driving circuit according to claim 1, wherein: the main circuit comprises a driving MOS tube and a freewheeling diode;

the freewheeling diode is electrically connected with the driving MOS tube, and output ends are arranged at two ends of the freewheeling diode;

and the driving MOS tube is switched on or switched off according to the high level signal and the rectangular wave signal to control the output current at two ends of the freewheeling diode.

8. The inductive load driving circuit of claim 7, wherein: when the driving MOS tube receives the high level signal, the driving MOS tube is conducted;

and when the driving MOS tube receives the rectangular wave signal, the driving MOS tube is circularly switched on and off according to the rectangular wave signal.

9. The inductive load driving circuit of claim 7, wherein: the main circuit further comprises a resistor R1;

the resistor R1 outputs the high level signal and the rectangular wave signal input by the control circuit to the driving MOS tube.