A proportional valve wet pto control circuit

Abstract

The application relates to a proportional valve wet type PTO control circuit which comprises a power-on switch J1, a triode Q1, a triode Q2, a stabilizing tube Z1, a stabilizing tube Z3, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a capacitor C3, a capacitor C4, a capacitor C5, a voltage stabilizer U1, an OR gate U2, a voltage stabilizer U3, an amplifier U4, an amplifier U5 and a diode D1. The proportional valve wet type PTO control circuit provided by the application has the advantages of fewer components, low cost, high reliability, simple and convenient switch control, adjustable time and good matching.

Description

Technical Field

[0001] This application relates to the field of proportional valves, and more particularly to a wet PTO control circuit for a proportional valve. Background Technology

[0002] The wet PTO of the tractor uses a proportional valve to control the clutch to achieve the engagement and disengagement of power. The engagement of the proportional valve is achieved by controlling the current through PWM pulse width modulation technology. Too fast or too slow will cause some damage to the clutch and damage the mechanical equipment.

[0003] PTO is a system that provides power to tractor-mounted implements. Currently, most systems use a controller that controls a proportional valve through a PWM current closed-loop to control the pressure and thus engage or disengage the clutch. However, due to the limited number of ports used and the high price, this results in wasted costs. Summary of the Invention

[0004] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this application provides a proportional valve wet PTO control circuit.

[0005] In a first aspect, this application provides a proportional valve wet PTO control circuit, comprising: a power-on switch J1, transistors Q1 and Q2, Zener diodes Z1 and Z3, resistors R1, R2, R3, R4, R5, R6, and R7, capacitors C3, C4, and C5, a voltage regulator U1, an OR gate U2, another voltage regulator U3, amplifiers U4 and U5, and a diode D1, wherein pin 1 of the power-on switch J1 is grounded and pin 2 is connected to... The transistor Q1 is connected to pin 2. Pin 1 of transistor Q1 is connected to the first terminal of resistor R3. The second terminal of resistor R3 is grounded. Pin 3 of transistor Q1 is connected to the first terminals of resistors R1 and R2, as well as pin 1 of voltage regulators U1 and U3. Pin 4 of voltage regulators U1 and U3 is grounded. Pin 3 of voltage regulator U3 is connected to the VCC terminal of amplifier U4. The second terminal of resistor R2 is connected to... The positive terminal of capacitor C3 is connected to the positive input terminal of amplifier U4. The second terminal of resistor R1 is connected to the first terminal of resistor R7 and the negative input terminal of amplifier U4. The negative terminal of capacitor C3 is connected to the second terminal of resistor R7, the VDD terminal of amplifier U4, and the negative terminal of capacitor C5. The output terminal of amplifier U4 is connected to the first terminal of resistor R6, the first input terminal of OR gate U2, and the anode of diode D1. The cathode of diode D1 is connected to the first terminal of resistor R5, the anode of capacitor C4, and the positive input terminal of amplifier U5. Pin 3 of voltage regulator U1 is connected to pin 2 of transistor Q2 and the VCC pin of amplifier U5. The first terminal of resistor R4 is connected to the output terminal of OR gate U2 and pin 1 of transistor Q2. The negative input terminal of amplifier U5 is connected to its own output terminal. The output terminal of amplifier U5 is grounded through a voltage-bearing resistor. The VDD terminal of amplifier U5 is grounded.

[0006] Preferably, it further includes: a capacitor C1, the positive terminal of which is connected to the first end of the resistor R2, and the negative terminal of which is grounded.

[0007] Preferably, it further includes: a capacitor C2, the positive terminal of which is connected to the first end of the resistor R2, and the negative terminal of which is grounded.

[0008] Preferably, it further includes: a Zener diode Z2, the anode of the Zener diode Z2 being grounded, and the cathode of the Zener diode Z2 being connected to the first end of the resistor R2.

[0009] Preferably, it further includes: a Zener diode Z3, the cathode of which is connected to the negative terminal of the capacitor C5, and the anode of which is grounded.

[0010] Preferably, it further includes a diode D2, the two ends of which are respectively connected to the two ends of the voltage-bearing resistor.

[0011] Preferably, the resistor R1 is a sliding rheostat.

[0012] Preferably, the resistor R2 is a sliding rheostat.

[0013] Preferably, the resistor R5 is a sliding rheostat.

[0014] Preferably, the resistor R6 is a sliding rheostat.

[0015] The technical solutions provided in this application have the following advantages compared with the prior art:

[0016] The proportional valve wet PTO control circuit provided in this application has fewer components and lower cost; it is built with analog and digital chips, resulting in high reliability; it features simple and convenient switch control; and its timing is adjustable, providing good matching performance. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a proportional valve wet PTO control circuit provided in an embodiment of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] Figure 1 This is a schematic diagram of a proportional valve wet PTO control circuit provided in an embodiment of this application.

[0022] This application provides a proportional valve wet PTO control circuit, including: a power-on switch J1, transistors Q1 and Q2, Zener diodes Z1 and Z3, resistors R1, R2, R3, R4, R5, R6, and R7, capacitors C3, C4, and C5, a voltage regulator U1, an OR gate U2, an amplifier U4, an amplifier U5, and a diode D1. The power-on switch J1 has pin 1 grounded and pin 2 connected to the voltage regulators. Pin 2 of transistor Q1 is connected to the first terminal of resistor R3, the second terminal of resistor R3 is grounded, pin 3 of transistor Q1 is connected to the first terminals of resistors R1 and R2, and pin 1 of voltage regulators U1 and U3, pin 4 of voltage regulators U1 and U3 is grounded, pin 3 of voltage regulator U3 is connected to the VCC terminal of amplifier U4, and the second terminal of resistor R2 is connected to capacitor C. The positive terminal of capacitor C3 is connected to the positive input terminal of amplifier U4. The second terminal of resistor R1 is connected to the first terminal of resistor R7 and the negative input terminal of amplifier U4. The negative terminal of capacitor C3 is connected to the second terminal of resistor R7, the VDD terminal of amplifier U4, and the negative terminal of capacitor C5. The output terminal of amplifier U4 is connected to the first terminal of resistor R6, the first input terminal of OR gate U2, and the anode of diode D1. The cathode of diode D1 is connected to the first terminal of resistor R5, the anode of capacitor C4, and the positive input terminal of amplifier U5. Pin 3 of voltage regulator U1 is connected to pin 2 of transistor Q2 and the VCC pin of amplifier U5. The first terminal of resistor R4 is connected to the output terminal of OR gate U2 and pin 1 of transistor Q2. The negative input terminal of amplifier U5 is connected to its own output terminal. The output terminal of amplifier U5 is grounded through a voltage-bearing resistor. The VDD terminal of amplifier U5 is grounded.

[0023] This application provides a proportional valve wet PTO control circuit with the following control principle:

[0024] (1) When the PTO switch is closed, the system is powered on at 12V;

[0025] (2) System reverse connection protection: Q1, Z1 and R3 form a reverse connection protection function. When the power supply is reversed, Q1 does not meet the switching conditions and remains in the open state.

[0026] (3) Power supply filtering: C1, C2 and Z2 form a power supply filtering function to filter out ripple and high voltage spike pulses in the power supply and protect the stable operation of downstream devices.

[0027] (4) T1 stage implementation: After the system is powered on, R2 and C3 are responsible for time control, R1 and R7 provide the amplifier comparison voltage, and U3 limits the current. When the comparator positive voltage rises to the comparison point, the output logic level changes and enters the T2 stage.

[0028] (5) T2 stage implementation: Z3 Zener diode clamps the voltage to the current value required in T2 stage. When U4 outputs low, it enters T2 stage. R6 and C5 form a discharge system. When the discharge is completed, the logic levels at both ends of U2 are low at the same time, satisfying the Q2 conduction condition, and the system enters T3 stage.

[0029] (6) T3 stage implementation: When Q2 is turned on, due to the action of diode D1, the current can only charge C4 through R5, which is proportional to time. U1 controls the final current magnitude.

[0030] (7) Improve driving capability: U5 forms a voltage follower, increases the input impedance and decreases the output impedance, thereby improving the driving capability.

[0031] Specifically, power switch J1 is used to power on the control system and also serves as the PTO control switch; transistors Q1 and Q2 are P-MOSFETs, IPD50P03P4L; Zener diode Z1 is BZT52C10; resistors R3 and R4 are 10KΩ; capacitors C3, C4, and C5 are 100 uF electrolytic capacitors; resistor R7 is a 1 KΩ resistor; voltage regulator U3 is a 78M08; amplifier U4 is an LM358+74HC14; OR gate U2 is a 74LS32; voltage regulator U1 is a 78M10; diode D1 is an IN4148; amplifier U5 is an LM358.

[0032] In this embodiment of the application, the proportional valve wet PTO control circuit provided in this application further includes: a capacitor C1, the positive terminal of the capacitor C1 is connected to the first terminal of the resistor R2, and the negative terminal of the capacitor C1 is grounded.

[0033] Specifically, capacitor C1 is a 470uF electrolytic capacitor.

[0034] In this embodiment of the application, the proportional valve wet PTO control circuit provided in this application further includes: a capacitor C2, the positive terminal of the capacitor C2 is connected to the first terminal of the resistor R2, and the negative terminal of the capacitor C2 is grounded.

[0035] Specifically, capacitor C2 is a 0.1uF filter capacitor.

[0036] In this embodiment of the application, the proportional valve wet PTO control circuit provided in this application further includes: a Zener diode Z2, the anode of the Zener diode Z2 being grounded, and the cathode of the Zener diode Z2 being connected to the first end of the resistor R2.

[0037] Specifically, the Zener diode Z2 is a TVS diode, model SMCJ36A.

[0038] In this embodiment of the application, the proportional valve wet PTO control circuit provided in this application further includes: a Zener diode Z3, the cathode of the Zener diode Z3 being connected to the negative terminal of the capacitor C5, and the anode of the Zener diode Z3 being grounded.

[0039] Specifically, the Zener diode Z3 has the model number BZT52C03.

[0040] In this embodiment of the application, the proportional valve wet PTO control circuit provided in this application further includes: a diode D2, the two ends of which are respectively connected to the two ends of the voltage-bearing resistor.

[0041] Specifically, the diode D2 is model number IN4148.

[0042] In the embodiments of this application, the resistors R1, R2, R6, and R5 are variable resistors of 1 kΩ.

[0043] The proportional valve wet PTO control circuit provided in this application has fewer components and lower cost; it is built with analog and digital chips, resulting in high reliability; it features simple and convenient switch control; and its timing is adjustable, providing good matching performance.

[0044] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0045] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A proportional valve wet PTO control circuit, characterized in that, include: The system includes a power-on switch J1, transistors Q1 and Q2, Zener diodes Z1 and Z3, resistors R1, R2, R3, R4, R5, R6, and R7, capacitors C3, C4, and C5, a voltage regulator U1, an OR gate U2, a voltage regulator U3, an amplifier U4, an amplifier U5, and a diode D1. Pin 1 of the power-on switch J1 is grounded, and pin 2 is connected to pin 2 of transistor Q1. Pin 1 is connected to the first terminal of resistor R3, and the second terminal of resistor R3 is grounded. Pin 3 of transistor Q1 is connected to the first terminals of resistors R1 and R2, as well as pin 1 of voltage regulators U1 and U3. Pin 4 of voltage regulators U1 and U3 is grounded. Pin 3 of voltage regulator U3 is connected to the VCC terminal of amplifier U4. The second terminal of resistor R2 is connected to the positive terminal of capacitor C3 and amplifier U4. The positive input terminal of the amplifier is connected to the positive input terminal of the amplifier. The second terminal of the resistor R1 is connected to the first terminal of the resistor R7 and the negative input terminal of the amplifier U4. The negative terminal of the capacitor C3 is connected to the second terminal of the resistor R7, the VDD terminal of the amplifier U4 and the negative terminal of the capacitor C5. The output terminal of the amplifier U4 is connected to the first terminal of the resistor R6, the first input terminal of the OR gate U2 and the anode of the diode D1. The cathode of the diode D1 is connected to the first terminal of the resistor R5, the anode of the capacitor C4 and the positive input terminal of the amplifier U5. The third pin of the voltage regulator U1 is connected to the second pin of the transistor Q2 and the VCC pin of the amplifier U5. The first terminal of the resistor R4 is connected to the output terminal of the OR gate U2 and the first pin of the transistor Q2. The negative input terminal of the amplifier U5 is connected to its own output terminal. The output terminal of the amplifier U5 is grounded through the voltage-bearing resistor. The VDD terminal of the amplifier U5 is grounded. The control circuit further includes: a capacitor C1, the positive terminal of which is connected to the first end of the resistor R2, and the negative terminal of which is grounded; The control circuit further includes: capacitor C2, the positive terminal of capacitor C2 is connected to the first end of resistor R2, and the negative terminal of capacitor C2 is grounded; The control circuit further includes: a Zener diode Z2, the anode of which is grounded and the cathode of which is connected to the first end of the resistor R2; The control circuit further includes: a Zener diode Z3, the cathode of which is connected to the negative terminal of the capacitor C5, and the anode of which is grounded; The control circuit further includes a diode D2, the two ends of which are respectively connected to the two ends of the voltage-bearing resistor; The resistor R1 is a sliding rheostat, the resistor R2 is a sliding rheostat, the resistor R5 is a sliding rheostat, and the resistor R6 is a sliding rheostat.

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