PWM (Pulse Width Modulation) control circuit meeting aircraft requirements

Abstract

The utility model discloses a PWM (Pulse Width Modulation) control circuit meeting requirements of an airplane. The PWM control circuit is a pure hardware circuit. The PWM control circuit comprises a potentiometer, a PWM module and the like. The beneficial effects of the PWM control circuit are that the analog voltage of the input power supply is converted into a PWM output signal with exponential growth, the frequency, the precision and the polarity of the PWM output signal are controllable, and the PWM control circuit can be used for control of airborne equipment such as aircraft illumination and the like.

Description

Technical Field

[0001] The utility model relates to an electronic circuit, in particular to a PWM control circuit which meets the requirements of an aircraft. Background Art

[0002] Many airborne devices require PWM control, such as lighting, display devices, and temperature control devices that use LEDs as light sources. The advantages of PWM control are: high output accuracy and little effect on LED color drift, so it is widely used. The disadvantage of PWM control is that it often requires the use of specialized software or programmable complex hardware to achieve the output of PWM control signals, resulting in high cost and complex hardware circuits, and reduced reliability.

[0003] At present, some manufacturers use analog voltage control instead of PWM control for airborne equipment with simple working principles. However, analog voltage control is prone to problems such as anti-electromagnetic interference, and it is difficult to achieve exponentially regulated output in the analog voltage control method, which is not conducive to human-machine ergonomics. Summary of the invention

[0004] The purpose of the utility model is to solve the problem that the PWM control circuit in the prior art requires software intervention, and to provide a PWM control circuit that meets the requirements of aircraft.

[0005] In order to achieve the above-mentioned purpose of the utility model, the utility model provides a technical solution: a PWM control circuit that meets the requirements of the aircraft, including: a potentiometer, a PWM module. The PWM module uses LTC6992, the first non-common end of the potentiometer is connected to the power supply end, the second non-common end of the potentiometer is grounded, the common end of the potentiometer is respectively connected to the negative end of the TVS tube D9, the first end of the capacitor C4 and the first end of the resistor R6, the positive end of the TVS tube D9 is grounded, the second end of the capacitor C4 is grounded, the second end of the resistor R6 is respectively connected to the first end of the resistor R21 and the first end of the resistor R22, the second end of the resistor R22 is respectively connected to the first end of the resistor R21, the first end of the capacitor C11, and the 1st pin of the PWM module, the second end of the resistor R23 is grounded, the second end of the capacitor C11 is grounded, the 2nd pin of the PWM module is grounded, and the 3rd pin of the PWM module is grounded. The first pin of the PWM module is connected to the first end of the resistor R18, the second end of the resistor R18 is connected to the ground, the 4th pin of the PWM module is respectively connected to the first end of the resistor R33 and the first end of the resistor R34, the 5th pin of the PWM module is respectively connected to the first end of the capacitor C12, the second end of the resistor R33 and the reference voltage end, the second end of the capacitor C12 is connected to the ground, the second end of the resistor R34 is connected to the ground, the 6th pin of the PWM module is connected to the first end of the resistor R30, the second end of the resistor R30 is respectively connected to the first end of the resistor R29 and the G end of the P-channel MOS tube Q4, the second end of the resistor R29 is connected to the ground, the S end of the MOS tube Q4 is connected to the ground, and the D end of the MOS tube Q4 is used to provide a PWM output signal to the LED.

[0006] As a preferred solution of the PWM control circuit, the first non-common end of the potentiometer is further connected to the negative end of the TVS tube D6 and the first end of the capacitor C1 respectively, the positive end of the TVS tube D6 is grounded, and the second end of the capacitor C1 is grounded.

[0007] As a preferred solution of the PWM control circuit, the second non-common end of the potentiometer is further connected to the negative end of the TVS tube D7 and the first end of the capacitor C3 respectively, the positive end of the TVS tube D7 is grounded, and the second end of the capacitor C3 is grounded.

[0008] Compared with the prior art, the beneficial effects of the utility model are at least that: the PWM control circuit is a pure hardware circuit, which realizes the conversion of the analog voltage of the input power supply into a PWM output signal with a quasi-exponential growth, and the frequency, accuracy and polarity of the PWM output signal are controllable, and can be used to control airborne equipment such as aircraft lighting. Through TVS tubes, resistors, etc., the circuit is prevented from being damaged by instantaneous high voltage or high current generated by static electricity, lightning, etc.; the requirements of aircraft ergonomics are met, and while ensuring the performance of various functions, the design complexity of the product is reduced, the volume is reduced, the weight is reduced, the cost is reduced, and the reliability is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a circuit structure diagram of the utility model. DETAILED DESCRIPTION

[0010] The present invention is further described in detail below through specific implementations in combination with the accompanying drawings. It should be noted that the description of these implementations is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each implementation of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0011] See also Figure 1 , the figure shows a PWM control circuit that meets the requirements of the aircraft. The PWM control circuit is a pure hardware circuit. The PWM control circuit includes: a potentiometer U1, a PWM module U2, etc.

[0012] The PWM module U2 uses LTC6992. Pin 1 of the PWM module U2 is the potentiometer analog voltage input pin. Pin 2 of the PWM module U2 is the ground pin. Pin 3 of the PWM module U2 is the PWM output signal frequency adjustment pin. Pin 4 of the PWM module U2 is used to receive the external V SET Voltage signal. Pin 5 of PWM module U2 is the power supply pin. Pin 6 of PWM module is used to provide PWM output signal.

[0013] The first non-common terminal of the potentiometer U1 is connected to the power supply terminal. The second non-common terminal of the potentiometer U1 is connected to the ground terminal. The common terminal of the potentiometer U1 is connected to the negative terminal of the TVS tube D9, the first terminal of the capacitor C4 and the first terminal of the resistor R6 respectively. The positive terminal of the TVS tube D9 is connected to the ground terminal. The second terminal of the capacitor C4 is connected to the ground terminal. The second terminal of the resistor R6 is connected to the first terminal of the resistor R21 and the first terminal of the resistor R22 respectively. The second terminal of the resistor R22 is connected to the first terminal of the resistor R21, the first terminal of the capacitor C11 and the pin 1 of the PWM module respectively. The second terminal of the resistor R23 is connected to the ground terminal. The second terminal of the capacitor C11 is connected to the ground terminal. The pin 2 of the PWM module is connected to the ground terminal. The pin 3 of the PWM module is connected to the first terminal of the resistor R18. The second terminal of the resistor R18 is connected to the ground terminal. The pin 4 of the PWM module is connected to the first terminal of the resistor R33 and the first terminal of the resistor R34 respectively. The pin 5 of the PWM module is connected to the first terminal of the capacitor C12, the second terminal of the resistor R33 and the reference voltage terminal respectively. The second terminal of the capacitor C12 is connected to the ground terminal. The second terminal of the resistor R34 is connected to the ground terminal. The 6th pin of the PWM module is connected to the first end of the resistor R30. The second end of the resistor R30 is respectively connected to the first end of the resistor R29 and the G end of the P-channel MOS tube Q4. The second end of the resistor R29 is connected to the ground. The S end of the MOS tube Q4 is connected to the ground. The D end of the MOS tube Q4 is used to provide a PWM output signal to the LED.

[0014] Preferably, the first non-common terminal of the potentiometer U1 is further connected to the negative terminal of the TVS tube D6 and the first terminal of the capacitor C1 respectively. The positive terminal of the TVS tube D6 is connected to the ground terminal. The second terminal of the capacitor C1 is connected to the ground terminal.

[0015] Preferably, the second non-common terminal of the potentiometer U1 is further connected to the negative terminal of the TVS tube D7 and the first terminal of the capacitor C3 respectively. The positive terminal of the TVS tube D7 is connected to the ground. The second terminal of the capacitor C3 is connected to the ground.

[0016] The duty cycle of the PWM output signal can be adjusted by changing the output voltage of the common terminal of the potentiometer.

[0017] The purpose of configuring the resistor R21 is to make the PWM output signal change in a quasi-exponential manner to meet the requirements of ergonomics.

[0018] The purpose of configuring the resistors R22 and R23 is to divide the output voltage of the common terminal of the potentiometer.

[0019] The purpose of configuring resistor R18 is to set V SET The size of the voltage signal can adjust the frequency of the PWM output signal.

[0020] The purpose of configuring resistors R33 and R34 is to set V DIV The size of the voltage signal can adjust the accuracy and polarity of the PWM output signal.

[0021] The purpose of configuring the magnetic bead FB1 and the capacitor C25 is to filter out the ripple and noise of the reference voltage of the chip U8.

[0022] The purpose of configuring the TVS tube D6 and the capacitor C1 is to form an input protection circuit for the first non-common end of the potentiometer.

[0023] The purpose of configuring the TVS tube D7 and the capacitor C3 is to form an input protection circuit for the second non-common end of the potentiometer.

[0024] The purpose of configuring the TVS tube D9 is to prevent static electricity, lightning and other instantaneous high voltages or high currents from damaging the circuit.

[0025] The above only expresses the implementation mode of the utility model, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A PWM control circuit that meets aircraft requirements, characterized in that: include: Potentiometer, PWM module, PWM module uses LTC6992, the first non-common end of the potentiometer is connected to the power supply end, the second non-common end of the potentiometer is grounded, the common end of the potentiometer is respectively connected to the negative end of TVS tube D9, the first end of capacitor C4 and the first end of resistor R6, the positive end of TVS tube D9 is grounded, the second end of capacitor C4 is grounded, the second end of resistor R6 is respectively connected to the first end of resistor R21 and the first end of resistor R22, the second end of resistor R22 is respectively connected to the first end of resistor R21, the first end of capacitor C11, and pin 1 of the PWM module, the second end of resistor R23 is grounded, the second end of capacitor C11 is grounded, and pin 2 of the PWM module is grounded, PW Pin 3 of the M module is connected to the first end of resistor R18, the second end of resistor R18 is connected to the ground, pin 4 of the PWM module is respectively connected to the first end of resistor R33 and the first end of resistor R34, pin 5 of the PWM module is respectively connected to the first end of capacitor C12, the second end of resistor R33 and the reference voltage end, the second end of capacitor C12 is connected to the ground, the second end of resistor R34 is connected to the ground, pin 6 of the PWM module is connected to the first end of resistor R30, the second end of resistor R30 is respectively connected to the first end of resistor R29 and the G end of P-channel MOS tube Q4, the second end of resistor R29 is connected to the ground, the S end of MOS tube Q4 is connected to the ground, and the D end of MOS tube Q4 is used to provide PWM output signal to the LED.

2. The PWM control circuit according to claim 1, characterized in that: The first non-common end of the potentiometer is further connected to the negative end of the TVS tube D6 and the first end of the capacitor C1 respectively, the positive end of the TVS tube D6 is connected to the ground, and the second end of the capacitor C1 is connected to the ground.

3. The PWM control circuit according to claim 1, characterized in that: The second non-common end of the potentiometer is further connected to the negative end of the TVS tube D7 and the first end of the capacitor C3 respectively, the positive end of the TVS tube D7 is connected to the ground, and the second end of the capacitor C3 is connected to the ground.

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