阅读说明：本技术 一种高精度机载传感器用正弦波发生器 (Sine wave generator for high-precision airborne sensor ) 是由 梁丁 樊平 彭俊新 程文 于 2020-12-31 设计创作，主要内容包括：本发明提供一种高精度机载传感器用正弦波发生器,所述正弦波发生器包括有高端电压转换部分(AC-TO-DC-H)、低端电压转换部分(AC-TO-DC-L)、辅助供电部分(AUX-POWER)、MCU部分、正弦波产生部分(DDS-SINE-WAVE)、有效值转换部分(AC-TO-RMS),本方案通过数字电路实现的正弦波发生器,其频率变化范围在±1Hz之间,由于采用数字芯片生成正弦波,其性能不会随时间变化而变化,且不需要大体积的电容,整个模块的尺寸和重量都减小一半。(The invention provides a SINE WAVE generator for a high-precision airborne sensor, which comprises a high-end voltage conversion part (AC _ TO _ DC _ H), a low-end voltage conversion part (AC _ TO _ DC _ L), an auxiliary POWER supply part (AUX _ POWER), an MCU part, a SINE WAVE generation part (DDS _ SINE _ WAVE) and an effective value conversion part (AC _ TO _ RMS).)

1. The utility model provides a sine wave generator for high accuracy airborne sensor which characterized in that: the SINE WAVE generator includes a high-side voltage converting part (AC _ TO _ DC _ H), a low-side voltage converting part (AC _ TO _ DC _ L), an auxiliary POWER supplying part (AUX _ POWER), an MCU part, a SINE WAVE generating part (DDS _ SINE _ WAVE), and an effective value converting part (AC _ TO _ RMS), wherein,

the high-end voltage conversion part (AC _ TO _ DC _ H) is used for inputting a high-end signal, the high-end signal is sent TO U6 through an emitter follower of U5, and U6 outputs LEPDAL _ SENSOR _ H _ AD after conversion;

the low-side voltage conversion part (AC _ TO _ DC _ L) is used as a low-side signal input and is sent TO U4 through an emitter follower of U8, and U4 outputs LEPDAL _ SENSOR _ L _ AD after conversion;

an auxiliary POWER supply part (AUX _ POWER) inputs +/-15V of a POWER supply, filters the POWER supply to U2 through C30 and C31, converts the POWER supply into positive and negative VCC and uses the VCC for a rear end;

the MCU part adopts a QFN packaging chip with 28 pins and is provided with an internal crystal oscillator, AD sampling and DA output at the same time;

a SINE WAVE generation part (DDS _ SINE _ WAVE) transmits parameters to a DDS chip in an SPI communication mode, and the DDS generates voltage with corresponding frequency (1800 HZ) and amplitude and outputs the voltage after the voltage is amplified by U10A and U12A;

the AC output voltage J2-1 of the effective value conversion part (AC _ TO _ RMS) is converted into a DC voltage by an RMS conversion chip U1 and is sent TO the MCU for closed-loop control.

Technical Field

The invention relates to the technical field of digital circuits, in particular to a sine wave generator for a high-precision airborne sensor.

Background

The existing airborne sensor is realized by an analog circuit adopted by a sine wave generator, namely, a triode, a resistor, a capacitor and an operational amplifier generate sine waves, the frequency fluctuation range of the sine waves is large and ranges from-150 Hz to 150Hz, and the performance of the resistor and the capacitor is reduced along with the longer service time, so that the voltage and frequency precision of the sine waves are influenced. Meanwhile, the analog circuit has the defects of large capacitance volume, and large size and weight of the whole module.

Disclosure of Invention

The invention aims to provide a sine wave generator for a high-precision airborne sensor, which is reasonable in structure and good in using effect.

In order to achieve the purpose, the technical scheme provided by the invention is as follows: a SINE WAVE generator for a high-precision airborne sensor comprises a high-end voltage conversion part (AC _ TO _ DC _ H), a low-end voltage conversion part (AC _ TO _ DC _ L), an auxiliary POWER supply part (AUX _ POWER), an MCU part, a SINE WAVE generation part (DDS _ SINE _ WAVE) and an effective value conversion part (AC _ TO _ RMS),

the high-end voltage conversion part (AC _ TO _ DC _ H) is used for inputting a high-end signal, the high-end signal is sent TO U6 through an emitter follower of U5, and U6 outputs LEPDAL _ SENSOR _ H _ AD after conversion;

the low-side voltage conversion part (AC _ TO _ DC _ L) is used as a low-side signal input and is sent TO U4 through an emitter follower of U8, and U4 outputs LEPDAL _ SENSOR _ L _ AD after conversion;

an auxiliary POWER supply part (AUX _ POWER) inputs +/-15V of a POWER supply, filters the POWER supply to U2 through C30 and C31, converts the POWER supply into positive and negative VCC and uses the VCC for a rear end;

the MCU part adopts a QFN packaging chip with 28 pins and is provided with an internal crystal oscillator, AD sampling and DA output at the same time;

a SINE WAVE generation part (DDS _ SINE _ WAVE) transmits parameters to a DDS chip in an SPI communication mode, and the DDS generates voltage with corresponding frequency (1800 HZ) and amplitude and outputs the voltage after the voltage is amplified by U10A and U12A;

the AC output voltage J2-1 of the effective value conversion part (AC _ TO _ RMS) is converted into a DC voltage by an RMS conversion chip U1 and is sent TO the MCU for closed-loop control.

The technical advantages of the invention are as follows:

1) sampling an effective value of the alternating voltage: there are two AC5V paths, the input AC signal is converted into effective value DC5V of DC signal, the high-order input of the sensor corresponds to the high-order output, the low-order input of the sensor corresponds to the low-order output, and the output signal/input signal range is + -1%.

2) Generating a sine voltage: the DC +/-15V obtains a 1800HZ square wave through a push-pull circuit of two triodes, generates a sine wave through a capacitor, and outputs the sine wave after being amplified through an operational amplifier. The output frequency of the device is greatly different due to different device performances, and the consistency of the product is poor; and the output amplitude is greatly changed at the high temperature of 70 ℃ and the low temperature of-55 ℃ due to different device performances.

Drawings

Fig. 1 is a schematic framework diagram of the present invention.

Fig. 2 is a schematic diagram of the high-side voltage converting part of the present invention.

FIG. 3 is a schematic diagram of a low-side voltage conversion circuit according to the present invention.

Fig. 4 is a schematic circuit diagram of the auxiliary power supply portion of the present invention.

FIG. 5 is a schematic diagram of a circuit of the MCU part of the present invention.

Fig. 6 is a schematic diagram of a sine wave generating part of the circuit of the present invention.

FIG. 7 is a schematic circuit diagram of the effective value converting part of the present invention.

Detailed Description

The invention will be further described with reference to the accompanying drawings, in which preferred embodiments of the invention are: referring TO fig. 1 TO 7, the SINE WAVE generator for the high-precision on-board sensor according TO the present embodiment includes a high-end voltage converting part (AC _ TO _ DC _ H), a low-end voltage converting part (AC _ TO _ DC _ L), an auxiliary POWER supplying part (AUX _ POWER), an MCU part, a SINE WAVE generating part (DDS _ SINE _ WAVE), and an effective value converting part (AC _ TO _ RMS), wherein,

the high-side voltage conversion part (AC _ TO _ DC _ H) is a high-side signal input, and is sent TO U6 (valid value conversion chip AD536) through an emitter follower of U5 (operational amplifier LM2904), and U6 is converted into a corresponding direct-current voltage and then is output TO led al _ SENSOR _ H _ AD (this is a terminal number);

r17, R16 and U5 in the AC _ TO _ DC _ H form a high-end signal input filtering and buffering part, and the high-end signal input filtering and buffering part is isolated by C7 (a capacitor of 25V/1 uF) and then is transmitted TO U6 (an effective value conversion chip AD 536);

the low-side voltage conversion part (AC _ TO _ DC _ L) is a low-side signal input and is sent TO U4 (an effective value conversion chip AD536) through an emitter follower of U8, and U4 (the effective value conversion chip AD536) is converted TO output LEPDAL _ SENSOR _ L _ AD (a terminal number);

r21, R20 and U8 in the AC _ TO _ DC _ L form a low-end signal input filtering and buffering part, and the low-end signal input filtering and buffering part is isolated by C10 (a capacitor of 25V/1 uF) and then is transmitted TO U4 (an effective value conversion chip AD 536);

an auxiliary POWER supply part (AUX _ POWER) inputs +/-15V of a POWER supply, filters the POWER supply through C30 (a capacitor of 25V/4.7 uF) and C31 (a capacitor of 25V/4.7 uF) to U2 (a POWER supply conversion chip LT 3032), converts the POWER supply into positive and negative VCC and uses the VCC for a rear end;

the MCU part adopts a QFN packaging chip with 28 pins and is provided with an internal crystal oscillator, AD sampling and DA output at the same time;

a SINE WAVE generation part (DDS _ SINE _ WAVE) transmits parameters to a DDS chip in an SPI communication mode, the DDS generates voltage with corresponding frequency (1800 HZ) and amplitude, and the voltage is amplified and followed by a U10A (high-precision operational amplifier OPA 1622) and a U12A (high-precision operational amplifier OPA 1622) and then output to J2-1 (terminal number) and J2-2 (terminal number), wherein R39, R29, R3, R40 and U10A form an amplifying circuit, and R5 and U12A form an emitter follower circuit;

an effective value conversion part (AC _ TO _ RMS) AC input voltage J2-1 (input terminal) is converted into DC voltage through an RMS (effective value conversion) conversion chip U1 (an effective value conversion chip LTC 1966), and the DC voltage is filtered by R15, C42 and R24 and then is sent TO the MCU for closed-loop control.

After the above-mentioned scheme is adopted in the present embodiment,

sampling an effective value of the alternating voltage: there are two AC5V paths, the input AC signal is converted into effective value DC5V of DC signal, the high-order input of the sensor corresponds to the high-order output, the low-order input of the sensor corresponds to the low-order output, and the output signal/input signal range is + -1%.

Sinusoidal voltage generation: the DC +/-15V obtains a 1800HZ square wave through a push-pull circuit of two triodes, generates a sine wave through a capacitor, and outputs the sine wave after being amplified through an operational amplifier. The output frequency of the device is greatly different due to different device performances, and the consistency of the product is poor; and the output amplitude is greatly changed at the high temperature of 70 ℃ and the low temperature of-55 ℃ due to different device performances.

The sine wave generator realized by a digital circuit is developed, the frequency variation range is +/-1 Hz, the performance of the sine wave generator cannot be changed along with the time variation due to the fact that a digital chip is adopted to generate sine waves, a large-size capacitor is not needed, and the size and the weight of the whole module are reduced by half.

The above-mentioned embodiments are merely preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, so that the changes in the shape and principle of the present invention should be covered within the protection scope of the present invention.