1, so you can flexibly change the logic level of the output pulse by selecting the logic current and external resistance to adapt to different logic circuits such as TTL, DTL and CMOS. The LM331 can be powered by a dual or single power supply, can operate between 0 and 40V, the output can be up to 40V, and can prevent Vcc short circuit.
2, is the United States NS company productionThe performance price is higher than the integrated chip. The LM331 can be used as precision frequency voltage (F/V) converters, A/D converters, linear frequency modulation and demodulation, long time integrators, and other related devices. The LM331 is a dual-in-line 8-pin chip that uses a new temperature-compensated band-gap reference circuit for high accuracy over the entire operating temperature range and at supply voltages as low as 0V.
3, if the input voltage signal does not change, then it should be replaced with a high stability, small temperature coefficient of the resistance capacitor timing device. If we move the board, we need to check the solder joints.
1, LM2917 and LM2907 is basically the same, the difference is: LM2917 has a voltage regulator inside, used to improve the stability of the power supply.
2, the problem is that you use the LM2907 circuit and the chip chooses LM2917, when the LM2917 is Vcc5V, there must be a series of resistance between pin 9 and the power supply, which is the reason why your chip continues to heat up.
When the output frequency of 02% full degree is 100KHz, the nonlinear degree value: 0.005% When the output frequency of full degree is 1MHz, the typical value of nonlinear degree: 0.07%.
STM32F103 series chips, the maximum operating frequency can be up to 72M, using 8M external crystal oscillator, generally also need to use the internal PLL phase-locked loop for frequency doubling, compared to the internal 8M RC oscillation.
VFC320 1MHz VFC32 500KHz NJM4151 100KHz TC9400/9401/9402 100KHz LM2907/2917 10K can be measured with a digital circuit after the frequency division (may need to enlarge shaping), you can use a lower speed F-V. If a 74HC74 two-stage frequency division is used, 60KHz is reduced to 15KHz.
The figure is the voltage/frequency conversion circuit composed of NE555. In the circuit, n, A1 and A2 constitute the in-phase integrator, VT1 and A3 constitute the constant current source, and NE555 constitute the monostable multivibrator. The VT2 is controlled by the NE555 to make its switches work against constant currentThe source is on/off controlled. A1 and A2 constitute in-phase integrators, that is, if the in-phase input potential is higher, the output rises. On the contrary, if the in-phase input potential is lower, the output decreases.
The chip models are TPS6108SGM4151 and so on. The TPS61085 is a high efficiency boost converter with input voltage range of 5V to 12V, output voltage range of 8V to 15V, and maximum output current of 2A, with low power consumption, high efficiency and stabilityThe output characteristics of. The SGM4151 chip is a highly efficient power management chip for portable devices and low-power applications in battery-powered devices.
Also to the frequency voltage conversion chip you recommend LM2576 is a five-pin power chip, LM2576 series includes LM2576 (maximum input voltage 40V) and LM2576HV (maximum input voltage 60V) two series. All series of products are available in 3V (-3), 5V (-0), 12V (-12), 15V (-15)And adjustable (-ADJ) and other voltage grade products. In addition, the chip also provides the frequency voltage conversion chip the operating state of the external control pin.
Conversion step-down. LTH7 patch 5-pin charging chip, LTH7 is a single lithium battery charging circuit chip, responsible for the USB port 5V power supply, conversion step-down suitable for 3.7V lithium battery charging. The 5-pin charging chip provides an LED indicator when it is converted to charge, indicating the control system that the charge is long on and full of lights out, and has a battery voltage monitoring circuit to monitor the battery voltage in real time.Stop charging when full.
MP1470 - This model is available in a single-row five-pin package with an efficient buck converter and thermal shutdown protection. MP2459 - This model is available in a dual-in-line 8-pin package, similar to the MP1470, but with a higher output current and a wider input voltage range. LM2675 - This model is available in a dual-in-line 8-pin package with an efficient buck converter and current limiting.
Positive power supply. Single row 5-pin SIP-5H package, single 5W audio power amplifier, power supply voltage range =5 ~ 22V, maximum outputInput voltage =24V, maximum output current =3A, output power =5W, allowable power consumption =5W, operating temperature =-25 ~ 75℃, storage temperature =-40 ~ 150℃.
Voltage frequency conversion V/F chip, LM33 can also be turned with 555, accuracy is not good.
LM331 is the United States NS company produced frequency voltage conversion chip performance price is relatively high frequency voltage conversionThe integrated chip of the change chip can be used as A precision frequency voltage converter, A/ D converter, linear frequency modem and demodulation, long time integrator and its frequency voltage conversion chip other related devices. The LM331 features a new temperature-compensated band-gap reference circuit with a frequency-voltage conversion chip for high accuracy over the entire operating temperature range and at supply voltages as low as 0V.
The solar street lamp controller needs to reasonably control the charge and discharge of the battery, that is, it needs to be storedBattery, solar panel voltage sampling. To this end, the AT89S52 microcontroller needs an external A/D conversion module to convert the voltage into digital signal, and the system uses v/F conversion chip LM331 to compose the digital-to-analog conversion circuit.
This book comprehensively introduces MCS-51 as the core, covering the composition principle of single-chip microcomputer, instruction system, assembly language design, interrupt system, I/O interface, and A/D and D/A interface. The design of single-chip microcomputer application system is emphasized. There are 10 chapters in the book, Chapter 1 is for students to study by themselves, chapters 2 to 9 are the focus of teaching, and chapter 10 can be rootedChoose to explain as needed.
Currently commonly used ASIC, LM33AD654 and VF32, etc., conversion accuracy of more than 0.1% frequency and voltage conversion chip ; But at low frequencies, the switch is useless. Using single chip microcomputer or FPGA, F/D and D/A conversion, the conversion accuracy is between 0.5~0.05%, the range is from 0~2Hz to 0~20KHz, and the reflection time is longer when the frequency is less than 10Hz. For F/V conversion, please refer to the corresponding chip introduction and application materials, this article is notTo repeat.
1, Mitsubishi inverter is the use of power semiconductor devices on and off action to convert the power frequency power supply to another frequency power control device. This article will delve into the working principle of Mitsubishi inverter frequency and voltage conversion chip to help readers better understand the device frequency and voltage conversion chip . Rectifier part The rectifier part is a three-phase bridge type uncontrollable rectifier, the power frequency AC power supply through the wholeConverter to DC power supply. Intermediate DC link The intermediate DC link is filtering, DC energy storage and reactive power buffering.
2, Mitsubishi inverter working principle The main circuit is to provide voltage regulation frequency modulation power supply to the asynchronous motor power conversion part, the main circuit of the inverter can be divided into two categories [1] frequency voltage conversion chip : The voltage type is the inverter that converts the DC of the voltage source into AC, and the filter of the DC circuit is the capacitor. The current mode is a converter that converts the DC of the current source into AC, and the DC loop filter is the inductor.
3,In addition, the inverter is equipped with a torque control mode, even in the speed control mode, it is easy to apply the torque limiting function to ensure the stability and safety of the equipment. This allows the device to achieve high precision at the servo locking level when conducting speed control, whether it is fast response or precise lead speed control. Chapter 2 describes the working principle of the inverter in detail, including its basic structure, control mode, such as U/f control, slip frequency control, etc., and describes the characteristics and use of Mitsubishi FR-A540 inverter, including terminal diagram, operation panel and various modes of control workI can.