The general-purpose integrated operational amplifier LM324 has four operational amplifiers, and a power supply tester can be made by using two of them. This tester is especially suitable for the inspection of mass-produced power supply boards on the factory production line. Just look at the indicator lights to determine the quality of the power supply board.
Switch Mode Power Supply (SMPS), also known as switching power supply and switching converter, is a high-frequency power conversion device and a type of power supply. Its function is to convert a level of voltage into the voltage or current required by the user through different forms of architecture. The input of the switching power supply is mostly AC power (such as commercial power) or DC power, and the output is mostly equipment that requires DC power, such as a personal computer, and the switching power supply converts the voltage and current between the two. This article introduces the switching power supply scheme composed of LM324.
The LM324 is a quad op amp and is a big class. Depending on its suffix, there are also A-seed models (specifications). Regarding the difference between LM324ad and LM324, we can distinguish them from their performance parameters. This article discusses the difference between LM324ad and LM324, and whether they can be replaced with each other in the circuit. There are differences with other models, such as: LM741, LM358, LM318 and so on.
Because the LM324 quad-op amp circuit has the advantages of wide power supply voltage range, low static power consumption, single power supply and low price, it is widely used in various circuits.
The LM324 quad-op amp circuit has the advantages of wide power supply voltage range, low static power consumption, single power supply and low price, so it is widely used in various circuits. This article will introduce the connection and detection methods of the positive and negative power supplies of the LM324.
The self-made charger uses 4 operational amplifiers of LM324 as comparators, uses TL431 to set the voltage reference, and uses S8550 as adjustment tube to step down the input voltage and charge the battery. It is characterized by simple circuit, reliable operation, no adjustment, and components easy to buy, etc.
This paper summarizes the design and debugging methods of analog-to-digital conversion interface circuit based on ADC0809. It is concluded that the analog-to-digital conversion ADC is an important part of the microcomputer measurement and control system.
The LM339 (four-way differential comparator) is equipped with four independent voltage comparators inside the voltage comparator chip. It is a common integrated circuit and is mainly used in high-voltage digital logic gate circuits. Various voltage comparator circuits and oscillator circuits can be easily formed by using lm339.
The LM339 integrated block houses four independent voltage comparators designed to provide transistor grounds that saturate in the presence of an input signal within the passband. It adopts C-14 type package. Figure 1 shows the appearance and pin arrangement. Because LM339 is flexible and widely used, major IC manufacturers and companies in the world have launched their own quad comparators, such as IR2339, ANI339, SF339, etc. Their parameters are basically the same and can be used interchangeably.
The LM339N is a four-way voltage comparator, using a dual-in-line 14-pin package, the maximum operating voltage is ±18V, and the power consumption is 265mW. It is used in induction cookers and other products. Compatible or substitute reference models: LM339, IR2339, μA339PC, μPC339C, TA75339. This article presents an instrumentation circuit designed with the LM339N.
Due to insufficient water supply in some units and living areas, it is necessary to store water in the reservoir first, and then supply water in a regular manner. In this way, the pump worker must know the water level of the reservoir at any time in the pump room (generally, the reservoir is more than ten meters away from the pump room). In the past, electrodes such as copper rods or stainless steel were used to detect the water level of the pool, but the function of the electrodes was lost shortly after use due to electrical corrosion. Therefore, this paper introduces a method of using LM339 voltage comparator to make a water level gauge in a reservoir. The design performs signal processing according to the water level, controls the potential of the input terminals of multiple voltage comparators, and makes the output terminals have corresponding changes, so as to Drive different LED light-emitting tubes to achieve the effect of displaying the water level.
LM339N is a four-op-amp IC, which can be used for signal voltage amplification, comparison, logic op-amp, and also for protection. LM339 is a four-voltage comparator mainly used in detection circuits and reference voltages. It is mostly used in the detection circuit of induction cookers, etc., changing its The structure and component parameters of peripheral circuits can be used for various purposes.
LM339 (four-way differential comparator) is equipped with four independent voltage comparators inside the voltage comparator chip. It is a common integrated circuit and is mainly used in high-voltage digital logic gate circuits. Various voltage comparator circuits and oscillator circuits can be easily formed by using lm339.
The function of the LM393 is that the output load resistance can be connected to any power supply voltage within the allowable power supply voltage range, and is not limited by the voltage value of the Vcc terminal. This output can be used as a simple SPS open circuit to ground (when no load resistor is used), and the sink current in the output section is limited by the available drive and device β values. When the limit current (16mA) is reached, the output transistor will exit and the output voltage will rise quickly.
There are 2 independent high-precision voltage comparators in the LM393, and its bias voltage can be as low as 2.0mV. Use a single power supply to supply a wide range of voltages. The advantages are: high-precision comparator; can reduce the VOS drift of a single temperature; no dual power supply; all use a consistent logic format.
The LM393 is a low-power, low-offset voltage two-comparator, and the LM339 is a low-power, low-offset voltage four-comparator. and LM358 is a dual operational amplifier, which cannot be directly replaced. However, in some circuits that require less precision, the operational amplifier can be used as a voltage comparator, but the operational amplifier cannot be used for comparison. Because there is no amplification function, the pull-up resistor of the original 393 output should be removed when 358 is replaced by 393.
ADC0809, as a successive comparison A/D converter, is moderate in accuracy, speed and price, and is the most commonly used A/D converter. In the interface circuit with the microcontroller, the key is to clarify the principle of 0809 conversion and the working process of the microcontroller to control the 0809, and there are certain requirements for software programming.
The digital voltmeter designed based on ADC0809 realizes the function of collecting 8 channels of data and displaying the results on a four-in-one digital tube in a rolling display or individually. The minimum resolution of the measurement is 0.019V; the digital voltmeter has a simple circuit. , low cost and other advantages, it can easily measure the amount of 8-channel A/D conversion, and can choose different working modes of scrolling display on the digital tube or single-channel display.
ADC0809 is one of the most frequently used digital-to-analog conversion chips in this type of microcontroller data acquisition system. However, in many literatures introducing ADC0809 chip, the digital-to-analog conversion chip often needs more auxiliary chips when used, the hardware circuit and software writing are complicated, and the corresponding cost is high. Therefore, this paper presents a method that requires only two ADC0809 digital-to-analog conversion chips and one 741s74 flip-flop chip to achieve simple, fast and accurate 16-channel real-time data acquisition.
The hardware implementation method of the multi-channel data acquisition system based on AD0809 and single-chip microcomputer adopts 8051 single-chip microcomputer as the core in the terminal to control the data acquisition and data uploading, and converts the 0-5V DC voltage into a computer that can be processed by the MD converter. The digital signal is then processed by the single-chip microcomputer, so as to complete the functions of displaying on the terminal and uploading the data. The upper computer in the system completes the functions of displaying the collected data and controlling the lower computer.
Because the automatic flow detection system of ADC0809 selects 8-channel 8-bit A/D converters ADC 0809 and 8031 single-chip microcomputer with 8-channel analog channel selection switch and control logic compatible with microprocessor as microprocessors, so It has the characteristics of simple structure, reliable performance, stable operation and low cost. The system can also be used to detect pressure or temperature if the flow sensor is replaced by a pressure sensor or a temperature sensor
The LM2596 series switching voltage regulators are step-down power management monolithic integrated circuits that can output a drive current of 3A and have good linear and load regulation characteristics. This voltage regulator can be used by adding a few external components. The device integrates frequency compensation and a fixed frequency generator. The switching frequency is 150KHz, and compared with the low frequency switching regulator, the filter element of smaller size can be used. This article will introduce the application circuit of LM2596.
At present, there are more and more consumer electronic products, such as smart phones, tablet computers, PSP game consoles and other electronic products, which provide great convenience to people’s life, work and entertainment. However, these electronic products have a common disadvantage that the capacity of their own lithium batteries is limited, and our electronic products are often unusable due to the lack of electricity. In order to solve the problem of battery life for electronic products, this paper designs a circuit that integrates charging and discharging of lithium batteries.
As we all know, the ion nitriding process has relatively high requirements for the pressure control in the furnace. Therefore, a gas flow controller based on L298N chip driven DC motor control is designed in this paper, which can be used to control the exhaust gas flow of the reactor.
The boost converter can reduce the output current and the capacitance and volume of the output filter capacitor under a certain output power, and is widely used in switching power supplies and electronic ballasts. Common control methods include voltage feedback control and current feedback control.
Embedded devices work in a real-time environment, so the clock system is needed to record the time of the event, and timely notify the host computer of the collected data and the time of the event in time, so as to take corresponding emergency measures in time…
There are many kinds of integrated A/D converters, and various factors should be considered when selecting integrated chips. Generally, successive comparison type A/D converters are used more, ADC0804 is such a monolithic integrated A/D converter.
With the development of my country’s economy and the in-depth advancement of scientific research, the application of temperature monitoring and control systems in industrial design, intelligent instruments, and daily household appliances has become more and more extensive.
With the rapid development of electronic power technology today, the requirements for the power supply of devices are becoming more and more demanding. Among various types of power supplies, switching power supplies are increasingly used for their stability, high efficiency and high power density.
TDA2822M is a dual audio power amplifier integrated circuit. It is characterized by high efficiency, low power consumption, quiescent operating current of only 6mA, and the power supply voltage can work normally within the range of 1.8V to 15V.
With the development of the semiconductor industry, the applications of switching power supplies are constantly expanding. At the same time, the requirements for switching power supplies are also increasing. High power density, small size, and low price have become the trends in the switching power supply industry.
TDA7294 is a quite innovative DMOS high-power integrated amplifier circuit. It has swept away the raw, cold and hard tones of linear integrated amplifiers and thick film integrated in the past, and is widely used in HI-FI fields: such as home theaters, active speakers, etc.
With the popularity of various personal music players, music has become one of the indispensable elements in our daily life. However, long-term use of headphones to listen to music can cause hearing damage.
TDA2030 is an integrated power amplifier that has been widely used in recent years. It has the characteristics of small size, large output power, low distortion, etc., and has an internal protection circuit.
AT89 series microcontroller is a new type of 8-bit CMOS microcomputer with high performance, low price, low voltage and low power consumption. Its significant advantages are: ① It contains F1ash memory, which can be modified at will during the development of the system.
The 74LS48 chip is a commonly used seven-segment digital tube decoder driver. It is commonly used in the display systems of various digital circuits and microcontroller systems. This article will introduce the pins, truth table, logic functions and common circuits of the 74LS48.
The 74LS192 is a synchronous decimal reversible counter that has dual clock inputs and features such as clear and set. It can be directly cascaded without external circuit, and the two output terminals of borrow and carry can be cascaded to count up and down, which is convenient to use.
Ultrasonic flaw detectors have played a huge role in the detection of internal defects in mechanical parts. The principle is that the voltage excites the ultrasonic transducer to emit ultrasonic waves into the part, and the ultrasonic wave reflected by the defect returns to the transducer and converts it into a voltage.
With the rapid development of modern electronic technology, frequency characteristic tester is an important tool in the field of modern electronic measurement, and its design concept is constantly innovating.
The fiber grating sensor is made by using the mechanism that the reflection center wavelength of the fiber grating is shifted when it is subjected to external physical action.
AD590 is a current output type two-end temperature sensor made by AD company using the relationship between the forward current of the PN junction and the temperature. Due to the good linearity and interchangeability of the device, the measurement accuracy is high and the power supply fluctuations are eliminated.
Heart rate is a key indicator value that reflects physical health. In simple terms, heart rate refers to the frequency of cardiovascular beats in 1 minute. The heart rate test can provide scientific evidence for disease diagnosis, patient care, and player training.
The 74LS244 is a 3-state 8-bit buffer, generally used as a bus driver. The 74LS244 has no latching function. The address latch is a temporary register, which temporarily stores the address code on the bus according to the state of the control signal.
One of the important features of intelligent household appliances is human-computer information interaction. The user understands the working state of the household appliance through visual, auditory and other means, and at the same time controls the work of the appliance through input devices such as buttons.
74LS00 is four groups of 2-input NAND gates (positive logic), a total of 54/7400, 54/74H00, 54/74S00, 54/74LS00.
The displays used in the single-chip application system mainly include LED and LCD. In recent years, it has also been displayed by CRT.
As we all know, low-power linear regulated power supplies are widely used electronic equipment in electronic system testing, but at present, low-power power supplies are mostly fixed voltage output or voltage adjustable, but there is no intuitive digital display, which is inconvenient to operate and use.
For the owners of small oil depots and oil storage tanks such as small and medium-sized gas stations, it is necessary to know the oil storage volume at any time, so as to maintain the basic balance of oil inflow and outflow.
In recent years, with the continuous development of new technologies, batteries as a power source not only play an important role in transportation (railway, subway, ship), power generation, communication, aerospace, chemical industry, traditional automobile and other industries, but also have begun to be used as a power source.
LM311 is a commonly used linear comparator, which is widely used in comparison and shaping circuits, as shown in Figure 1. However, unexpected problems often occur in LM311 applications, that is, the output pulse signal is not as ideal as theoretical analysis…
At present, railway signal lights mainly use double-filament incandescent lamps as light sources, but because of their lifespan, the development of signal lights has always been restricted.
LM1875 is a power amplifier integrated block, it has few peripheral circuits and perfect overload protection function in use. It adopts advanced electronic circuit design technology and process, so it can even have low distortion at high output.
In order to solve the problem of transient distortion, the typical application circuit of the LM3886 power amplifier is changed to a current negative feedback type, and the current sampled through the speaker voice coil is fed back to the input end of the power amplifier with a resistor, and the speaker system is also included in the feedback system.
The uninterruptible DC power supply is a system equipment that connects the battery (mostly lead-acid maintenance-free battery) with the host and converts the DC power into the commercial power through the host inverter and other module circuits.
Due to the problems of complex structure, inaccurate zero-crossing detection and cumbersome programming in the zero-crossing detection circuit of the AC circuit, this paper introduces a zero-crossing detection circuit with a simple hardware structure based on LM339.
Tracking trolley is a trolley that can drive along the preset motion track line, and it is used in many experimental teaching places. In the whole process of the tracking trolley driving, how to make the car drive along the motion track route accurately without big error is the essence of using the tracking trolley.
The paper introduces the signal generator based on four operational amplifiers LM324 with differential input as key components in detail. The design scheme is based on the RC bridge sine wave oscillation circuit to generate a sine wave.
In electronic technology, waveform signals such as square wave and triangular wave are often used to generate power supply circuits, which are often used to generate data signals of various electronic devices, communicate between electronic technologies, and their automatic measurement and control systems and automatic control systems.
LED level indicator (English LED level indicator) can indicate the size of the signal level, on the other hand, it can play a role in decorating and beautifying the panel. The LED level indicator is a level indicator composed of light-emitting diodes.
Temperature condensation controllers are widely used in high and low voltage distribution cabinets, terminal boxes and substations of power electronics to detect changes in ambient temperature and humidity in real time and protect power electronic devices.
The LM358 includes two independent, high-gain, internal frequency compensated dual operational amplifiers, which are suitable for single-supply use with a wide range of power supply voltages, and are also suitable for dual-supply operating modes.
The LM358 is an integrated circuit that integrates two operational amplifiers, so it is called a dual-operation integrated circuit. Its packaging forms include plastic-encapsulated 8-lead dual in-line, SMD and circular metal shell packages. It is widely used in signal amplification and voltage comparison circuits.
Because the LM358 includes two independent, high gain, internal frequency compensated operational amplifiers, it is suitable for single-supply use with a wide supply voltage range, and is also suitable for dual-supply operating modes.
The dual operational amplifier LM358 is suitable for single-supply use with a wide supply voltage range. It is also suitable for dual-supply operation mode. Under the recommended operating conditions, the supply current is independent of the supply voltage.
The LM358 is a dual operational amplifier with a wide range of applications, which has the advantages of low price and wide voltage range. This article will introduce the circuit design composed of LM358.
The LM358 is a dual operational amplifier. It includes two independent, high-gain, internal frequency-compensated operational amplifiers, which are suitable for single-supply use with a wide supply voltage range, as well as dual-supply operating modes.
LM358P is a very high-grade dual operational amplifier circuit with high stability and low price. This chip is composed of two independent high-gain operational amplifiers. It works independently under the condition of dual power supply and has internal frequency compensation.
Breathing lamp is a kind of decorative LED circuit newly produced with digital products, which can be seen on mobile phones, mice, computer cases, home lamps and so on.
Based on the spectrum theory analysis of pulse width modulation (PWM) waveform, in view of the requirement of (±10)V analog signal input required for AC servo motor to realize speed closed-loop control, this paper designs a (±10)V analog signal output based on PWM filtering based on LM358 chip circuit.
In order to prevent data loss caused by sudden power failure in the single-chip microcomputer system, it is generally necessary to store important data in EEPROM. Due to the limited erasing life of EEPROM, it is not advisable to erase it every time the program is executed. This design proposes…
In today’s society, people enjoy the great convenience brought by electronic equipment, but any electronic equipment has a common circuit – power circuit. The requirement of electronic equipment for the power supply circuit is to be able to provide continuous and stable power that meets the load requirements, and usually…
LM386 is a common type of integrated OTL type power amplifier circuit. It is an audio integrated power amplifier. It has the advantages of low power consumption, adjustable internal chain gain, large power supply voltage range, few external components and low total harmonic distortion.
The positive power amplifier integrated circuit LM386 is commonly known as “universal power amplifier circuit” because of its wide application. LM386 has the advantages of low power consumption, wide operating voltage range, few peripheral components, and convenient device adjustment.
LM386 is a low-power audio amplifier integrated circuit. It adopts 8-pin dual-in-line plastic package. The working voltage is 4V-15V. When the power supply voltage is 12V, the output power of 300mW can be obtained on an 8Ω load. Various oscillators can be easily made with LM386.
LM386 is widely used in audio power amplifier circuits. In most occasions or when used alone, LM386 can work normally, but when used in conjunction with other circuits, it may cause self-excitation and reduced sensitivity. This article mainly introduces the prevention measures to deal with this phenomenon and the precautions…
To minimize external components, the voltage gain is built in to 20. But by adding an external resistor and capacitor between pins 1 and 8, the voltage gain can be adjusted to any value up to 200. The input is referenced to status, while the output is automatically biased to…
Pager circuit is composed of a preamplifier stage and LM386 low-power integrated circuit. The circuit is simple, the cost is low, the volume is small, and it is easy to use. It is suitable for beginners to make electronic hobbies. After actual use, the sound is clear…
The development of modern sonar technology began in the 20th century and was initially applied in the military, that is, to detect, classify, locate and track underwater targets, conduct underwater communication and navigation, and ensure the underwater safety of ships. With the rapid development of electronic technology and computer technology…
The operating voltage range of the LM386 power amplifier integrated circuit is wide, the minimum is 4V, and the maximum is 15V. Its static power consumption is only 4mA, and the gain is up to 46dB, or 200 times. Its circuit is simple and there are few peripheral components, so…