HC595, 74LS165, etc. According to the query, the driver chip of the 3-bit digital tube is commonly used 74HC595, 74LS165, 74Ls164, TM1617 and so on. When using 74HC595, each segment should add a series resistor, and pay attention to whether the refresh frequency is too low when programming, otherwise it will produce obvious blinking phenomenon.
TM1617 can, there are LED nixie driver IC selection table and a full set of specifications for everyone to download, reference selection table can be their own selection. I hope it helps.
If I guess correctly, this is the digital voltmeter head product of Yuanbo Electronics. According to its company personnel reply: this chip is a specially customized MCU of the company, which cannot be purchased on the market, but it can be ordered by mail from the company at the cost of express delivery.
MC14513BCP is BCD - seven-segment decoding/driver; TC4069UBP is a six-phase inverter; 74HC32N is a four-channel two-input or gate; CD4094 and HEF4094BP are 8-bit shift registers; HEF40106B is a six-Schmidt inverter; CD74HC123E is a dual-channel monostable multiharmonic flip-flop; C04011BCN is a four channel two input and not gate.
The current of the small LED inside the LED nixie tube generally cannot exceed 20mA, otherwise it is easy to burn. Adding resistance can control the current at about 15mA, and has an inhibitory effect on the surge current, which can protect the LED.
The nixie is a current driving element, and the driving voltage should exceed the maximum operating voltageThe series current limiting resistor ensures that the peak current through the digital tube is below the limit working current, preferably the rated current value.
With ordinary IC drivers, it is necessary to connect the current limiting resistor, because the voltage on the LED of the digital tube is less than 2V, and the output voltage of the IC is higher. Dedicated nibley drive IC, the current limiting measures have been solved inside the IC, the external current limiting resistance is no longer required.
The nixie requires a current-limiting resistor, because the voltage on the LED of the nixie is less than 2V, and the output voltage of the IC is higher. A digital tube, also known as a glow tube, is an electron that displays numbers and other informationThe jitter circuit. Keyboard interrupt, you can choose low level active output or low level pulse output. Provides key release flag bits for querying key press and release. The CH452 in low-power and power-saving mode can be awakened by some keys.
2, alas. Change the circuit board. Add a switch, 340 has been power supply, the switch is used to control the MCU power supply. However, it is said that there is also a power-free download method, that is, to change the upper computer, can not use the isp software stc. I always wanted to study it, but I didn't have enough timeThere are many power-free download methods on the Internet, you can search.
3, you have to figure out the meaning of power-on reset, take single-chip microcomputer as an example: reset circuit is composed of two parts, capacitance and resistance. When the system is powered on, the voltage on the VCC will be at a high level for a period of time at the RESET point, and then because the point is grounded through the resistance, the level of the RESET point will gradually change to a low level, so that the level of the reset port of the single-chip microcomputer will be from 1 to 0, so as to achieve the function of resetting the single-chip microcomputer.
4, this is actually a serial communication program. CH452 and CH451It makes no difference. The code for this chip is available online. Then you find a serial communication program. Find a microcontroller more powerful classmate let him help you change the program, on the line.
2, first of all, the analog-to-digital conversion chip is not only designed and produced for the led digital tube driver chip experiment, so the voltmeter application requirementsDifferent and what type of analog-to-digital conversion chips are available, but for the led niqtube driver chip volume considerations, there will be certain requirements for the package form of the chip.
3, JX1126 is a single integrated LED digital display voltmeter control chip, 3-digit digital tube display, voltage display range 0V-39V. The IC has an output pin that can be connected to a buzzer. When the voltage is less than 10V, the buzzer will ring long; when the voltage is 11V-15V, the buzzer will not ring; when the voltage is 16V-22V, the buzzer will ring long.In the 23V-30V range, the buzzer does not ring, and in the 31V-39V range, the buzzer will ring for a long time.
4, if you are not wrong to guess, this is the digital voltmeter head product of Yuanbo Electronics. According to the company's personnel reply led digital tube driver chip : This chip is a specially customized MCU of the company, which cannot be purchased on the market, but can be ordered by mail from the company at express costs.
1, first you have to know, each digital tube this 8A section of the LED is equivalent to a light-emitting diode LED, the operating current is about 5mA. To drive this LED, rely on single-chip IO direct output definitely not. LED drive general small power plastic package triode (9018550, 2N3906 these) operating current is greater than 5mA, so it can definitely work.
2, the principle of the nixie drive circuit is to use a signal called segment selection, select the digital segment to be displayed, and provide current for the digital segment, so that it lights up. Then, using a signal called bit selection, select the number displayed and the number of the selected numberCode segments provide electrical current, which causes them to light up. The nib drive circuit is usually composed of two parts: segment selection circuit and bit selection circuit.
3, connection: the pins of the 74HC595 chip are connected with the digital tube, including serial input, clock input, parallel output and output enable pins. Data transmission: The single chip computer will convert the displayed numbers into binary data, and input the serial input pin to the 74HC595 chip. Shift operation: Clock input pin clock signal, so that the input binary data inside the 74HC595 chip for shift operation.
4, refers to eachEach segment of the nixie is driven by the I/O port of a single chip microcomputer, or is driven by decoding such as BCD code 2-decimal decoder. The advantage is simple programming, high display brightness, and the disadvantage is that it occupies many I/O ports. It is to control the COM end of each digital tube by time-sharing in turn, so that each digital tube takes turns to control the display.
1, ls248 is a 4-wire seven-segment decoder driver BCD input, with pull-up resistance, 248 is a BCD seven-segment decoder/driver with internal pull-up resistance, with a total of 5474248 and 5474LS248 two line structure types.
2, LS192 is a double clock, can be preset number, asynchronous reset, decimal (BCD code) reversible counter, can also choose 54HC192, 54HCT192, 74HC192, 74HCT192 and so on.
3, HD74LS47P is Schmidt inverter integrated circuit, Schmidt gate circuit is characterized by voltage reversal when hysteresis phenomenon, more used in shaping circuit, antiThe ability of clutter and shaking interference is stronger than that of ordinary gate circuits. Each piece contains six channels of Schmidt inverter, each inverter input for high voltage output low level, input for low voltage output high level. It's used in some ultrasound therapy machines.
4, digital decoding driver using two 74LS248 integrated block, 74LS248 for four-wire - seven segment decoder/driver, internal output with a pull resistor, it is transmitted from the counter to the two-decimal 8421 code into decimal code, and drive the digital tube display digital. Digital-to-analog conversion circuit adopts two DAC0832 setsTo block, it is an 8-digit/analog converter, here only the high 4-digit quantity input end is used.
5, LS248 (74LS48) is a display decoder from BCD code to seven-segment code, which can directly drive a common cathode nixie. Its pin diagram is shown in Figure 5. The display uses LC5011-11 common cathode LED display. (Note: In multisim simulation, the decoding display DCD_HEX can be used instead of the decoding and display unit).
6, display is different, chip is different. Display different: 74LS48 and 74LS248The function is the same, but the 74LS248 is different from the 74LS48 when displaying the numbers 6 and 9. The 74LS248 chip has a built-in driver, while the 74LS48 chip does not have a built-in driver.