1, NE555 (TimerIC) is an 8-pin time-base integrated circuit, released by the SigneticsCorporation circa 1971, at the time was the only very fast and commercial TimerIC. The NE555 is small in size, light in weight, stable and reliable, with a large operating power supply range, strong current supply capacity at the output end, high timing accuracy, good temperature stability, and cheap price.
2, ne555 pin diagram and functions VCC: positive terminal, access to power supply; GND: negative terminal, access ground cable. CONT: Control terminal, passThe external capacitor can adjust the frequency and duty cycle. RESET: Reset terminal. When the terminal is grounded, the chip stops working and is reset. OUT: output terminal, output square wave signal; THRESH: non-reverse input of voltage comparator; TRIG: reverse input of voltage comparator; DISC: The power end of the amplifier is connected to the low-pass filter element.
3, timer is a combination of analog and digital functions of the medium scale integrated device. Generally, the one made by the bipolar process is called 555, and the one made by the CMOS process is called 7555, in addition to the single timer, there are corresponding double timersAgreed. The SE555 contains a comparator, an RS flip-flop, and a discharge transistor. When the external pin receives the appropriate signal, these internal components work together to produce the desired output waveform.
3, the principle of SE555 chip is based on integrated circuit technology to achieve specific functions of the electronic chip. The design principle of the chip covers many aspects such as circuit design, manufacturing process and package testing. First, the circuit design of the SE555 chip is at the heart of its working principle. Circuit design mainly includes logic design, layout design and layout design. Logical design is based onThe functional requirements of the chip, determine the logical relationship and control process of each circuit module inside the chip.
4, the voltage control end K (pin 5) is not connected to the external control voltage and is connected to the high-frequency interference bypass capacitor C2 (0.01uF). The direct reset terminal R (pin 4) is connected to a high level, so that the NE555 is in the non-reset state.
5, the SE555 chip is a single crystal oscillator, with timing and frequency control capabilities in the circuit. It can realize various functions, such as pulse modulation, square wave generation, time series generation, quantity generation and timing measurement. At the same time, it is also possible to adjust the externalElectronic components to change their output frequency and duty cycle. The chip has two operating modes: monostable and multistable, which can be switched as needed.
6, the SE555 chip has three main operating modes: monostable flip-flop, multivibrator and Schmidt flip-flop. These operating modes are determined by the configuration of external resistors and capacitors. In monostable mode, the SE555 generates a fixed width or single pulse, which is often used to trigger other circuits or devices. In multivibrator mode, the SE555 can generate continuous square waves, which is suitable for applications where periodic signals are required.
Open the Multisim software. Select the Components option in the toolbar. In the open component library, select the Timer category. In the timer category, you can find the 555 chip. Click on it and add it to your circuit diagram. Opening Multisim You need to install and open Multisim first. This is a software specifically designed for circuit design and simulation.
mNE555 in ultisim14 is easy to find, click "Tools" and select "555 Timer Wizard" from the drop-down menu, as shown in the figure: Then a wizard dialog box will appear, select the monostable or non-stable circuit in this dialog box, and set the relevant component parameters, and click "Build circuit", the mouse arrow will load the selected circuit, and the single left button on the drawing will place the selected circuit.
1, the steps are as follows: Cut off the power: ensure that the socket is safeTo perform operations, first cut off the power supply. Unplug the chip: Remove the chip from the socket if it is safe to do so. Reverse the chip: Insert the wrong side of the chip into the socket in the correct direction. Connect the power supply: Connect the power supply to ensure that the socket is working properly. 2, Connect the circuit: Plug the 555 timer chip into the socket or solder it to the circuit board, and then connect the other components as follows: Connect the power supply positive (VCC) to the positive pin of the 555 chip (usually pin 8). Connect the negative power supply (GND) to the negative pin of the 555 chip (usually pin 1). Connect a currentOne end of the container goes to the negative pin of the 555 chip (usually pin 1).
3, to establish a 1-minute timer (60 seconds) need 55k ohm resistance and 1000uf capacitor: 1*55k*1000uF (1*55*1000*1000) /1000000 = 60.5 ~ 60 seconds. When pin 3 outputs a low level, the LED lights up, outputs a high level, and the LED turns off.
4, you can try to execute CMOS reset, part of the phenomenon that can not be turned on can be solved by this way. Remove power adapterPress and hold the power button for 40 seconds (hold and hold) to connect the power adapter, and then power on to confirm that the problem is removed if the problem persists, please continue to refer to the following detailed steps.
5, 3, circuit analysis When the power is turned on, if the control switch is closed or the moving contact is in contact with the static contact, the alarm is in standby state; When the control switch is open, the door opens and the alarm alarms; (Conversely) the ideal working voltage of the alarm is 9V, when the working voltage is 9V, the standby current is about 3mA, and the working current is about 8mA.
6, touch the timing switch integrated circuitIC1 is a 555 timing circuit, which is connected to a monostable circuit. Usually, because there is no induction voltage at the P end of the touch piece, the capacitor C1 is discharged through the 7th pin of 555, the output of the 3rd pin is low, the relay KS is released, and the lamp is not bright.
1, SE555 chip details SE555 is a commonly used integrated circuit, is widely used in a variety of timing, oscillation, pulse generation and modulation circuits. It belongs to the 555 timer family and is a highAnalog and digital hybrid integrated circuits that are stable and easy to use. The SE555 chip has three main operating modes: monostable flip-flop, multivibrator and Schmitt flip-flop.
2, the SE555 chip is a single crystal oscillator, with timing and frequency control capabilities in the circuit. It can realize various functions, such as pulse modulation, square wave generation, time series generation, quantity generation and timing measurement. At the same time, the output frequency and duty cycle can be changed by adjusting the external electronic components. The chip has two operating modes: monostable and multistable, canSwitch as needed.
3, SE555 chip is a powerful integrated circuit, widely used in a variety of electronic devices. It has the characteristics of high performance, low power consumption and high reliability, and is recognized by the majority of users. The performance of the SE555 chip is excellent. It adopts advanced process technology and circuit design, which can realize high-speed operation and low power consumption.
4, SE555 chip is an integrated circuit, belongs to a timer chip, used for timing and waveform generation and other applications. It uses a bistable multivibrator, which can produce various kinds of pulse waveformsAnd signal. The principle is as follows: Basic circuit: The SE555 chip contains a comparator, three steady-state circuits, current sources, output stages and other circuits, through which a variety of timer circuits can be formed.
Connect the output pin (usually pin 3) of the 555 chip to the desired circuit or load. Calculate component values: Calculate the delay time according to the capacitor and resistor values you have selected.
The following isSteps for designing a one-second delay circuit with a 555 timer: Connect the circuit: Insert the 555 timer chip into the circuit board and connect its power pins (Pin1 and Pin8). Connect a 10uF electrolytic capacitor between Pin6 and Pin2 and connect a 10k resistor to Pin7. Next, connect a 10k resistor to Pin6 and a 0.1uF ceramic capacitor to Pin5.
Foot drop trigger signal, 3 pin output, output high level after triggering, 1 second to return to low level.
Function of a monostable circuitIs when the circuit triggered the signal, the circuit output switching signal. When the output time of the switching signal reaches the time constant of the RC circuit, the circuit automatically resets. If you only have a delay effect, you can use 555 to make a delay circuit, similar to the monostable circuit, it is also very simple, and the peripheral parts are very few.
As shown in the figure, the adjustment time is realized by the potentiometer, the shortest time is determined by the 100k resistance, the parameter in the figure is less than 10 seconds, to be very accurate, please experiment to modify its value. 100uF timing capacitor leakage current should be smaller, it is best to use tantalum electrolysis.