Jameco 555 Taymer o'quv qo'llanmasi

1-pinni (tuproq) kontaktlarning zanglashiga olib ulang.
Apply a low-voltage pulse to Pin 2 (Trigger) to make the output (Pin 3) go high.
Use resistor R1 and capacitor C1 to determine the output duration.

Calculate R1 value using R1 = T * 1.1 * C1, where T is the desired timing interval.
Vaqtni aniq belgilash uchun elektrolitik kondansatkichlardan foydalanishdan saqlaning.
Use resistor values between 1K ohms and 1M ohms for standard 555 timers.

1-pinni (tuproq) kontaktlarning zanglashiga olib ulang.
Capacitor C1 charges through resistors R1 and R2 in astable mode.
Kondensator zaryad olayotgan paytda chiqish yuqori.
VoltagC1 bo'ylab e ta'minot hajmining 2/3 qismiga etaditage.

Chiqish hajmi yana yuqori bo'laditage bo'ylab C1 ta'minot hajmining 1/3 qismidan pastga tushaditage.
Grounding Pin 4 (Reset) stops the oscillator and sets the output to low.

555 taymer ICni qanday sozlash kerak

555 Taymer qo'llanmasi
By Philip Kane
The 555 timer was introduced over 40 years ago. Due to its relative simplicity, ease of use and low cost it has been used in literally thousands of applications and is still widely available. Here we describe how to configure a standard 555 IC to perform two of its most common functions – as a timer in monostable mode and as a square wave oscillator in astable mode.

555 Timer Tutorial Bundle Includes

555 Signals and Pinout (8-pin DIP)

Figure 1 shows the input and output signals of the 555 timer as they are arranged around a standard 8 pin dual-in-line package (DIP).

Pin 1 - Tuproq (GND) Bu pin kontaktlarning zanglashiga olib ulangan.
2-pin - Trigger (TRI) Past ovoztage (ta'minot hajmining 1/3 qismidan kamtage) Trigger kiritishiga bir lahzada qo'llanilsa, chiqish (3-pin) yuqori bo'lishiga olib keladi. Chiqish yuqori hajmgacha yuqori bo'lib qoladitage Eshik kirishiga qo'llaniladi (6-pin).

Pin 3 – Output (OUT) In the output low state the voltage will be close to 0V. In the output high state the voltage ta'minot hajmidan 1.7V past bo'laditage. Misol uchunample, agar ta'minot voltage - 5V chiqish yuqori voltage 3.3 volt bo'ladi. Chiqish 200 mA ga qadar manba yoki cho'kishi mumkin (maksimal quvvat manbai hajmiga bog'liqtagva).

Pin 4 – Reset (RES) A low voltagQayta tiklash piniga qo'llaniladigan e (0.7V dan kam) chiqish (pin 3) past bo'lishiga olib keladi. Ushbu kirish foydalanilmaganda Vcc ga ulangan bo'lishi kerak.

Pin 5 – Control voltage (CON) Siz pol balandligini boshqarishingiz mumkintage (6-pin) boshqaruv kirishi orqali (ichki ta'minot hajmining 2/3 qismiga o'rnatiladitage). Siz uni etkazib berish hajmining 45% dan 90% gacha o'zgartirishingiz mumkintage. Bu monostabil rejimda chiqish pulsining uzunligini yoki barqaror rejimda chiqish chastotasini o'zgartirishga imkon beradi. Foydalanilmayotganda, bu kirishni 0.01 uF kondansatör orqali kontaktlarning zanglashiga olib ulanishi tavsiya etiladi.
Pin 6 – Threshold (TRE) In both astable and monostable mode the voltage vaqt kondensatori bo'ylab Eshik kirishi orqali nazorat qilinadi. Qachon jildtage bu kirish chegara qiymatidan yuqoriga ko'tarilganda, chiqish yuqoridan pastgacha o'tadi.

Pin 7 – Discharge (DIS) when the voltage vaqt kondensatori bo'ylab chegara qiymatidan oshadi. Vaqt kondensatori ushbu kirish orqali zaryadsizlanadi
Pin 8 – Supply voltage (VCC) Bu ijobiy ta'minot hajmitage terminali. Ta'minot jildtage diapazoni odatda +5V dan +15V gacha. RC vaqt oralig'i ta'minot hajmi bo'yicha unchalik farq qilmayditage diapazoni (taxminan 0.1%) barqaror yoki monostabil rejimda.

Monostabil sxema

2-rasmda asosiy 555 taymer monostabil sxemasi ko'rsatilgan.

Referring to the timing diagram in figure 3, a low voltagTrigger kirishiga qo'llaniladigan impuls (2-pin) chiqish hajmini keltirib chiqaraditage pastdan yuqoriga o'tish uchun 3-pinda. R1 va C1 qiymatlari chiqish qancha vaqt davomida yuqori bo'lishini aniqlaydi.

During the timing interval, the state of the trigger input has no effect on the output. However, as indicated in Figure 3, if the trigger input is still low at the end of the timing interval, the output will remain high. Make sure that the trigger pulse is shorter than the desired timing interval. The circuit in figure 4 shows one way to accomplish this electronically. It produces a short-duration low-going pulse when S1 is closed. R1 and C1 are chosen to produce a trigger pulse that is much shorter than the timing interval.

As shown in figure 5, setting pin 4 (Reset) to low before the end of the timing interval will stop the timer.

Reset must return to high before another timing interval can be triggered.

Calculating the timing interval

Use the following formula to calculate the timing interval for a monostable circuit: T = 1.1 * R1 * C1
Where R1 is the resistance in ohms, C1 is the capacitance in farads, and T is the time interval. For example, if you use a 1M ohm resistor with a 1 micro Farad (.000001 F) capacitor the timing interval will be 1 second: T = 1.1 * 1000000 * 0.000001 = 1.1

Choosing RC components for Monostable operation

First, choose a value for C1.
The available range of capacitor values is small compared to resistor values. It’s easier to find a matching resistor value for a given capacitor.)
Next, calculate the value for R1 that, in combination with C1, will produce the desired timing interval.

Avoid using electrolytic capacitors. Their actual capacitance value can vary significantly from their rated value.
Also, they leak charge which can result in inaccurate timing values.

Instead, use a lower value capacitor and a higher value resistor. For standard 555 timers, use timing resistor values between 1K ohms and 1M ohms.

Monostable Circuit Example

Figure 6 shows a complete 555 monostable multivibrator circuit with simple edge triggering. Closing switch S1 starts the 5-second timing interval and turns on LED1. At the end of the timing interval LED1 will turn off. During normal operation switch S2 connects pin 4 to the supply voltage. To stop the timer before the end of the timing interval, you set S2 to the “Reset” position which connects pin 4 to ground. Before starting another timing interval you must return S2 to the “Timer” position.

Astable Circuit

Figure 7 shows the basic 555 astable circuit.

In astable mode, capacitor C1 charges through resistors R1 and R2. While the capacitor is charging, the output is high.
Qachon jildtagC1 bo'ylab e ta'minot hajmining 2/3 qismiga etaditage C1 discharges through resistor R2 and the output goes low.
Qachon jildtage bo'ylab C1 ta'minot hajmining 1/3 qismidan pastga tushaditage C1 zaryadlashni davom ettiradi, chiqish yana yuqoriga ko'tariladi va tsikl takrorlanadi.
8-rasmdagi vaqt diagrammasi barqaror rejimda 555 taymer chiqishini ko'rsatadi.

8-rasmda ko'rsatilganidek, Reset pinini (4) erga ulash osilatorni to'xtatadi va chiqishni past darajaga o'rnatadi. Qayta tiklash pinini yuqoriga qaytarish osilatorni qayta ishga tushiradi.
Davrni, chastotani va ish aylanishini hisoblash 9-rasmda 1 barqaror kontur tomonidan yaratilgan kvadrat to'lqinning 555 ta to'liq tsikli ko'rsatilgan.

The period (time to complete one cycle) of the square wave is the sum of the output high (Th) and low (Tl) times. That is: T = Th + Tl
Bu erda T - davr, soniyalarda.
You can calculate the output high and low times (in seconds) using the following formulas: Th = 0.7 * (R1 + R2) * C1 Tl = 0.7 * R2 * C1
or, using the formula below, you can calculate the period directly. T = 0.7 * (R1 + 2*R2) * C1
Chastotani topish uchun davrning o'zaro nisbatini oling yoki quyidagi formuladan foydalaning:

Bu erda f sekundda yoki gertsda (Hz).
Misol uchunample, 7-rasmdagi barqaror sxemada, agar R1 68K ohm, R2 680K Ohm va C1 1 mikro Farad bo'lsa, chastota taxminan 1 Gts:

Vazifa aylanishi - bu foiztagbir to'liq tsikl davomida chiqish yuqori bo'lgan vaqt. Misol uchunample, agar chiqish Th soniya uchun yuqori va Tl soniya uchun past bo'lsa, ish aylanishi (D) bo'ladi:

Biroq, ish aylanishini hisoblash uchun siz R1 va R2 qiymatlarini bilishingiz kerak.

C1 R1 va R2 orqali zaryadlanadi, lekin faqat R2 orqali zaryadsizlanadi, shuning uchun ish aylanishi 50 foizdan oshadi. Biroq, R50 R1 dan ancha kichik bo'lishi uchun kerakli chastota uchun rezistorlar birikmasini tanlab, 2% ga yaqin ish aylanishini olishingiz mumkin.
Misol uchunampAgar R1 68,0000 2 ohm va R680,000 52 XNUMX ohm bo'lsa, ish aylanishi taxminan XNUMX foizni tashkil qiladi:

R1 R2 bilan qanchalik kichikroq bo'lsa, ish aylanishi 50% ga yaqinroq bo'ladi.

50% dan kam bo'lgan ish aylanishini olish uchun diodni R2 bilan parallel ravishda ulang.

Choosing RC components for Astable operation

Choose C1 first.
Calculate the total value of the resistor combination (R1 + 2*R2) that will produce the desired frequency.
Select a value for R1 or R2 and calculate the other value. For example, aytaylik (R1 + 2 * R2) = 50K va siz R10 uchun 1K rezistorni tanlaysiz. Keyin R2 20K ohm qarshilik bo'lishi kerak.

50% ga yaqin ish aylanishi uchun R2 uchun R1 dan sezilarli darajada yuqori bo'lgan qiymatni tanlang. Agar R2 R1 ga nisbatan katta bo'lsa, siz hisob-kitoblarda dastlab R1 ni e'tiborsiz qoldirishingiz mumkin. Misol uchunample, faraz qilaylik, R2 qiymati 10 marta R1 bo'ladi. R2 qiymatini hisoblash uchun yuqoridagi formulaning ushbu o'zgartirilgan versiyasidan foydalaning:

Keyin R10 qiymatini topish uchun natijani 1 yoki undan ko'pga bo'ling.
Standart 555 taymerlar uchun 1K ohm va 1M ohm oralig'idagi vaqt qarshiligi qiymatlaridan foydalaning.

Barqaror sxema Example

10-rasmda taxminan 555 Gts chastotali va taxminan 2 foiz ish aylanishiga ega 50 kvadrat to'lqinli osilator ko'rsatilgan. SPDT kaliti S1 "Start" holatida bo'lsa, chiqish LED 1 va LED 2 o'rtasida almashadi. S1 "To'xtash" holatida bo'lganda, LED 1 yoniq bo'lib qoladi va LED 2 o'chadi.

Kam quvvatli versiyalar

The standard 555 has a few characteristics that are undesirable for battery-powered circuits.
It requires a minimum operating voltage of 5V and a relatively high quiescent supply current.

During output transitions, it produces current spikes of up to 100 mA. Additionally, its input bias and threshold current requirements impose a limit on the maximum timing resistor value, which limits the maximum time interval and astable frequency.
Low-power CMOS versions of the 555 timer, such as the 7555, TLC555 and the programmable CSS555, were developed to provide improved performance, especially in battery-powered applications.
They are pin compatible with the standard device, have a wider supply voltage diapazoni (masalanample, 2V to 16V for the TLC555) and require significantly lower operating current.

They are also capable of producing higher output frequencies in astable mode (1-2 MHz, depending on the device) and significantly longer timing intervals in monostable mode.
These devices have low output current capability compared to the standard 555. For loads greater than 10 – 50 mA (depending on the device) you will need to add a current boost circuit between the 555 output and the load.

Qo'shimcha ma'lumot uchun

Consider this a short introduction to the 555 timer.
For further information, be sure to study the manufacturer’s data sheet for the specific part that you are using.

Also, as a quick Google search will verify, there is no shortagUshbu ICga bag'ishlangan ma'lumotlar va loyihalar e web.
Misol uchunample, quyidagi website provides more detail on both standard and CMOS versions of the 555 timer www.sentex.ca/~mec1995/gadgets/555/555.html.

TSS

Savol: 555 taymerdagi Trigger va Threshold kirishlarining maqsadi nima?

A: The Trigger input causes the output to go high when a low voltage is applied while the Threshold input stops the output from being high when a high voltage qo'llaniladi.

Savol: Standart 555 taymerda vaqtni hisoblash uchun tavsiya etilgan qarshilik qiymatlari diapazoni qanday?

A: It is recommended to use resistor values between 1K ohms and 1M ohms for accurate timing in a standard 555 timer configuration.

Hujjatlar / manbalar

Jameco 555 taymer qo'llanmasi [pdf] Foydalanuvchi uchun qoʻllanma
555 Taymer qo'llanmasi, 555, Taymer qo'llanmasi, o'quv qo'llanma

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