- #1
Beckman44
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How would i do this?
Can the 555 timer be set to its maximum frequency of 500kHz?
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Discussion Overview
The discussion revolves around the use of the 555 timer, specifically addressing how to configure it to achieve its maximum frequency of 500kHz. Participants explore the theoretical and practical aspects of programming the timer, including circuit design and component selection.
Discussion Character
- Technical explanation
- Conceptual clarification
- Debate/contested
- Mathematical reasoning
Main Points Raised
- Some participants inquire about the method to program a 555 timer to produce rapid pulses, such as for gaming applications.
- There is a suggestion to read the 555 timer's datasheet to understand how to configure the circuit for desired pulse rates.
- One participant questions the applicability of the LM555 datasheet to CMOS 555 timers, seeking clarification on whether they operate the same way.
- Another participant provides equations related to the frequency, period, and duty cycle of the 555 timer's output, indicating how resistor and capacitor values influence these properties.
- Concerns are raised about the performance of many 555 timers at frequencies around 500kHz, suggesting potential limitations.
Areas of Agreement / Disagreement
Participants express varying levels of understanding regarding the configuration of the 555 timer and the relevance of the datasheet. There is no consensus on the best approach to achieve the desired frequency, and some participants challenge each other's understanding and assumptions.
Contextual Notes
Participants mention the importance of selecting appropriate resistor and capacitor values to achieve specific frequencies and duty cycles, but there are unresolved questions about the practical implementation and limitations of the 555 timer at high frequencies.
Who May Find This Useful
This discussion may be useful for electronics enthusiasts, students learning about timer circuits, and individuals interested in practical applications of the 555 timer in projects.
- #2
chroot
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What does this even mean?
- Warren
- Warren
- #3
Beckman44
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sorry if this was not understandable...here i go again...
how would i program a 555 timer so when i activate it it tells something else that it is doing a certain action many times.
Ex. Holding down a button and Xbox Controller shooting as fast as possible
how would i program a 555 timer so when i activate it it tells something else that it is doing a certain action many times.
Ex. Holding down a button and Xbox Controller shooting as fast as possible
- #4
Beckman44
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a better question would be how do you adjust the rate of a 555 timers pulses?
- #5
chroot
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You should consider reading the 555's datasheet.
- Warren
- Warren
- #6
Beckman44
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where could i find this?
- #7
chroot
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- #8
Beckman44
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what will the data sheet do for me?
- #9
chroot
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It'll teach you how to configure the circuit to produce any kind of pulses you want. Look in the Applications section.
- Warren
- Warren
- #10
Beckman44
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http://www.westfloridacomponents.co...&Category_Code=SurfaceMountICs&Store_Code=wfccould u tell me? i can't find the DATA SHEET
- #11
chroot
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You've got to be kidding me. I gave you a link to a Google search of the words "555 datasheet." The very first link points you to a datasheet:
http://www.national.com/ds.cgi/LM/LM555.pdf
- Warren
http://www.national.com/ds.cgi/LM/LM555.pdf
- Warren
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- #12
Beckman44
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i can't just use a pot?
- #13
chroot
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Beckman44, you really need to spend at least a bit of time doing your own reading. The datasheet will tell you everything you need to know to calculate R and C values to get whatever frequency and duty cycle you'd like. The datasheet is the ultimate document from which to learn how to use an electronic device. If you can't understand the datasheet, or if you try to use what you've learned and still can't get it to work as you'd like, then come ask questions. Spend an hour, read the datasheet's Applications section a few times over, and then come back if you still need help.
- Warren
- Warren
- #14
Beckman44
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i don't know if I am misunderstanding or u...but is lm555(used int he guide) the same as cmos 555 timer? i mean do they change the same?...and i see nothing in there telling how to actually change the chip itself...it says how to get a rate but now how YOU change the chip...What materials you neeed.
- #15
chroot
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Beckman44,
Every "555" timer, from every manufacturer, is going to operate the same way. They're known as "second source" parts, and are functionally identical.
I don't know what you mean by "changing the chip." To configure a 555 timer, you connect some capacitors and resistors to it. The values of these components determines the frequency of the oscillation, etc.
You need to ask more detailed questions if you want more detailed answers.
- Warren
Every "555" timer, from every manufacturer, is going to operate the same way. They're known as "second source" parts, and are functionally identical.
I don't know what you mean by "changing the chip." To configure a 555 timer, you connect some capacitors and resistors to it. The values of these components determines the frequency of the oscillation, etc.
You need to ask more detailed questions if you want more detailed answers.
- Warren
- #16
the one
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Hi Everyone ,
Beckman44 , I Understand That you need to produce pulses as fast as possible , So you need to use an astable circuit like the one in the attachments .
There are Some Equations Control The Properties of the pulses and they are :
( The frequency Equation )
\[<br /> f = \frac{{1.44}}{{C(R_1 + 2R_2 )}}<br /> \]
( The Period Equation )
\[<br /> \tau = \frac{1}{f} = \frac{{C(R_1 + 2R_2 )}}{{1.44}}<br /> \]
( The Duty Cycle Equation )
\[<br /> Duty{\rm }Cycle = \frac{{R_1 + R_2 }}{{R_1 + 2R_2 }}<br /> \]
You See That the Resistors and the Capacitor Control The Time Properties of the pulses , So by the good Choise of them you can get any pulses you want .
Beckman44 , I Understand That you need to produce pulses as fast as possible , So you need to use an astable circuit like the one in the attachments .
There are Some Equations Control The Properties of the pulses and they are :
( The frequency Equation )
\[<br /> f = \frac{{1.44}}{{C(R_1 + 2R_2 )}}<br /> \]
( The Period Equation )
\[<br /> \tau = \frac{1}{f} = \frac{{C(R_1 + 2R_2 )}}{{1.44}}<br /> \]
( The Duty Cycle Equation )
\[<br /> Duty{\rm }Cycle = \frac{{R_1 + R_2 }}{{R_1 + 2R_2 }}<br /> \]
You See That the Resistors and the Capacitor Control The Time Properties of the pulses , So by the good Choise of them you can get any pulses you want .
Attachments
- #17
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I agree with chroot that it's good to become familiar with looking at datasheets. In the National datasheet, what you want starts on p. 7 under "ASTABLE OPERATION":
http://www.national.com/ds/LM/LM555.pdf
Figs. 4 and 6 are particularly relevant, as is the equation for "f=..." on p. 8.
http://www.national.com/ds/LM/LM555.pdf
Figs. 4 and 6 are particularly relevant, as is the equation for "f=..." on p. 8.
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- #18
fedaykin
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Just an FYI, many 555s don't work so well starting at around 500kHz.