Producing a Time Delay of 44 Seconds with a 555 Timer

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Discussion Overview

The discussion revolves around producing a time delay of 44 seconds using a 555 timer in an electronics project. Participants explore various methods to achieve this delay, including both analog and digital approaches, while addressing the feasibility and practicality of their suggestions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant suggests using a 555 timer in monostable mode to create a single pulse delay, indicating that this method could be effective for the project.
  • Another participant proposes an alternative method involving voltage-controlled switches and capacitor discharging, but favors the 555 timer approach as the best option.
  • A later post clarifies the original question, asking how to split a 44-second delay into two or three parts, indicating a desire for fewer timing components.
  • One participant interprets the clarification as a request for a sequence of delays, suggesting a 22-second on-off cycle.
  • Another participant recommends using a more stable oscillator and a long down-counter chain, mentioning specific components like a 32kHz watch crystal and an HC4060 counter to achieve the desired delay.
  • A different participant suggests that a microcontroller (uP) might be a better solution for generating multiple variable time delays.
  • The original poster shares feedback from their advisor, who expressed skepticism about the practical application of the 555 timer for their specific frequency requirements, suggesting that it may not work as intended in practice.

Areas of Agreement / Disagreement

Participants present multiple competing views on how to achieve the desired time delay, with no consensus reached on the best method. The discussion includes both analog and digital approaches, reflecting differing opinions on practicality and effectiveness.

Contextual Notes

Some limitations are noted regarding the practical application of the 555 timer at high frequencies, as mentioned by the original poster's advisor. The discussion also highlights the need for clarity in the requirements for the timing intervals.

Who May Find This Useful

Electronics enthusiasts, students working on timing circuits, and individuals interested in practical applications of timers and oscillators in projects may find this discussion relevant.

Mc.
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Hi, everyone.
I am currently involved in a small electronics project and I am required to produce a time delay for part of the project. I plan on using the famous 555 timer and not quite sure on what to do to produce this delay.So please anyone help explain how to produce a time delay of,say for example 44 seconds.
 
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There are many ways to create a delay. Two I'm thinking of now are here:

1.) Use a 555 timer in monostable mode. This way, you'd push a button that activates the 555's trigger, and it would put out a pulse of a delay you'd specify. If whatever you're delaying for needs Vcc to be on, you could connect the 555 through an inverter or something to the device.

http://cache.national.com/ds/LM/LM555.pdf

2. You could do some things with voltage controlled switches and capacitor discharging, but honestly, I think option 1 is your best bet.
 
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Yeh, thanks that works very well but I think my question was not clear enough and I apologise for that.The question should have been something like this;Say you have made a one shot time that actually has a time width of 44 seconds, how possible it is to split this interval to,say, two or three parts. The main idea I have is to use few times as possible.
 
Did you mean it will run for 22s - stop - then run 22s?
 
I'd suggest that instead of using a 555, you could use a more stable oscillator and a long down-counter chain. You could use a 32kHz watch crystal, for example, and an HC4060 14 bit ripple counter to get close to a 1 second square wave, and then use another HC4060 to count out to multiple seconds. With a little logic, you can generate any delay you want out in the 44 second range.
 
If you need multiple time delays of variable length then a uP come to mind.
 
Hey thanks guy for you answers they gave me more knowladge on digital stuff.
I met my advisor and I asked him about the ideas I have on time delays and he said that a 555 time in one shot will work on a workbench but not practically. He also said that the frequency I will be using will be too high for physical components.
I will probably stick to timers.

Thank you guy for your contributions.
 

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