changeable timer circuits with 555 timer ic

Thread Starter

dashhossein

Joined Jul 30, 2020
42
hello every one .
for a project i want to use IR receiver
the application is when IR sensor switched high the operator connect a relay for 40 second then switch that to close and waiting for another 1 or high voltage from receiver.
the important part is when for example 20 second elapsed from an start and the IR sensor received another high the operator restart the cycle and continue the relay connect's for another 40 second
is that possible ?
anyone could help me to solve this please ?
 
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Thread Starter

dashhossein

Joined Jul 30, 2020
42
yes its possible with a 4060 counter,
BUT
I'd not try it,

clock at say 32.768 KHz, how big a counter do you need ?

if its not for homework, and its for a practical application, a processor is your friend,
Arduino is easy to learn, low power, flexible, and cheap
one of many https://www.pjrc.com/store/teensy40.html
actually i understood that 555 counter ic it's much better for my project
then i want to do this project without programming
overestimately i need a 100 seconds timer
 

jpanhalt

Joined Jan 18, 2008
11,088
If I understand what you want, look up "re-triggerable" 555 circuits. Basically, you are describing a "one shot" that puts out a pulse for 40 seconds.

There are two types of such designs, non-retriggerable and retriggerable. A non-retriggerable version would put out a pulse of 40 seconds regardless of how many times it was signaled during that pulse. A retriggerable version puts out a pulse beginning with the first trigger and continues the pulse for 40 seconds after the last trigger was received.
 

dl324

Joined Mar 30, 2015
12,790
overestimately i need a 100 seconds timer
Where do you get 100 seconds? It sounds like you're describing a retriggerable 40 second one shot.

40 seconds is long for a 555 timer; you'll need something like 100uF with 365k. What kind of accuracy do you need? You could use a smaller cap and larger resistor with the CMOS version.
 

andrewmm

Joined Feb 25, 2011
1,240
actually i understood that 555 counter ic it's much better for my project
then i want to do this project without programming
overestimately i need a 100 seconds timer

did this thread not originally say 4046 counter needed in the project , or is my eye site worse than I imagined..
 

Thread Starter

dashhossein

Joined Jul 30, 2020
42
If I understand what you want, look up "re-triggerable" 555 circuits. Basically, you are describing a "one shot" that puts out a pulse for 40 seconds.

There are two types of such designs, non-retriggerable and retriggerable. A non-retriggerable version would put out a pulse of 40 seconds regardless of how many times it was signaled during that pulse. A retriggerable version puts out a pulse beginning with the first trigger and continues the pulse for 40 seconds after the last trigger was received.
i certainly want something like this in this video below instead of buzzer, operate a relay for 40 seconds
is that possible?

 

Thread Starter

dashhossein

Joined Jul 30, 2020
42
I'm not going to waste 7 minutes watching a YouTube video by some so called expert. What did the video show?
the video show pir sensor after operate a led blinking
i want a stable connect not blinking
is that possible ,
i dont want how
i want only yes or no answer ?
 

jpanhalt

Joined Jan 18, 2008
11,088
the video show pir sensor after operate a led blinking
i want a stable connect not blinking
is that possible ,
i dont want how
i want only yes or no answer ?
You are apparenttly clueless about analog electronics. Describe as best you can what the homework assignment wants you to do.
 

Thread Starter

dashhossein

Joined Jul 30, 2020
42
Show us your schematic. I have no idea what you mean.
for simplize my mean
i want turn on a led for 40 seconds with pir sensor detection
in that tutorial turn on led in blinking mode
i don't want blinking mode , just turn on for 40 seconds from last trigger
is that possible ? (yes or no)
 

Thread Starter

dashhossein

Joined Jul 30, 2020
42
You are apparenttly clueless about analog electronics. Describe as best you can what the homework assignment wants you to do.
actualy i not clueless about the analog
i think in this way will be more stable and cheaper"not want to use arduino or coding"
 
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