Understanding 555 Timer Monostable Mode

  • Thread starter Thread starter Ali Inam
  • Start date Start date
AI Thread Summary
In monostable mode, the 555 timer functions as a "one-shot" pulse generator, remaining in a LOW output state until triggered. Upon triggering, it briefly switches to a HIGH output before returning to the LOW state after a set duration. This mode produces a single output pulse for each trigger event. In contrast, astable mode generates continuous HIGH and LOW pulses, creating a regular frequency of output. The discussion also touches on how the timer resets after the pulse duration, similar to a self-resetting timer in PLC logic.
Ali Inam
Messages
99
Reaction score
0
Can anyone please tell me what does this sentence means ?


In the monostable mode, the 555 timer acts as a “one-shot” pulse generator.
 
Engineering news on Phys.org
"Monostable" means that the device has one stable state that it can remain in indefinitely.

When set in monostable mode, a 555 timer will remain with a LOW output (the stable state) until the cows come home. When it is triggered, it is kicked into an unstable state, with a HIGH output.

After a specific amount of time, the 555 returns to the LOW, stable state.

One trigger produces one output pulse. That's why it's called "one-shot".
 
If I connect a potentiometer with the Trigger, would I be able to get HIGH & LOW immediately one after another ?
 
In astable mode, the 555 timer puts out a continuous stream of rectangular pulses having a specified frequency.


So this means that in the Astable mode, the 555 timer is having continuous pulses, which means that continuous HIGH & LOW are being generated in this mode ?


Right ? !
 
one-shot is a self resetting timer.. in ladder logic the same bit location being true is what resets the timer.. know what I mean?

And the duration of pulses produced by the timer is equal to the timer value

The one-shot only keeps the output address that starts the timer true for one PLC scan...then returns low once reset.

Hope I helped...
 
While I was rolling out a shielded cable, a though came to my mind - what happens to the current flow in the cable if there came a short between the wire and the shield in both ends of the cable? For simplicity, lets assume a 1-wire copper wire wrapped in an aluminum shield. The wire and the shield has the same cross section area. There are insulating material between them, and in both ends there is a short between them. My first thought, the total resistance of the cable would be reduced...
Hi all I have some confusion about piezoelectrical sensors combination. If i have three acoustic piezoelectrical sensors (with same receive sensitivity in dB ref V/1uPa) placed at specific distance, these sensors receive acoustic signal from a sound source placed at far field distance (Plane Wave) and from broadside. I receive output of these sensors through individual preamplifiers, add them through hardware like summer circuit adder or in software after digitization and in this way got an...
I am not an electrical engineering student, but a lowly apprentice electrician. I learn both on the job and also take classes for my apprenticeship. I recently wired my first transformer and I understand that the neutral and ground are bonded together in the transformer or in the service. What I don't understand is, if the neutral is a current carrying conductor, which is then bonded to the ground conductor, why does current only flow back to its source and not on the ground path...
Back
Top