Momentary pulse from constant 12v dc supply

Thread Starter

Taptotweet

Joined Mar 5, 2013
4
Hey all,
I currently have a project that requires a pulse to trigger an MP3 player. My problem is, the "trigger" signal is a constant 12 volt supply. In a nutshell, I need some way to create a short dc pulse from a constant 12 volt dc input.

Any help is much appreciated.

Cheers, Sam.
 

thatoneguy

Joined Feb 19, 2009
6,359
What voltage does the pulse need to be?
What duration is required for the pulse?
Does the pulse need to be repeated? If so, how often?
What is your skill level with electronic circuit assembly?

Finally, what is the airspeed of an unladen European Swallow?
 

MMH

Joined Feb 8, 2013
143
You can use a 555 timer if you want. But What voltage does the pulse need to be, What duration is required for the pulse, Does the pulse need to be repeated? If so, how often? thatoneguy is right.
 

Thread Starter

Taptotweet

Joined Mar 5, 2013
4
Thanks for the replies!

I guess I should have been more specific. I need either a 12vdc or 5vdc pulse for a second or so. The pulse doesn't need to be repeated.

Cheers, Sam
 

thatoneguy

Joined Feb 19, 2009
6,359
So, the pulse starts when 12V is applied?

I guess if you explain the purpose, so many details wouldn't be needed.

There's another thread where I made a schematic for a timed pulse out at power on, it would just be a matter of changing two components to change duration of pulse.



Change the left 1M/15u to lower values for a shorter time at turn-on.
 

Thread Starter

Taptotweet

Joined Mar 5, 2013
4
So, the pulse starts when 12V is applied?

I guess if you explain the purpose, so many details wouldn't be needed.

There's another thread where I made a schematic for a timed pulse out at power on, it would just be a matter of changing two components to change duration of pulse.



Change the left 1M/15u to lower values for a shorter time at turn-on.
This is exactly what I need! Thanks heaps for your help.

Cheers, Sam
 
So, the pulse starts when 12V is applied?

I guess if you explain the purpose, so many details wouldn't be needed.

There's another thread where I made a schematic for a timed pulse out at power on, it would just be a matter of changing two components to change duration of pulse.



Change the left 1M/15u to lower values for a shorter time at turn-on.

i need this same circuit could u please post the picture again?
 

Reloadron

Joined Jan 15, 2015
7,501
i need this same circuit could u please post the picture again?
Start another thread and define exactly what your objective is. Exactly in detail including voltages and the final objective. It sounds like you want a one shot multivibrator. Thatoneguy last visited these forums in August 2019.

Ron
 
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