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View Full Version : How to create bursts using single NE555



mohitkhanna3v_infinate
06-30-2008, 07:36 PM
This is the same as the last post I posted in the same sensors forumn
http://www.roboticsindia.com/modules.php?name=Forums&file=viewtopic&t=3362
But I didnt get reply for that, so im posting this as a new topic. May be as a new topic, it would be useful to others also who are new as me.


"
Ive seen in some forumn here on roboticsindia a method of creating bursts. In it its said to create frequency using 1st 555 n then use 2nd 555 to create bursts by connecting it to the reset of 1st.

Is it not possible to create bursts using just 1 555? Im able to produce arnd 38kHz frequency, and TSOP is responding to it well for a few miliseconds. Not with continous signals. Reading the datasheet, and other Qs here, I feel its definately so due to lack of bursts. So all I need is to create bursts using same NE555

Im insisting on using same NE555 as ive just 1 NE555 at the moment and Market is closed tomorrow, so just wishing that I could do the sensor part of my project by tomorrow.

In case its not possible to do it using just 1 NE555, then please can you give me circuit diagram of producing bursts? And how would we define that after how many cycles we need burst and equvalen to how many cycles. As i read in some post here that we require approx 14 cycle burst after 10 cycles. I cant figure it out easily from the datasheet.

And can you explain me what exactly we mean by the term duty cycle.

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groover
08-24-2008, 09:13 PM
hai...
i am currently working on IR enterfacing.... hope it works ..
anyways i will definately share my experience ..... and by the way i am
not understanding what u mean by burst
but i can explain duty cycle.....it is the percentage ON time to the total
cycle period i.e ON time + OFF time

........