Gentlemen,

i am student of electrical engineering B.Sc.(3rd year).

instrutor has assigned us SAMPLE AND HOLD project , without given us any information. so please help me in this project ,with brief discription about this project and project components.

i have little idea that we may us FET as switch(will help in sampling of signal and we will give it two inputs: one is under observtion signal and other is square wave as impluse for sampling). For holding we will use ,a capacitor.

so these all was my unrefined information . so please help me with some simple report and project circuit of SAMPLE AND HOLD.

WITH BEST REGARDS,

goldig,

 

So you want us to do your work for you.. yeah, that's not going to happen. Why dont you try and develop a sample & hold system and post on this forum with questions. Otherwise, don't waste peoples time asking for a free handout.

 

Sir, you have confused your impression. I have defined my ideas about SAMPLE AND HOLD project. So i was expecting some approval and comments on it.
So reconsider on your answer ,and have some valid comments.
Thanks,
Goldig

 

Post a schematic if you want feedback.

__________________
Ron (aka Rube)

 

Hi Goldig,

You have received a negative response because you have not posted what you think the circuit solution may be?

Members like to feel that the OP has already done some work on finding the answer himself.

There are numerous ways of making a 'sample/hold' circuit and it would take too long to cover all the combinations.

Can you give more details of the type you require and what voltages/rates etc.

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

Hi Goldig!

This is my impression: as far as I know a FET and capacitor are needed (or at least popular) for a basic sample-and-hold, as well as a high-input-impedance follower to keep the cap from discharging too fast. I presume you don't mean sample-and-hold in the sense of a sampling keyboard or something--that's a whole lot more complicated.

Without knowing details of what you're trying to do I wouldn't want to try to guess what else to tell you, except that you could use an opamp with FET inputs after the cap for the high-impedance follower, and its output is the circuit output. From what I'm reading here, large values are better for the cap as long as it's small enough to charge properly at the frequency you're sampling at.

Section 4.10 in Art of Electronics (Horowitz and Hill) gave me this information. Hope you have a library! And I'm a hobbyist, not an electrical engineer, so if you define your needs more clearly I'm sure others here can help more.

As Eric asked: post your working schematic, voltage and current requirements, and what research you have done so far, and you'll probably get more positive responses.

Good luck,

Torben