How can I use opamp or any component for my problem ?

[karekok]

Dear Friends;

I m looking for true component for my problem. In attached file. There is ossiloscope output. and What is my need ?

Could you control and how can i achieve it?

I tried opamp. But I didnt adjust Input offset voltage. Which component is suitable for me?

thanks a lot

regards...
fatih

fatihozturk76@gmail.com

 

[Nigel Goodwin]

Try searching for "555 tutorial".

 

[karekok]

There is misunderstanding. Sorry. I change attached file.
Could you control again please ?

regards

 

[xxxxxxxxxxxxxx]

Yes- more specifically, look at a 555 timer switch debouncer and tell us if you run into difficulties.

 

[xxxxxxxxxxxxxx]

It hasnt changed much.. have a look on google

 

[karekok]

It hasnt changed much.. have a look on google

there are 2 methodes.
1. Opamp Application. But Opamp is sensing 20mV. So Always Opamp is giving High Output.
2. Transistor Application. Transistor is not sensing 150mV It need 1V.

If I adjust Opamp Input Offset Voltage. Maybe I can do it. But How ?

 

[ericgibbs]

there are 2 methodes.
1. Opamp Application. But Opamp is sensing 20mV. So Always Opamp is giving High Output.
2. Transistor Application. Transistor is not sensing 150mV It need 1V.

If I adjust Opamp Input Offset Voltage. Maybe I can do it. But How ?

hi,
You can use a comparator to detect the difference in the voltage levels.

The comparator can be configured to give a TTL output level whenever the signal is greater than say, 50mVolt.

A fast comparator will give TTL pulses each time it senses greater than 50mV,
so you could use a simple resistor/capacitor filter to remove the comparator output 'spikes' or allow the high output edges to re-trigger a monstable to give a clearer pulse.

Do you know how to do that?

 

[karekok]

hi,
You can use a comparator to detect the difference in the voltage levels.

The comparator can be configured to give a TTL output level whenever the signal is greater than say, 50mVolt.

A fast comparator will give TTL pulses each time it senses greater than 50mV,
so you could use a simple resistor/capacitor filter to remove the comparator output 'spikes' or allow the high output edges to re-trigger a monstable to give a clearer pulse.

Do you know how to do that?

Dear Eric;

Thanks for useful informations. How can i use comparators. I dont know.

Could you prepare simple circuit for me?. I can try something with your circuits or Which comparators is suitable for me ?

many thanks for your time.

 

[karekok]

... editted. ( because of dual message ) by karekok

 

[ericgibbs]

Dear Eric;

Thanks for useful informations. How can i use comparators. I dont know.

Could you prepare simple circuit for me?. I can try something with your circuits or Which comparators is suitable for me ?

many thanks for your time.

hi,
Get the datasheets for the LM392 and LM393 from www.datasheetarchive.com

Study the data sheets and try to follow the application notes, post a simple drawing on how you think they would be connected
and we will help you thru it.

 

[Hero999]

You might also want to add a low pass filter on to the input of the comparator to get rid of those nasty high frequency harmonics which might cause it to switch on and off very rapidly.

 

[karekok]

You might also want to add a low pass filter on to the input of the comparator to get rid of those nasty high frequency harmonics which might cause it to switch on and off very rapidly.

dear friends ;

thanks a lot for your time. . I m just trying L272M Opamp. Input Offset Voltage is 15mV. May It will work. I can try Low pass filter with opamp.

regards...

 

[ericgibbs]

dear friends ;

thanks a lot for your time. . I m just trying L272M Opamp. Input Offset Voltage is 15mV. May It will work. I can try Low pass filter with opamp.

regards...

hi,
If you use the L272 as an amplifier it will not give give you what you want, it will just amplify everything!

If you must use the L272, configure it as a Comparator.

 

[Hero999]

But as the signal is so small he really needs an amplifier before the comparator to ensure reliable operation.

He also wants a precision rectifier to remove the negitive before the low pass filter.

This isn't as simple as everyone first thought.

 

[Nigel Goodwin]

This isn't as simple as everyone first thought.

It's not even simple to understand what he wants?

 

[audioguru]

I dont know.

Comparators are simple. Look at their description in Google then use one.

 

[Roff]

It would really help to know what the time scale is, and the carrier frequency. It looks like simple AM digital data.

 

[ericgibbs]

But as the signal is so small he really needs an amplifier before the comparator to ensure reliable operation.

He also wants a precision rectifier to remove the negitive before the low pass filter.

This isn't as simple as everyone first thought.

hi,
A Comparator will easily detect the difference in levels between 20mV and 150mV, it dosn't need an amplifier. Just set the Vref at about 80mV.

It also dosn't need a rectifier, just a simple RC filter on the comparator output

 

[karekok]

hi,
A Comparator will easily detect the difference in levels between 20mV and 150mV, it dosn't need an amplifier. Just set the Vref at about 80mV.

It also dosn't need a rectifier, just a simple RC filter on the comparator output

please give me circuit schematic with L272M as a comparator between 20mV -150mV . So I tried some comparator circuit. But No answer.

 

[ericgibbs]

hi,

Tell me what the 'p1' , 'p2' time periods are, also the frequency of the spikes, refer the gif drawing.

Then I will try to help.