hi I'm a new member here

I need advice about how to manage a ADC0808 as a general ADC IC
because i have a final task to make a teaching aid for mcs51 using ADC0808
as i know ADC0808 has several input and output.

I still can't put it general enough i even confuse when reading the data sheet

please be patient when help me
thank you

 

hi,
How many channels on the ADC do you want to use.?

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if possible i want it all
I need to make it as general as it is

but first may be i only need one
i need to convert form LM 35 temperature sensing
to binary
as first trial that's good enough

 

hi,
Ok, I'll post a circuit tomorrow.

A point to understand is that the LM35 is 10mV/Cdeg, so that means a max of 1V at 100Cdeg.
The ADC is 8bit [255] so the resolution will be about 1Cdeg.

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it's correct
the LM 35 have resolution 10mv/cdeg and max 150 c deg, so it will be 1.5V.
thats why i use OpAmp to aplify it to 5V

but since I didn't know the limit current for LM 741 noninverting input and the max output current of LM35 I only use a potensio at the output of LM 35 before input noninverting in LM741.

these circuit suppose work in proper, after i find out the ideal resistance to sync LM 35 with LM 741 I 'll definitly exchange the potensio with fix film resistor, later.

Thanks for the support
it worth much for me

 

What power supply voltages will the 741 have.?

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Eric " Good enough is Perfect "
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I use ordinary two Power supply with +15 1 A and -15V 1 A

 

I use ordinary two Power supply with +15 1 A and -15V 1 A

did i need to increase the current supply?

 

hi,
Power is OK.

Look at this datasheet, pages 12/13, it gives a number of MCO to ADC examples,

Attached Files

AN-247.pdf (591.9 KB, 7 views)

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Eric " Good enough is Perfect "
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thanks for the pdf
i'll take my time to read it first