Would this work with a MAX 186 Chip Looking for Info and Feed Back if this wil

sam_sam_sam

Would this work or something like it







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Sam

Post Edited (sam_sam_sam) : 11/26/2009 7:26:02 PM GMT

kwinn

No.

First, 5 5V zeners add up to more than 24V so the output voltages would be 0 or the result of leakage current only.

Second, the input voltage to the chip can only exceed the supply by 50mV, so even if the input voltage was higher (say 26V) so the zeners conducted all or most of the input voltages exceed the range of the ADC and would damage the chip unless the resistor to the input pin was high enough to limit the current to a value the protection diodes could handle.

What exactly are you trying to accomplish?

sam_sam_sam

kwinn· or any one else

This what I want to is make Voltage latter that the max186 can read

0 to·12· one range in··· >>>>>>·· 1.25 steps
·then
12 to 24· second range· >>>>>··· ·1.25 steps

volts for a nicad charger

Do you have any ··how I might be able to this

Thanks for any help that you can give me in this matter

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··Thanks for any··that you may have and all of your time finding them

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Sam

kwinn

Not sure what you mean by 1.25 steps, but is this what you had in mind?

Channel 0 would read 0-4096 for a 0 - 12V input (3mV per bit)

Channel 1 would read 0-4096 for a 12 - 24V input (3mV per bit)

The 50K pot could be adjusted to read 10mV per bit so the only math would be shifting the decimal and adding the 12V for the 12-24V range.

sam_sam_sam

No

1.25 pre channel· stepping up to 10 volts· to 12 volts· Setting One

I want to charge 8 batteries in series and watch·each· battery's voltage·in each channel of the Max CHIP·and watch the·charging votlage and if
any channel gose above pre set value then slow charging rate so that voltage gose down to a safe value

2.50 pre channel· stepping up to 20 volts· Setting Two this is a maybe· because it would have··to watch two batteries at one time

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··Thanks for any··that you may have and all of your time finding them

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Sam

Post Edited (sam_sam_sam) : 11/27/2009 2:58:23 AM GMT

kwinn

So you have eight 1.25V batteries in series and you want to monitor the voltage of each one to control the charging rate.

The attached circuit should work. If you use the resistor values shown channels 3-5 readings need to be multiplied by 2, and channels 6-7 need to be multiplied by 3.

You could also substitute a zener diode for the 50K and 100K resistors. A 3.75-4V zener for the 50K and a 7.5-8V for the 100K. The readings for channels 3-7 would no longer need to be multiplied, but the zener voltage would have to be added to each channel.

sam_sam_sam

kwinn

I will give this try with the A··....>>>>> ·3.75-4V zener for the 50K and a 7.5-8V for the 100K. The readings for channels 3-7 would no longer need to be multiplied, but the zener voltage would have to be added to each channel.



Thank for your help in this matter

One note on the ICL board I am still working on that board


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··Thanks for any··that you may have and all of your time finding them

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Sam