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Op amps

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Pastor Del

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At what voltage on AR3B pin 6 should I expect AR3B's output (pin 6) to go low? I'm getting almost 6V on pin 3 before the output goes low. Changing AR3 does not fix it.
upload_2015-9-14_13-38-5.png
 

kubeek

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The output pin 7 should go low when input 6 is higher than input 5. If the change happens at 6V, then I gues the 5V input is not what it says.
 

kubeek

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Did you check the supply for that comparator? Can you show the rest of the circuit?
 

Les Jones

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What is the supply voltage (On pin 8 of the TLC393) ? I think it needs to be at least 2 volts more than the 5 volts input to the comparator.

Les.
 

AnalogKid

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According to the schematic there is 160 uA flowing through the opto when AR3B pin 7 goes low. We can't know what the opto is doing, but that's almost certainly not enough.

There is no pin 3 on the schematic.

ak
 

MikeMl

Well-Known Member
Most Helpful Member
'393 is not rail-to-rail Input.

393.gif
 
Last edited:

ronsimpson

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So you want to know of the input is above or below 110 volts. Did the math in my head so it might be wrong.
I connected up the supply(s).
There should be a 0.1uF cap across the 10V. (some cap)
1k resistor is for about 9mA in the opto isolator.
upload_2015-9-14_18-11-3.png
 
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