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Author Topic: Subtracting a constant voltage from an input voltage  (Read 14068 times)

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Offline BurnedResistorTopic starter

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Re: Subtracting a constant voltage from an input voltage
« Reply #25 on: October 26, 2016, 08:38:01 pm »
Helps to attach a file  |O
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Online Ian.M

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Re: Subtracting a constant voltage from an input voltage
« Reply #26 on: October 26, 2016, 08:54:49 pm »
Its hitting the -ve rail hard.  Simulate it again with +/- 15V supplies to the LT1881, then use the principle of Superposition on sources V2 and V3 to understand WHY its hitting the -ve rail when operating with a 5V single supply. 
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Offline dannyf

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Re: Subtracting a constant voltage from an input voltage
« Reply #27 on: October 26, 2016, 10:41:49 pm »
A summing amp does what you want.
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Offline strawberry

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Re: Subtracting a constant voltage from an input voltage
« Reply #28 on: October 27, 2016, 12:00:14 am »
Rail-to-rail op amp
zeners are not good for frequencies
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Offline Smokey

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Re: Subtracting a constant voltage from an input voltage
« Reply #29 on: October 27, 2016, 12:46:29 am »
Lots of good circuits here.  As I read through you guys already ticked off all of the ways I was thinking of.  Fun!
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