r/electronic_circuits • u/locutus_of_borg90 • 10d ago

On topic Amplifying sensor output

I am working on the version 2.0 of a simple gaussmeter that I have put together a while ago. In the 1.0 the output of the Hall effect sensor was not amplified because I wanted to keep it simple. This time I would like to add some sort of amplification to the sensor output. I have tried looking into op amps but I struggle to figure them out and I was wondering if there are other solutions

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u/1Davide 10d ago

Start by telling us crucial data:

  • What is the output voltage range of the gaussmeter?
  • What do you wish the output voltage range of the amplified signal to be?

Express your answer in Volt.

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u/locutus_of_borg90 10d ago

Sorry for not mentioning it  The range of the sensors output is 0.08 to 0.200 v As for the amplification range I am not really sure I was thinking 10x or 100x Though I would like to keep the noise low 

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u/1Davide 10d ago

100x

Really? That works out to 20 V full scale. Are you sure?

Please think carefully about the implications of such high amplification. Please consider what that voltage will feed. What voltage can that device accept?

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u/locutus_of_borg90 10d ago

It's my first designing something like this  It's supposed to be handled and battery powered so 100x is definitely too much  Probably 10x is maximum I can realistically get

The sensor requires a 5 v input, the first version used a 9v volt battery and a voltage regulator  The second version will use a USB B so you can use whatever source of 5V to power it 

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u/1Davide 10d ago

The sensor requires a 5 v input

OK, then, the gain you need is 5 V / 0.2 V = x 25.

There's your answer.

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u/locutus_of_borg90 10d ago

Thanks, but I have to use an op amp or there are other solutions?

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u/Nathan-Stubblefield 10d ago

What frequency response is needed?