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Okay so I'm a beginner at electronices not sure where to begin looking so I'm just going to ask, is there a way to maintain voltage at 5V but it must be able to change to below 5V.

Basically, I'm hooking up an output from a sensor and going to connect it to an Arduino for data logging. But the problem is the output from the sensor can go up to 7V or more(According to the a program that monitors the sensor, it doesn't do data logging), and i wish to avoid frying the Arduino board so is there a way to fix that?

Will a voltage regulator do it? All I know about voltage regulators is it maintains voltage at a certain point.

So to make it clearer, is there a way to prevent the output voltage of the sensor from shooting above 5V and also be able to change from 0V to 5V.

Ignacio Vazquez-Abrams
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Amos
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  • Scale it using an amplifier. – Eugene Sh. Aug 12 '16 at 13:50
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    If you're lazy and just want to cut of any reading above 5v, just use a zener diode and an appropriate resistor with it. That means cutting off anything above. – Bradman175 Aug 12 '16 at 13:53
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    Actually a simple voltage divider can do, depending on your hardware – Eugene Sh. Aug 12 '16 at 13:56
  • @Bradman175 - Oh yeah. That should work. Just want to block off any voltage above 5V thanks. – Amos Aug 12 '16 at 13:58
  • @Amos You familiar with how to do it? Or you could follow Eugene's way and scale everything down with an equally simple voltage divider. – Bradman175 Aug 12 '16 at 13:59
  • @Bradman175 - I think so. Im more familiar with using a zener diode than using an amplifier – Amos Aug 12 '16 at 14:00
  • Well, if you just want to clamp it will be fine. – Eugene Sh. Aug 12 '16 at 14:01
  • @EugeneSh. - Erm. Not sure how to clamp it, but interested to know how to scale it with an amplifier – Amos Aug 12 '16 at 14:02
  • @Amos Two ways to scale it. Simply use 2 resistors configured as a voltage divider or use an amplifier. I know the Amplifier is better but more complicated but I'm not familiar with the "specs". I can show you how to clamp it. – Bradman175 Aug 12 '16 at 14:05
  • @Bradman175 - About the clamping part, you dont need to do it. But thanks for the suggestions. Ill go try it out, but ill most likely stick with the zener diode, being the easiest to do i think... – Amos Aug 12 '16 at 14:08
  • @Amos But this is a Q&A site. I have to show that this question is answered by actually putting an answer. This is only the comments section :P – Bradman175 Aug 12 '16 at 14:09
  • @Bradman175 - I know :3 But my question has been kinda answered in the comment section. – Amos Aug 12 '16 at 14:10
  • @Amos So ill move it to the answers section. – Bradman175 Aug 12 '16 at 14:11
  • @Bradman175 - Okay sure. Ill mark it as answered from there then. – Amos Aug 12 '16 at 14:11

2 Answers2

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There are 3 ways you could achieve restricting the voltage from going over 5 volts.

  1. You could clamp it by using a zener diode at 5V along with a resistor to restrict too much current going through the Zener diode. See this.

enter image description here

  1. You could use a resistor voltage divider to scale the output from the sensor to make the maximum voltage at 5 volts. But make sure you know the sensor's output voltage will not reach over than what you predicted. To prevent something like this from destroying your target device, add a zener voltage clamper at the output.
  2. Use an operational amplifier
Community
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Bradman175
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Use a simple voltage divider. Find rhe maximum voltage from the resistor and choose the resistors according to that.

It is better to choose the resistors in such a way that the maximum outout will be scaled to 4v, just as a precaution.

Go for the option with zener only if there is a possibility of drastic change in output voltage

Sanu - Open Maker
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