Protection for Arduino (overvoltage)

Other Hardware Sensors
1

Hi
I am receiving a bipolar signal to the Arduino. This is done through a LM741 (op-amp) and seems to be working very nice. The question is how do I go about limiting the signal – what I mean is if the op-amp is destroyed or if something else happens to the circuit, how can I secure the Arduino so it does not receive anything else then 0-5V? The signal will change quickly and it is important that i dont loose any resolution.

I thought about doing it like this:

The diode is to protect against negative Voltage and the zenerdiode is to ensure the Arduino wont get more then 5V........ Will that fly?

Thanks

signal til arduino 21-06-2013.png
signal til arduino 21-06-2013.png702×380 3.58 KB

2

Actually,If you are using a UNO R3, it already comes with a voltage regulator.
Otherwise do no go for a LM317,instead opt for LM7805,whose input should be a 9V transistor radio battery and comes a 5V as regulated output.In this case your arduino is safe even if your regulator blow,but blowing off is a less frequent issue,just relax and have fun.

3

somanshumehta I think MrBear may be talking about an input pin not VIN if so I think a zenar diode would be appropriate.