Extra protection for arduino analog pins from over voltage

[boylesg]

I have been reading that it is possible to add a 5.1V zener diode and a 220R resistor to the analog pins to provide extra over voltage protection.

It there any reason why you couldn't use a 'rubber zener' / 'Vbe multiplier' in place of the zener diode?

 

[Electro nS]

i donot know what is a rubber zener and its price or availability or why its used or not !

but google : Ruggduino . it contains all the protection you can dream of for an arduino with schematics.

cheers

 

[boylesg]

i donot know what is a rubber zener and its price or availability or why its used or not !

but google : Ruggduino . it contains all the protection you can dream of for an arduino with schematics.

cheers

A 'rubber zener' or 'Vbe multiplier':

**broken link removed**

They are normally used to bias class AB amplifiers but I am wondering if I might use one to protect an arduino pin.