Understanding Resistance...:S

Forum 2005-2010 (read only) General Frequently-Asked Questions
1

I am using a piezo buzzer on my arduino and need some advise on resistance. Basically, can I use a resistor as high as 10KOhms to reduce the volume of the buzzer?

I understand that resistors are required to stop too much current being drawn but is it also bad for the arduino if there is too much resistance?

I have done some reading on Ohms law and I can do the calculations but there are still many grey areas for me.

Thank in advance,
Tom

2

Basically, can I use a resistor as high as 10KOhms to reduce the volume of the buzzer?

That depends on the buzzer's ratings. Do you have a datasheet?

I understand that resistors are required to stop too much current being drawn

That's is correct.

is it also bad for the arduino if there is too much resistance?

No. In fact, if you write a pin to HIGH when it's not connected to anything, electricity is still flowing (through near infinite resistance).

3

Here is the buzzer: http://www.coolcomponents.co.uk/catalog/product_info.php?cPath=50_75&products_id=341

I am a strong programmer, software engineer by profession, but I am just starting out with electronics.

I used a 220Ohm resistor to first test the buzzer but on discovering it was ear piercingly loud I moved to a 10KOhm and its perfect volume but just wanted to be sure I am OK to do this.

Cheers,
Tom

4

but just wanted to be sure I am OK to do this.

Yes it is fine you can put what ever value you like in series with it.