My project includes a piezo buzzer. Right now, I have connected a 100 ohm resistor in series with the piezo buzzer. The sound is OK, but I'm wondering if I can go louder without burning out the arduino uno pin (pin in question is Pin 9). It is a medium size piezo buzzer.
I mean, can't I just remove the resistor? Hypothetically, a piezo buzzer can only draw so much current. Is that right?
Active piezo (works with a DC voltage), passive piezo (needs a tone, e.g. from the tone library),
mechanical DC buzzer (sellers call this also 'piezo'), or mechanical passive (speaker).
Better post a link to the 'piezo'.
Leo..
If it is working now, what voltage are you using on the resistor end? Does the buzzer have a + sign toward one connection? If so it has the electronics inside to make the tone. Some piezo buzzers are made to go inside a sealed enclosure and are really loud otherwise. You can get them for just about the loudness you require.
Paul
larryd, that circuit is for a passive buzzer.
OP might have an active one.
Leo..
Wawa:
Active piezo (works with a DC voltage), passive piezo (needs a tone, e.g. from the tone library),
mechanical DC buzzer (sellers call this also 'piezo'), or mechanical passive (speaker).
Better post a link to the 'piezo'.
Leo..
It has a dot sign to indicate the positive side. It's a little bigger than a 50 euro cent. I think it is 30mm in diameter. It is similar to this one.
I have powered it from 5V output from Arduino uno. 5V goes to the positive side of piezo buzzer through a 100 ohm resistor and the negative side goes to ground.
arduinoware:
It has a dot sign to indicate the positive side. It's a little bigger than a 50 euro cent. I think it is 30mm in diameter. It is similar to this one.I have powered it from 5V output from Arduino uno. 5V goes to the positive side of piezo buzzer through a 100 ohm resistor and the negative side goes to ground.
If that is the case, then no resistor is needed.
Paul
arduinoware:
I have powered it from 5V output from Arduino uno. 5V goes to the positive side of piezo buzzer and negative side goes to ground through a 100 ohm resistor.
So it makes a sound if you just connect it to 5volt and ground.
Then it's an active (piezo) buzzer.
That link lists a 3mA current draw.
If true, then lowering/removing the resistor is not going to make it significantly louder.
Mechanical buzzers are usually louder.
But there is a lot of spread between them, and the sound is not as 'clean' as a true piezo.
As Paul has suggested, I would try to increase sound level by putting it in/on an enclosure.
Leo..
Actually, I had to put the piezo INSIDE an sealed enclosure because it was so loud you could hear it clear across the plant, with equipment running. It was surplus from stuff we built several years ago, and was designed to be heard when it was placed inside the machine we built.
Paul
The 17mm passive piezos I have used with the toneAC library (twice the drive voltage) were not very loud, even after fiddling with the frequency.
From the mechanical buzzers I use (hundreds of them) I put ~5% straight in the bin.
Only 5% is very loud, the rest is ~ok.
Only the real piezos are consistent in volume.
Leo..
