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[on:]

I've used this little buzzer from Sparkfun, but it's not very loud.  It works using the tone function.
https://www.sparkfun.com/products/7950


I'm wondering if anyone could tell or would know if this one is louder?  http://www.digikey.com/product-detail/en/AI-3035-TWT-3V-R/668-1204-ND/1745457?cur=USD
The datasheet says 100dB @ 3V, 10cm.  And does this one work off the tone function, or do I just supply it with 3 volts?  Looking at the data sheet on it, it seems I just supply 3 volts.  I'm hoping to find a fairly loud buzzer to alert a me if I'm starting to max out my motor speed on a segway, so the rider can know they're fixing to fall over if they don't slow down.

[Reply #1 on:]

What do you have for a power source? Digikey has some pretty loud ones - 115dB, 125dB

http://www.digikey.com/product-search/en/audio-products/buzzers/720967?k=piezo%20buzzer&ColumnSort=-397&fid=0

A speaker and MOSFET driven by tone output can be quite loud too.

I use this one in my fencing scoring machines
http://www.mpja.com/prodinfo.asp?number=14618+SP

with this amplifier, the switch on the left allows for 2 different load resistors for attempted volume control - my wife says both are too loud

[Reply #2 on:]

Thanks, Crossroads,
My segway is powered by 24V, but I only have 5 volt coming onto my control board (supply from Sabertooth motor driver).  I'm hoping to find one that is loud enough, but is PCB mountable, I like cutting out extra wires anytime I can.
It will, however be in a plastic enclosure, at my feet, like this:


I wonder if this one would be loud enough to be heard? http://www.digikey.com/product-detail/en/MAS803Q/458-1257-ND/1957907   It probably would.  It says continuous, does that mean I just have to turn it on, or do I have to give it PWM?  It say 1.5 to 6 V.  I'd give it 5 volts. I have some of these. http://www.digikey.com/product-detail/en/MMBT3904/MMBT3904FSCT-ND/458971  Would this work to power it?
Thanks

[Reply #3 on:]

First one says "Indicator, Internally Driven", so just DC on should make it noisy.
Needs up to 130mA tho, so transistor control is needed.
The '3904 should work, make sure you leave a way to put a heatsink on it.

[Reply #4 on:]

heatsink...  HMM, this one I was thinking of is SMD, tiny.
Maybe I need a bigger one, so I don't need a heatsink.  The buzzer only uses 130ma...

[Reply #5 on:]

"The useful dynamic range extends to 100 mA as a switch"
I'm thinking a higher rated part might be better.
The datasheet charts only show performance up to 100mA.
130mA? Who knows.

[Reply #6 on:]

Oh yeah,  I remember now.  I'm still catching on to these transistors and MOSFET's.  I need one that's rated well over what I'll actually be using in current.
This one should work well.
http://www.digikey.com/product-detail/en/DMN3404L-7/DMN3404LDICT-ND/2052805

[Reply #7 on:]

That's a magnetic buzzer and not a piezo buzzer. Before anything else, you might try
coupling it to the Arduino through a 10-uF cap, and wiring a 1N914 diode across the
buzzer terminals, anode to gnd. They also sometimes get louder if you put a piece of
black electrical tape over the hole. After that, you need more current drive, as Bob says.

[Reply #8 on:]

Smoke alarm buzzer!

The ones inside these things are really loud and a wimpy 9vdc seem to have enough current to drive them.

http://ecx.images-amazon.com/images/I/41vOLU-588L._SL500_AA300_.jpg

Lefty

[Reply #9 on:]

have you allready considered teckel's toneAC lib? - http://arduino.cc/forum/index.php/topic,143940.0.html -

[Reply #10 on:]

Smoke alarm buzzer!

The ones inside these things are really loud and a wimpy 9vdc seem to have enough current to drive them.

http://ecx.images-amazon.com/images/I/41vOLU-588L._SL500_AA300_.jpg

Lefty

Beware of radioactive sources in ionizing types. May be anything up to 120 db at 1m

each 6db (aprox) is twice as loud - check the distance at which measurements are taken.
http://www.sengpielaudio.com/calculator-distance.htm

I used to make bespoke sounders for the military (supposedly 240db although I quoted then as "very loud" as my meter went off scale), they made your face hurt when testing through ear defenders. Highly illegal in the UK. My neighbours would ask, did you hear that damn alarm again yesterday? Nooooooo

[Reply #11 on:]

You probably know, but you can drive each side of a piezo sounder in anti-phase to get more umph!

[Reply #12 on:]

Before I order one of these buzzers, does this schematic look like all's well?
The buzzer is:
http://www.digikey.com/product-detail/en/MAS803Q/458-1257-ND/1957907
The SMD N-MOSFET is:
http://www.digikey.com/product-detail/en/DMN3404L-7/DMN3404LDICT-ND/2052805

The buzzer is 6 VDC, but thats 105dB, so 5 VDC should be loud enough to hear thru a sealed Hammond enclosure.
Thanks

[Reply #13 on:]

I would add a series resistor from D8 to the gate to protect against gate capacitance charge/discharge.

[Reply #14 on:]

I would add a series resistor from D8 to the gate to protect against gate capacitance charge/discharge.

OK.  Like a 330ohm or a 1K?  I'm slowly learning about mosfets.  I think the 1K would make it turn on slower?  ...but in the case of a buzzer, it shouldn't matter.