I bought an smd buzzer off of Ali (buzzer) and I'm wondering what the reference is to a "normally" hearing person. It doesn't list the frequency, but most state something in 2k or 4k. Regardless, I'm not sure how to interpret "loudness" when buying things like buzzers.
The "loudness" will be used to locate a Frisbie/Disc Golf disc... but I only really need to hear it from about 30feet away. The plan is to use a buzzer, a 433mhz and some undetermined small cpu powering them.
The 'loudness' is a function of the power rating of the buzzer. This should be obvious from the fact that the
reason it is called a buzzer is that it is vibrating, and that means the energy required to move the mass of the
disc determines how much air the disc can push and therefore the sound pressure level and therefore the
loudness. If you want a louder buzzer , get one with a higher power rating. Obviously, if you are putting it
on a frisbee , there is going to be a tradeoff. How large a buzzer you want to use will be based on how
much weight you want to add to the frisbee. Just get a dog and train it to fetch the frisbee.
I'm afraid you'll find it will be trial and error. Assuming buzzers from Ali have valid specifications there are too many other factors to do much with the specifications. Likely the specifications are only good for comparison to other buzzers tested the same way.
Buzzers are most likely directional so you have to consider if the buzzer is moving and what direction it is pointing.
My suggestion is to purchase one or two and see if the suit your needs. At least then you will have a baseline to some specifications.
It's also going to make a big difference whether the buzzer is on top of or under the frisbee after it lands, whether you land on a concrete surface or in vegetation, the ambient noise level, etc.
70 dB is roughly the sound level of a normal conversation. You generally can not hear people talking at such a distance. On the other hand cicadas are definitely way louder than 70 dB and will easily drown out that buzzer (you better stop talking when walking within a few meters of one of those things, as they easily drown out your voice).
I'd start with a buzzer rated 90-100 dB. That may be audible at such a distance, in good conditions. Note that 10 dB is a factor of 10 more power, so I'm talking about a buzzer 100-1,000 times louder than what you have in mind. They're of course a lot bigger, too.
Well, trial and error it is! I didn't know dB could be represented with logX, so that will help!
Well, then that's your homework: read up on dB, what it is, what 70 dB really means, and how sound level changes with distance from the source. Just the basics is enough to give you a very good idea on what to look for and what to expect.
Well, trial and error it is! I didn't know dB could be represented with logX, so that will help!
Not really, because the ear hears volume on a log scale.
Follow up:
Well, I hooked up an attiny, put the 433 on an interrupt, blah blah blah.... End Game: ALL of you are right!!!
This buzzer is no where near loud enough!! From what I learned "sound" drops by 6db as distance doubles. This does seem very accurate as when the buzzer was facing up, I tested at 5/10/20 meters off/on and the sound became very unnoticeable at 20 meters in a forest enviroment. When the buzzer was down (covered by the frisbie), 5 meters wasn't even as loud as 20 meters with the buzzer up... it's bad.
I tried various buzzers and unless you get a 'big' one (in relation to the frisbie), it just won't be lound enough. Then there's the 5v problem for the bigger/louder ones.
Range wasn't great either. At 3.3v, even with a 1/4 antenna, 10 meters seemed to be the limit in "brush" (although I'm a noob so mileage may vary).
Also I learned that water plays tricks on you. When it landed in a creek on one instance, it sounded like it was somewhere it wasn't, but when I physically moved the location seemed to move as well. Luckily I saw where it went in the creek.
Also, power consumption wasn't great either. As a no-nothing in electronics, I put the 3.3v from the battery directly to mosfet (to power the buzzer) with only a 10k resistor pulling it down and the attiny directly connected to the mosfet. At idle, it was pulling ~10ma (during buzzing 130ma... but that didn't matter so much). MOSFET, resistor, buzzer, radio, attiny and coin cell battery... those were all I used (using through hole components, the disc was starting to get heavy). Something about how I connected that mosfet added 7ma, as just the tiny in sleep mode together with the raido only drew 3ma on their own.
I know it's very, very obvious, but you would want these components embedded into the disc, but not really for the reason I first thought. The absolute worse abuse the components suffered was when it hit the "hole". The hole is just a chain lantern that catchs the disc, but depending how the disc hits the hole, the bottom of the disc can rub against the chain. This is something I never noticed before, but it's very concerning hearing the chain rub against the components!!!
IF you purchase your "buzzer" from a reputable distributor, you can select the level of sound output you want.
I had a buzzer left from a customer's build that was inside the enclosure of his product. I used the buzzer/beeper in a project and had to also put it inside the enclosure because it was so loud. Even so, we could hear it go off clear across the factory floor.
Similar devices are motorcycle horns.
Paul
I only heard a noticeable difference when I used 5v and 12v, at 3.3v it really didn't matter. If you have links for loud 3.3v buzzers, please don't hesitate to post them. I've tried 5 models at 3.3v and I stopped at 9x5mm in size, they all seem similar (some hiss more than others, that's about it).
distance
(also referred to as one over the distance cubed or inverse third power of distance)
Here is the Digikey catalog page. go look for what you need.
Paul
This topic was automatically closed 120 days after the last reply. New replies are no longer allowed.
