Electric bell/horn to replace ding-ding and AirZound?
 

Hello

I like the sound of ding-ding bells because it's not agressive and pedestrians know that a bicycle's coming, but I also sometimes need a horn like the AirZound.

So instead of using two different devices, I'd like to use a battery-powered bell/horn.

There are plenty of electric bells on eBay or Alibaba, so I was wondering if someone could recommend a brand + model that plays those two sounds.

Thank you.

i like this. very loud gets attention. i use short blast. if thet ignore me or won't move then i lean on it alittle more. that usally works.

http://www.amazon.com/Worksman-Cycle...d=H2UCCN0FQSDP

Thanks but I also need a soft sound for pedestrians to replace the ding ding bell, and that 105dB horn gets mixed reviews.

Is there no two-tone/two-volume battery-operated bell?

The electric horns are nowhere near as loud as the AirZound.

Yes, they seem to be around 70-80dB.

But then, I don't need a 105db like the AirZound and such, even out in the country.

How loud is a car horn, which definitely does the job?

I think there are two elements at play: one, whethere the sound is going to be loud (or piercing) enough to be heard a few meters ahead of your bike, with parks, traffic, and countryside having different levels of noise in each environment; and two, the nature of the sound the horn emits, with car-like horns being more likely to elicit the right behavior (get out of the way), and bike-like horns being more likely to be ignored (just a small, slow-speed vehicle coming).

I think the challenge is to find a device that has different sound levels (e.g., countryside, park, traffic), and different tones (regular bell, car horn).

The frustrating thing is that the technology is all there: there are electronic bell that simulate a siren, an emergency vehicle horn, a cell phone beep, etc. No manufacturer seems to have put the right tones and noise levels together in one device yet.

Right. Someone good at electronics should add an entry in Kickstarter and start a business :-)

I would put two big buttons: quiet and loud.

Go to AutoZone. Pick up a car horn, a button and a horn relay. Pick up a small 12V lead acid cell from eBay. I have one that fits easily with the relay into a small under-seat tool bag with room to spare. Wire it up, enjoy. The whole thing cost me about $45.

I don't know if anyone has tried these but if you do let us all know how they work.

http://truebicycles.com/contents/en-us/d15.html
http://www.sjscycles.co.uk/buddy-meg...orn-prod15535/

Replace the 12v lead acid battery with a 4s LiPo pack -- 2000 mAh should be more than enough -- make it a good deal smaller.

3s might work as well, but I imagine 4s would work better.

(Of course, you'll need a charger for this battery, but you'd need a charger for the lead acid battery too if you didn't already have one.)

Thanks for the infos. I have a few questions before going ahead:

• what tools would I need (I know nothing about 'tricity, but could find someone knowledgeable to help)?
• how big would 3/4 LiPo batteries be?
• how safe are they to use on a bike?
• how much power would a car horn use for this purpose, so that I have an idea of how often I'd have to recharge the batteries?

Tools would be nothing more than a soldering iron and wire cutters, though you would also need a LiPo charger.
I've got a 2200 mAh 4s pack right here ... it's about 3.5" x 1" x 1". It cost $17 from hobbyking.com.
It's hard to be precise about how much power a horn would use, as they vary. You can look at the fuse in a car for an upper limit, but they should use a lot less than that.
However, assuming that a horn would use 10 amps, a 2000 mAh (2 Ah) pack would power that for 2 Ah/10 A or twelve minutes. Considering that a horn is usually only used for a second or two at a time, that would last a while. (I don't think an Airzound lasts more than a minute.) 10A on this battery corresponds to a 5C discharge rate -- which is much lower than what these batteries are typically rated for.

Do make sure you recharge it before it gets too low (like after ten minutes of use) or you'll reduce your battery's life.

As far as being safe on the bike, physical damage can cause them to burn. If you hit them with a hammer or something, they can catch fire (for a small battery like this, it's a small fire, but of course it can catch other things on fire). Overcharging can do so too. So in a crash, if the battery is crushed, that would be bad, but on your bike it's not a major concern as you just disconnect it's bag and throw it in the street and let it burn. A bigger concern would be in your house if you set the charger wrong. They do sell fireproof bags for charging LiPos -- they're a good thing to have.

Note that while a lot has been made of this, most batteries have similar concerns. If you crush a lead-acid battery, it will leak acid, and if you overcharge it, it will vent hydrogen gas which can explode. If you crush a NiCd or NiMH battery, it will internally short out and can get hot enough to start a fire though it itself doesn't burn so that helps. The danger is small, but it does exist if you're not careful.

Thanks a lot for the feedback. I find it odd that no company has come up with such a product.