Running horn from cycle analyst aux power tap

Topic pretty much sums it up. Can i run a simple motorbike horn from the auxiliary power tap on the cycle analyst? Gut feeling tells me it will pull way more than the 0.5amps the tap was designed for, but since its short bursts maybe it will be fine? So what do you guys think?

I have version 2.3 if that makes any difference

It depends on the horn, but they draw anywhere from 3 to 10 amps. So, No. it won't handle it. You'll need a DC/DC converter.

Not a good idea regardless of the power draw. These are like auto horns - basically a big primitive buzzer - a massive inductor doing high current mechanical make/break at the audio frequency. This will send huge noise spikes right to the CA circuit board.

Ok then, time to se if i can mount that pesky buck converter.. Should have asked before i did all the wiring. Ah well glad i asked before a damaging test was performed. Thanks guys.

AFAICR that power tap is at pack voltage, so if you are running at above 15V I don't know what that would do to the horn (assuming it's from a 12V system like most would be). I have no idea what that would do to the horn--but even if the horn has no problem with it, you would need a horn *button* (switch) that can take the pack voltage at the current necessary, so it doesn't just burn/arc the contacts.

I'm using automotive horns on my CrazyBike2 and they run off a separate 12V battery right now (my present DC-DC can't provide enough current).

Observator said:

Ok then, time to se if i can mount that pesky buck converter.. Should have asked before i did all the wiring. Ah well glad i asked before a damaging test was performed. Thanks guys.

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Depending on how easy it is to tap your battery, you may wish to just run a dedicated power/gnd straight to the pack. By running the wiring directly to the pack (nothing shared with the electronics), the battery squelches all the electrical noise. Unless you need Anger Management, you won't use the horn much and an occasional blast will draw no significant power- little danger of unbalancing the pack. This avoids over-specing a DC/DC converter for an occasional toot and dealing with the nasty inductor effects.

I run a 12v Fiamm Freeway Blaster (6A) auto horn on a dedicated 4 cell (13.2v) tap on my 20s pack (pack has a block of 4 PP connector). This approach is not a good plan for general 12v stuff (lighting) but a long 5 second blast with a 6A horn costs only 6A x 5sec / (60sec/min) / (60 min/hr) = 0.008 Ah - not much imbalance

BTW - most buzzer/diaphram-type car horns and motorcycle horns like to be mounted on a short length of springy steel strap so the body of the horn can resonate naturally. Bolting the horn body firmly to something rigid cuts the volume immensely. Anyhow - something to look into....

Ended up installing the buck converter before i saw your tip. For my current battery setup it wouldn't be very practical getting at just 4 cells, due to running 6s packs. Your however right about the imbalance created being negligible, might incorporate the idea in a future iteration. Thanks for you input.

Maybe a bit offtopic, but I just bought a battery (2 aaa's) powered horn, a little pricey but it promises 130dB at one metre, which is a jet engine (or an ACDC live concert) from 1 metre. It was pricey ($30) but I thought a good idea given I bike through the winter at night and despite my 747 landing lights cars often don't both erto see me.

Anyway, got to tyr it ou last night when a car stopped right I front of me half in the bike lane. So I let him have it with the new toy AND... he thought it was a cop, so he put on his turn signal and went totally into the bike lane and stopped, waiting for the cop/ambulance whatever to pass. I guess the sound this thing makes - which is a loud high pitch chirping - is so unfamiliar to motorists that they assume its some new type of emergency siren.

Tried it one more time later on the ride AND... same damn thing. Jokes on me. I'll just go back to screaming at the top of my lungs...

dehoov said:

Maybe a bit offtopic, but I just bought a battery (2 aaa's) powered horn, a little pricey but it promises 130dB at one metre, which is a jet engine (or an ACDC live concert) from 1 metre. It was pricey ($30) but I thought a good idea given I bike through the winter at night and despite my 747 landing lights cars often don't both erto see me.

Anyway, got to tyr it ou last night when a car stopped right I front of me half in the bike lane. So I let him have it with the new toy AND... he thought it was a cop, so he put on his turn signal and went totally into the bike lane and stopped, waiting for the cop/ambulance whatever to pass. I guess the sound this thing makes - which is a loud high pitch chirping - is so unfamiliar to motorists that they assume its some new type of emergency siren.

Tried it one more time later on the ride AND... same damn thing. Jokes on me. I'll just go back to screaming at the top of my lungs...

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Haha!! What horn is this that you bought?

Anyone know of a horn that might be compatible with the CA aux power? I'm interested in a horn for cars (I have a bell for pedestrians and other bicyclists) and was hoping that I could use this rather than having a separate system, Thanks!

Car horns take huge amounts of current, at 12V, for all the ones I have played with.

The pair I have on CrazyBike actually takes so much current that it causes quite a lot of sag on either 3s or 4s of EIG NMC 20Ah cells, and will dim the car headlight (which itself takes several amps).

I have yet to find any of the 12V (or rather, 14-15V) DC-DCs to get power for the horn out of my traction pack--a very few will sort of activate the horn a little, with a click or a squeak instead of a beep, just as they shutdown from overcurrent, but msot don't even do that and just shutdown (I think I killed a couple with it completely before I gave up and just run it off it's own battery).

Car horns are also usually fairly large, and the ones I've had come in pairs, detuned from each other so the chord or cacaphony they make is more attention-getting. Each one of the ones I have on CB2 is larger than my loosely-closed fist.

You can get 24V horns, and they'll take less current, but I don't know anything about them except that the ones I've had from "scooters" and an EVG bike aren't even as loud as a good bicycle bell. Pretty sure I sneeze louder than any that I've had, too. There are probably better ones out there than I've had.

Theres the airzounds I think it's called if you want a loud air horn. Never had one but they are well-spoken-of.

Just get a train horn and run it off your pack lol https://www.youtube.com/watch?v=icnRMW6P9nc

Or maybe just a ship horn https://www.youtube.com/watch?v=I9KKaj26Lsw

I have a small air horn running directly off my battery like teklektik had mentioned early, because as he had mentioned you only need your horn every so often. The air horn draws almost 8 Amps, but it is used for a second or less at a time and is only there in the need of an emergency when someone is getting ready to pull out in front of you which has happened a few times. I always enjoy the look on the peoples face as I pass them and have just scared the crap out of them because they weren't expecting it. Placed a photo below so you can see where I mounted mine. I think it is called the Wolo Bad Boy and has the compressor mounted directly to the horn so it is very compact, but still loud. I was able to fit it inside the rear rack so it takes up no room externally. The sound is a bit reduced because I have it under a plastic cover and to the back of the bike not the front, but the loudness completely makes up for it.

Ed