fish@ihlpg.UUCP (Bob Fishell) (08/23/85)
*** AC T YOUR AGE ***
Some time ago I posted an article on how to build a LOUD horn, mainly
out of components available at your friendly local Radio Hack. With
all the flack about obnoxious motorists lately, I thought I'd recap the
article. A LOUD horn can help in traffic, believe me. It's saved my
butt a couple of times.
Parts List:
2 12-V buzzers. These are the round variety, made of steel, with one
wire and a bracket on the back. The original recipe called for 6-V
buzzers, but Hack don't carry 'em any more (thanks to the netter who
pointed this out to me; sorry I clobbered your letter before I got a
chance to reply). The 12-Volters work just fine.
2 9-V battery clips, like those used in cheap transistor radios.
2 9-V radio batteries, preferably alkaline. The carbon variety are a
couple of grams lighter (for those who really care about that sort of thing),
but won't last as long.
1 normally open, SPST, momentary switch.
Electrical connections:
__buzzer__
bike | | bike
frame-----| |---( - battery +)---( - battery + )---switch---frame
|__buzzer__|
Mechanical assembly:
Depends on what you've got lying around. I made mine out of chassis parts
from old TV sets, but any of several materials should do. The buzzers
have clamps in the back that will admit a rectangular brace about the
size of a popsicle stick. I made one such brace out of an aluminum
rail. I clamped the brackets down on either side and drilled a 5/32"
hole on the middle. This mounts the buzzer on the front reflector
tongue, but don't do it yet.
I made a little basket out of strips of sheet metal. It's just the
right size so that the two batteries sit snugly side by side in it.
I taped the batteries together so they can be removed as a unit.
Another 5/32" hole is drilled in the center of the basket's front.
The basket goes behind the reflector tongue, and both the basket
and buzzer assembly are mounted with the same screw.
The parts I used are decidedly nonstandard, but I think you could use
mending plates quite satisfactorily.
Wiring:
The buzzers only have one wire coming out; the body serves as the
other connection. These are automatically grounded to the bike
frame if you use all-metal parts, but you'll have to run a ground
wire if you use plastic. Solder both the wires to the negative
pole of one battery clip. Solder the positive pole to the negative
pole of the other one. Solder the other's positive pole to a wire
about 20" long leading to one side of the pushbutton switch (see
drawing). Ground the other side of the switch to the bike frame.
All connections should be secured with heat-shrink tubing.
DON'T use electrical tape, because it gets gooey in a hot sun.
My button is mounted on the handlebars just to the right of the stem.
Tuning and operation:
The buzzers I used can be changed in pitch by turning a screw
in the back. I chose two frequencies that beat together rather
unpleasantly. The noise they emit is thin and metallic, but very
LOUD. It is so obnoxious that I don't use it on joggers or other
bikes (unless they're wearing headphones) that I'm just trying
to pass, but it gets attention QUICK in an emergency. The horn
is LOUD enough to be heard clearly by a teenager in a closed,
muffler-less Camaro with the radio blasting, and LOUD enough to
hurt your ears if you blow it inside the house. I use it mainly
on motorists, most of whom turn their heads in surprise at the
decibels this mother produces. Serves 'em right, too.
__
/ \
\__/
Bob Fishell
ihnp4!ihlpg!fishreid@Glacier.ARPA (Brian Reid) (09/06/85)
A number of years ago I built the loudest damn bicycle horn you ever saw. I went to a photo store and bought a Falcon Dust-off setup, which has a can of freon and a trigger that squirts freon out a nozzle. I then went to Sears and bought a little boat horn that was intended to be powered with compressed air of some kind. The boat horn screwed right into the Falcon nozzle--same 1/4 npt threading. I then mounted the whole thing in the waterbottle cage, with the horn pointing up and to the rear, and ran a control cable from it to a Sturmey-Archer 3-speed gear trigger. The control cable attached neatly to a little hole in the Falcon trigger. The resulting horn was louder than your average Mack truck; it made a "supersound" seem like a bird chirping by comparison (also it was about 3 octaves lower-pitched than a supersound). It was stolen about a month later, and I never got around to building a replacement. I think if I had it to do again, I'd mount the boat horn on the handlebars and run pressure hose from the freon cannister up to the horn (this kind of pressure hose can be bought in the tool department of Sears--it's used for attaching spray guns to electric air compressors). -- Brian Reid decwrl!glacier!reid Stanford reid@SU-Glacier.ARPA
kds@intelca.UUCP (Ken Shoemaker) (09/07/85)
> A number of years ago I built the loudest damn bicycle horn you ever saw. I > went to a photo store and bought a Falcon Dust-off setup, which has a can of > freon and a trigger that squirts freon out a nozzle. I then went to Sears > and bought a little boat horn that was intended to be powered with > compressed air of some kind. The boat horn screwed right into the Falcon > Brian Reid decwrl!glacier!reid > Stanford reid@SU-Glacier.ARPA Actually, I think you can buy things like this already made. I think their intended use is for women who aren't keen on carrying mace to frighten off would-be attackers. I don't know the decibal difference, though I would think it wouldn't be quite as loud, but very loud, nevertheless, and small and probably pretty cheap. -- ...and I'm sure it wouldn't interest anybody outside of a small circle of friends... Ken Shoemaker, Microprocessor Design for a large, Silicon Valley firm {pur-ee,hplabs,amd,scgvaxd,dual,qantel}!intelca!kds ---the above views are personal. They may not represent those of the employer of its submitter.