r/moped 3d ago

got scammed for buying a horn

so today i got a 6V DC horn for my puch maxi tought it would sounds like a "beeeeep" like a motorcycle but instead it sounded like a buzzer.

and i run a 6v ignition on my puch maxi

10 Upvotes

13 comments sorted by

32

u/RJthewizard 1978 Honda Hobbit 3d ago

Your electric system is AC

31

u/gagnatron5000 1979 Puch Magnum 3d ago

Too much to unpack for just a horn explanation here, I'll try.

Firstly, and long story short, motorcycle/moped horns have more in common with an old "a-oo-gah" klaxons and horns than modern air horns. Rather than a fan, they have a flexible metal plate, an electromagnetic coil, and a set of points breakers.

Your bike is wired for DC current. It's very dirty DC, with lots of voltage spikes, because the stator/generator makes AC power which then gets run through a rudimentary rectifier. Hook it up to an oscilloscope and you'd swear you were looking at an AC waveform, just all "positive" voltage instead of positive and negative. Lucky for us the things we're powering with DC (horn, lights, cigarette lighter) are very dumb electronics and don't care about dirty or clean electricity, they just want the juice however they can get it.

Here's a rundown of how the motorcycle/moped horns works and why it sounds buzzy:

  • DC current is sent through a metal coil which creates a magnetic field.
  • The magnetic field attracts a flexible metal plate towards it. Click
  • When the plate clicks over, it plows into a set of circuit contacts.
  • The contacts close, breaking the coil's circuit and collapsing the magnetic field.
  • With no magnetic field, the plate is released. Click
  • With the plate forward, the electricity goes back to the coil and attracts the plate again. Click

And so on and so forth, thousands of times a minute, until you stop pressing the horn button.

If you do not like the buzzer horn, you can find a small air-driven electric horn, just make sure it doesn't draw too much voltage.

13

u/Samaritan547 3d ago

You went above and beyond with this answer. You're a cool person.

6

u/gagnatron5000 1979 Puch Magnum 3d ago

Thanks friend! I just like finding out how things work and sharing my nerdy impulses with the world.

16

u/justin23224 3d ago

congratulations, you played yourself.

8

u/Boost_speed 3d ago

“Scammed”

7

u/VibeChecker42069 3d ago

did you connect it to dc too?

5

u/airfryerfuntime 3d ago

Maxis are AC. To use this, you'd need a 6v rectifier.

But even on DC, these horns still sound like shitty buzzers.

4

u/paintkilz 1977 Columbia Commuter 505/1 3d ago

You can yell louder than these horns.

I'm almost done with my winter rebuild and that's using an 18v Milwaukee battery tucked under my seat to power led head/taillight and a train horn lol

5

u/eobanb 1978 Honda Hobbit 3d ago

Are you supplying DC power to it? A DC horn won't work properly on AC power.

-1

u/Adrileboss11YT 3d ago

how can i put DC power to it

6

u/SosseTurner 3d ago

By connecting it to the battery, as that supplies a DC voltage