horn

from Wikipedia, the free encyclopedia
Pneumatic horn of a fire extinguishing system
Horn ( Makrofon ) of an ICE 3 driving past at 300 km / h ( high-speed route Ingolstadt – Nuremberg )

A horn is a device used to generate sound signals. Depending on the design, it is operated either with electrical energy or compressed air.

history

The horn as an acoustic signal generator has been known for centuries. In English literature, the term "sound the horn" is used almost synonymously with ringing the doorbell.

In the early days of automotive engineering, horns were operated mechanically, known as ball horns. The horn was electrified in the mid-1920s, with many drivers still carrying ball horns with them. In a travelogue from 1928 Irene Rohan writes:

“When we continued our journey [...] it was often so steeply downhill that, with the engine off, we shifted into second, sometimes even first, gear, which reduced the use of the four-wheel brake to a minimum. The ball horn proved its worth here, as our electric horn was switched off with the motor. However, there is less honking in Switzerland than here, but driving more correctly. "

Road traffic

In Germany, Austria and Switzerland, a horn is generally required for motor vehicles with an engine of 50 cm³ or more, in order to be able to emit a sound signal in the event of danger and when overtaking outside built-up areas. In Germany this is regulated by § 55 of the StVZO . The sound pressure level of the horn must not exceed 105 dB (A) at a distance of seven meters. In addition, a series of sounds is prohibited in Germany, except for special signals such as the siren of the fire brigade or police.

In Germany and Switzerland, on the other hand, mopeds and bicycles must be equipped with a light-colored bell. In Austria, on the other hand, it is expressly permitted to mount a horn instead (in accordance with the Bicycle Ordinance and Motor Vehicle Act) and use it in accordance with the provisions for issuing acoustic signals. The German Road Traffic Act prohibits the attachment of horns to bicycles, but does not make any statement about the installation of a horn on the human body.

In Germany, according to Section 16 of the StVO , the horn may only be used to warn other road users of impending dangers or to announce one's own intention to overtake outside of town. Any other use constitutes an administrative offense in Germany , for which a standard rate of ten euros is provided in the catalog of fines .

In Switzerland you have to behave in road traffic in such a way that horns and light signals are not necessary if possible. You can horn or give light signals if traffic safety requires it. It is permissible to sound the horn if this can prevent an accident. You have to sound the horn when children z. B. play on the street and do not pay attention to the traffic and in front of confusing, tight bends outside of town.

In the mountains

In mountainous areas it is necessary and permitted to briefly emit one or two sound signals in front of bends that are not visible in order to warn oncoming traffic. As a result, an oncoming motorist can reduce his speed and prepare for oncoming traffic.

Fire protection technology

In fire protection technology , a horn is used to warn people present in fire extinguishing systems with gaseous extinguishing agents that the protected area is imminent or has been flooded with extinguishing agent.

Process control technology

In process control technology , a horn is used to indicate critical states when limit values ​​are exceeded (" alarm ").

Sports

Underwater horns serve as a signal generator in underwater sports, including underwater rugby.

functionality

Usual car horns work on the principle of the Wagner hammer or the impact horn . A steel membrane takes over the sound radiation and, together with a piece of iron that closes the magnetic circuit, forms the mechanical resonator . Its mass and the restoring force of the membrane determine the fundamental frequency . A horn is often installed for effective sound radiation . The shape and material properties of the steel membrane as well as the internal damping and the spring characteristic of the system determine the spectrum of harmonics and thus the sound character . Harmonics are mainly formed when the iron sheet hits the core of the electromagnet. Vehicle horns are designed for short-term use.

Alternatively, compressed air horns can also be used - especially if compressed air is available on board anyway, as is the case with trucks and buses. Compressed air horns work on the principle of the upholstered whistle or a valve that closes periodically due to the flow (see also Martin's trumpet , fog horn , clarinet ). Some devices have a membrane that detects the flow and closes the valve.

See also

Web links

Wiktionary: Horn  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. "An Antient Fragment." Times, October 18, 1786, p. 2. The Times Digital Archive . Web. April 13, 2018.
  2. ^ Das Auto-Magazin , July 1928
  3. http://www.verkehrsportal.de/stvzo/stvzo_64a.php
  4. Catalog of fines - No. 70
  5. VRV Switzerland Art. 29
  6. With the horn and caution: Driving on the mountain - STIMME.de. Retrieved June 10, 2020 .