Acoustic signaling devices are required on every vehicle. Their purpose is defined by the following range of applications:
■ An acoustic device used by the driver to alert outside people of the vehicle’s presence or,
■ An alarm device working as anti-theft system with the purpose of deterring intruders from the vehicle The electromechanical horn function is based on the oscillation of a diaphragm due to the magnetic field created by current flow through a copper coil body inside the horn. This diaphragm movement can be used in two ways:
■ Oscillator movement that creates a metallic sound (disc horns) or,
■ Air flow produce by this diaphragm movement is conducted through a projector creating an harmonic sound (trumpet horns) Depending on the respective environmental and traffic conditions different horn types can be used for sound penetration.
trumpet horns: wide spread of sound
Disc type and super-tone horns: Concentrated, far reaching soundElectromechanical Supertone Disc Horns
Horns and Fanfares
Electromechanical Small Disc Horns Disc horns are distinguished by their metallic “beep” sound with very high sound pressure level. They are used as a traffic signaling device (horn) as well as alarm signaling device. These horns are excellently suited for applications where it is necessary to satisfy sound level requirements with only one signaling device. It also is highly resistant to environmental conditions and frequent usage. The 80 mm diameter M28 model is available in 12 VDC version and the larger 97 mm M26 model is available in 12 VDC and 24 VDC versions. Super tone disc horns are suited to extreme conditions because of their higher pressure level that gives them even further-reaching penetrating power. This horn is ideal for large vehicles and aftermarket supply with its pleasing appearance and powerful sound and wide range of supply voltage versions. The 112mm diameter B36 model is available in 12 VDC, 24 VDC, 40 VDC, 80 VDC and 110 VDC versions with 400 Hz high frequency and 335 Hz low frequency. The 123 mm diameter B133 model is available in 12 VDC and 24 VDC versions and has 500Hz high frequency and 375 Hz low frequency types.4
Trumpet horns are distinguished by their robust “honk” sound historically found on North American and European automobiles. Trumpet horns are overwhelmingly preferred by end users in terms of sound richness. They are most adept for use as a traffic signaling device (horn).
Optimum performance and customer satisfaction in regard to the acoustic results come from a polyphonic sound – that is by incorporating both high frequency (500 Hz) and low frequency (400 Hz) in a single application. Hella offers two versions of small trumpet horns to address the problem of increasingly demanding weight, space and cost requirements. The motor or driver portion of either horn is identical; only the trumpet differs in each version: Electromechanical Small Trumpet Horns (80 mm)5 Technical Information Horns and Fanfares Electromechanical large trumpet horn (100 mm) Version 1: Vertical mounting With reduced thickness or profile, this horn was designed to install easily behind the grill of the vehicle in the vertical position. Its patented trumpet design reflects the sound 90 degrees with respect to a typical trumpet horn, thus reflecting the sound directly forward when mounted in the above mentioned position. Although designed for the grill location of the vehicle, it is ideal for any occasion which requires a slightly decreased packaging space. Version 2: Standard version for horizontal mounting The standard trumpet design is optimized for acoustic performance including sound pressure level, resulting in a slightly larger profile than that of the reduced profile 90 degree trumpet. Comparatively, the direction of sound output is at the 0 degree position. Large trumpet horns feature a richer timbre than that of the small trumpet horns meaning that with identical sound level and frequency, a larger horn sound spectrum contains additional higher tones that result in a “fuller” sound. The 100 mm diameter large trumpet horn TE12 model is available in 12 VDC and 24 VDC versions and 500 Hz high frequency and 400 Hz low frequency types.6
A wide variety of standard and special connectors, both sealed and unsealed, are available from typical blade terminal connection to USCAR compatible connectors with the capability to power two horns (low and high) from a single connection. Two-way (+ and –) connection as well as one-way (+ only), with grounding through the bracket are available for all horns. A wide variety of horns brackets can also be supplied to fulfill customer expectations in applications where space available for horn mounting is very tight. The Hella product line engineering offers ad-hoc design solutions to solve any demanding mounting situation.