Horn (buzzer) -OEM QUALITY 12V AC- Vespa GS150 / GS3, GS160 / GS4 (VSB1T), SS180 (VSC1T), VBB1T, VBA1T, VLA1T, Motovespa 160 GT - Chrome

)AC/DC?

AC stands for alternating current = alternating voltage = snare
DC stands for direct current = direct voltage =

hornSchnarre
Many old vehicles without a battery use alternating voltage as the vehicle electrical system. Only so-called buzzers can be connected to this. These are recognizable by a pitch that rises and falls with the engine speed.

horn
Due to the non-constant frequency, buzzers were no longer approved for use in German vehicles from around 1980 onwards. At this time, most vehicles were equipped with a battery and a DC electrical system. This is where the real horns, recognizable by a constant pitch regardless of the engine speed, are used.

Exceptions
There are a few exceptions where a DC horn was used despite the AC electrical system. From 1984, with the introduction of the Lusso series, Piaggio used so-called horn rectifiers. Here, a special bridge rectifier with downstream capacitors, which is only responsible for the horn, converts the AC on-board power supply for the horn into DC. This rectifier can also be retrofitted to all vehicles with a 12V AC vehicle electrical system if, for example, the TÜV does not accept a snare

(US)