Horn (buzzer) -CASA LAMBRETTA- Lambretta D & LD 150, Vespa V50, V90, VNB4T to VNB6T, VBB2T - Chrome

Casa Lambretta horn 6V, chrome - suitable for Lambretta D/LD 150 and Vespa V50/V90/VNB/VBB

AC/DC?

AC stands for alternating current = alternating voltage = buzzer
DC stands for direct current = direct voltage = horn

Schnarre
Many old vehicles without a battery use alternating voltage as the on-board power supply. 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 their 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 buzzer.

(US)