Modern electronic sirens with their current power output and sophisticated technological features could not come into existence without several advanced technologies. One of them is Class D amplifiers.

In general, an electronic amplifier is used to amplify an electrical signal from a source (such as a microphone, MP3 player, or a built-in radio) and then to transmit the signal of a required output to an acoustic transducer, usually pressure loudspeakers. In the past, this process was not ideal as classical A, B or AB Class amplifiers were relatively inefficient, i.e. most of the consumed electrical energy was converted into additional heat. As a result, the electronic sirens of the time still presented a significant technological advancement compared to the previous obsolete mechanical sirens; however, they remained uneconomical, consuming much energy, were quite a challenging task for designers regarding their cooling and waste heat transfer, and their electronics boxes were cumbersome.

Radical change was possible only after the introduction of modern Class D amplifiers. Their most significant advantage is the efficiency of electrical energy conversion, which is over 90%. Thanks to this, they can generate a signal of the same acoustic pressure consuming less energy. Therefore, they can work longer when powered from built-in batteries. The operational principle of a Class D amplifier is quite complex, so to put it simply, it is enough to say that its greater efficiency is achieved due to delta modulation when built-in transistors are either switched off or fully operational. This modulation prevents a transistor from being only partly conductive and converting the unused energy into massive amounts of heat. Less waste heat allows for the use of smaller coolers for its components, resulting in the lower weight, more compact dimensions, and also the lower production costs of the transistor. In critical situations, where the central power supply is cut off, this is a major advantage.

By using Class D amplifiers, it was possible to develop innovative products that had not existed until then due to weight or size limitations. Speaking of the Telegrafia portfolio, these are, for example, powerful, sophisticated Screamer and Bono sirens, and Pavian Car and Screamer Car mobile sirens. This type of AMP07 amplifier is also embedded in the Pavian and Gibon electronic sirens.

The development of numerous advanced technologies such as a Class D amplifier led to the current electronic sirens being lightweight, powerful, and efficient. Our development department is continuously improving our electronic sirens, making Telegrafia the world’s top brand.