The DC/DC converter is an optional link. It is not to be found in every portable
product. There are two reasons for its presence. First of all, the battery might deliver
a voltage which is not suitable for operation of the load. Secondly, each circuit part
of the load should be operated from the lowest possible supply voltage for efficiency
reasons, because a surplus in supply voltage is often dissipated in the form of heat.
In both cases, the DC/DC converter powers the load with the lowest possible supply
voltage, irrespective of the battery voltage. The DC/DC converter uses an inductor,
which translates the electrical energy from the battery into magnetic energy and
back into electrical energy again. In the load, the electrical energy from the DC/DC
converter is converted into sound, light, Electro-Magnetic (EM) radiation or
mechanical energy.