These days many products are going green. They are very stringent regulations in place nowadays in Europe regarding all types of electronic products. These regulations govern the maximum power consumption while devices on standby mode. It is surprising to realize that just in the United States, all televisions combined in standby mode require a full nuclear power station to operate. That is because of how much power is wasted by electronic products. Aside from standby power, the power efficiency of devices operating is also crucial for reducing power consumption. Therefore, manufacturers have worked hard to improve the power efficiency of their products. In fact, many customers nowadays are looking at power efficiency rating of many appliances before making a purchase.
Let me look at wireless speakers from Amphony as an example of how manufacturers can improve power efficiency. These speakers integrate a power amplifier. Most of the energy which is wasted by wireless speakers is wasted inside the power amplifier as well as the power supply. To improve efficiency, manufacturers of these types of wireless speakers are nowadays typically using switch mode amplifiers as well as switch mode power supplies. These types of circuits have much higher power efficiency then linear products. Let me explain what I mean by that. A typical linear power supply consists of a transform a, a rectifier as well as a buffer capacitor. At its output is a voltage stabilizer. This type of power supply has fairly high losses due to the difference in output voltage after the voltage rectifier and the voltage stabilizer. Therefore, significant heatsinks are usually required for these types of power supplies. Also, there’s a fair amount of loss inside the transformer.
Switch mode power supplies on the other hand are really small and have very good power efficiency. However, even though the power efficiency of these power supplies is fairly high, they sometimes still have problems meeting the power requirements in place nowadays for standby power. That is because the power stage inside these power supplies is constantly working and thus draining power. In addition, the speakers themselves also require power in order to run the wireless receiver. Speakers are usually designed to wake up as soon as a valid signal is received. In order to monitor the wireless activity, the wireless receiver has to be active. However, it can be toggled between on and off so that it will not continuously monitor but rather monitor in intervals thus reducing power consumption.
The power amplifier inside the speaker also requires a fair amount of power. Therefore, in standby mode speakers usually totally disabled the power amplifier. Therefore the switching stage inside the amplifier does not work while the speaker is in standby. Only combining all of these mechanisms enables producers of wireless speakers to meet the stringent power requirements in place nowadays.