What are efficiency and standby power consumption?

AC/DC Power Adapters — Desktop & Wall-Mount, clearly explains efficiency and standby power consumption in switching power supplies.

AC/DC Power Adapters — Desktop & Wall-Mount: What Are Efficiency and Standby Power Consumption in Switching Power Supplies?

Efficiency

Efficiency is defined by the input active power and output power, as shown in the following formula.

The ratio of energy supplied from the wall outlet (input active power) to the energy output from the AC/DC Power Adapters — Desktop & Wall-Mount (output power) is expressed here.

For example, if you exchange a 1,000 yen bill, receiving ten 100 yen coins would equal the original amount, but if a 100 yen fee is charged for the exchange, and you receive nine 100 yen coins amounting to 900 yen, the efficiency is expressed as 900 (output) ÷ 1,000 (input) × 100 = Efficiency: 90%

If the efficiency is 100%, it would be an ideal AC/DC Power Adapter — Desktop & Wall-Mount. However, achieving 100% efficiency is impossible due to internal energy usage and conversion losses.

The above specifications indicate compliance with Level V of the efficiency standards set by the CEC (California Energy Commission).

Compared to the exchange example, it may seem that the efficiency is quite low, but conventional transformer-type AC/DC Power Adapters — Desktop & Wall-Mount, which were mainstream nearly 20 years ago, typically had an efficiency of around 50%.
Since switching-type adapters became mainstream, efficiency has drastically improved, and most products now exceed 80% efficiency.

What Is Standby Power Consumption?

Standby power consumption defines the amount of power consumed in standby mode.
It refers to the power consumed even when the AC/DC Power Adapter — Desktop & Wall-Mount is plugged into a power outlet but not connected to any output.

This can be compared to a dripping faucet that leaks even when tightly closed.
While a properly sealed faucet does not usually leak, in the case of AC/DC Power Adapters — Desktop & Wall-Mount, it's technically difficult to reduce this power to zero. If absolutely zero standby power consumption is required, you'll need to take actions equivalent to turning off the main water valve, such as unplugging the AC/DC Power Adapter — Desktop & Wall-Mount or using a power strip with a switch to cut the power.

The above specifications indicate that the standby power consumption is 0.3W or less.

Leave it to us for high-efficiency AC/DC Power Adapters — Desktop & Wall-Mount and switching power supplies backed by extensive experience.

Related content