Derating curve

The derating curve describes the maximum permissible power loss of an electrical or electronic component depending on its ambient temperature .

example

An inverter automatically reduces its output (and thus also its power loss) due to excessive ambient temperature. The inverter protects itself from overheating. The background to this is that the dissipation of power loss under given operating and cooling conditions and increasing ambient temperature decreases linearly with the difference between component and ambient temperature.

practice

Typical derating curve

In practice, the power reduction and thus the derating curve is often not taken into account by the component or device itself, but is the task of the user, unless it was already taken into account during the development of the overall product.

Connectors

Plug connectors also have a maximum current that is dependent on the ambient temperature with which they can be operated. Since the power loss of a connector increases quadratically with the current, the permissible current intensity does not decrease linearly with the ambient temperature in contrast to the graphic above.

computer

In computers, heat sinks or fans are often used to remove the power loss z. B. to maximize the main processor . This prevents the derating curve from being exceeded by cooling.