Electronic – Power dissipation

powerpower electronicspower supplypower-dissipation

In electronics, we always calculate power dissipation of components and devices all the time. I understand why we do this (heat issues and power supply), but there is something I never really quite understood.

What normalizes this power we always calculate? By this I mean:

  • Is it like the "percentage" of the power used by a device "per watt" from the source?
  • Power used per second the device/component is operational?
  • If the device is battery-powered , percentage of the total energy of the battery it will drain?

Best Answer

Fraction of overall power used by a part of the device can be relevant. For example, this can tell you whether it's worth the complexity of turning off a particular subsystem when not in use.

Power per second makes no sense. Power is energy per second.

For battery powered devices, you want to calculate how long the battery will last, or conversely, what battery you need to last a certain time.