# Electronic – How to calculate the power dissipation in a transistor

bjttransistors

Consider this simple sketch of a circuit, a current source:

I'm not sure how to calculate the power dissipation across the transistor.

I'm taking a class in electronics and have the following equation in my notes (not sure if it helps):

$$P = P_{CE} + P_{BE} + P_{base-resistor}$$

So the power dissipation is the power dissipation across the collector and emitter, the power dissipation across the base and emitter and a mystery factor $$\P_{base-resistor}\$$. Note that the β of the transistor in this example was set to 50.

I'm quite confused overall and the many questions here on transistors have been very helpful.