Experiment 15 - The heat generation of the LM317

Now what about the heat generation or power dissipation of the adjustable voltage regulator LM317...?

The voltage regulator LM317 is a so-called linear voltage regulator. Its internal design is similar that of the voltage regulators 78xx and LM2940. Hence the power dissipation P_D of the LM317 is also approximately described by the formula...

P_D = (U_in - U_out) × I_out

Circuit diagram heat generation voltage regulator LM317.

Circuit heat generation voltage regulator LM317. (Enlarge)

When pressing the pushbutton switch S1 in this experiment, both of the load resistor R3 and the LM317 heat up quickly!