The 13.5 volt (Vpp) is only a reference voltage, the PIC generates it's own internal
programming voltage. Therefore the current of 140 mA is drawn also from the 5V regulator.
(In reality it is less than 140 mA because some current is used by the programming LED).

The LM7805/TO220 Rja value is 50 °C/W and its TjMAX is 125 °C.
(Same as the LM317/TO220, see previous post).

The input voltage of the LM7805 is 13.5V (verify that) and the output voltage is 5V.
The voltage difference is 8.5V. (13.5V - 5V).

The current is 140mA when programming and 40mA when not programming.

When programming, the power dissipation of the LM7805 is:
8.5V * 0.14 = 1.19 Watt

When not programming, the power dissipation of the LM7805 is:
8.5V * 0.04 = 0.34 Watt

For the LM7805/TO220 the power dissipation is most of the time 0.34 Watt so
there is no need for a heat sink.


Luciano