Simple voltage regulator

This is a very simple (quite primitive) voltage regulator. Any short-circuit will immediately destroy the NPN, a fuse on the output will not be of any help, as fuses are far too slow to protect transistors.

Uout [V] = Udz [V] - 0.7 [V]
R [Ω] = ( Uin [V] - Udz [V] ) ÷ 0.01 [A]
Pt [mW] = ( Uin [V] - Uout [V] ) × Iout (mA)
C = 22 µF

For example, to obtain a 4V / 500mA regulator from a 9V source, we will need the following elements:

R - 430 Ω
C - 22 µF
Dz - Zener diode 4V7
T - NPN 10V / 1A / 2.5W