yet another LDO 5V regulator

the Regulator :: /̲!̲\̲ this thing seems to perform better than LE50A (STMicroelectronics) , LM78L05ACM (National Semiconductor Corporation) , MC78L05AC (Motorola, Inc.) /̲!̲\̲ when powered by 9V 6LR61 alkaline -- in a sense of I_OUT/ΔU_OUT . . . . . . . . . history of :: the goal : steady supply for OpAmps powered from Lo-Power battery ►► everything is good as long as you have to implement the current limit . . . so this one has 1 unintentionally "built in" (adjustable by transistor-switch current source) ::

the actual transistor used for switch is ancient 2SD1252A (Panasonic)the custom zeners are random Red-LED + Д9К (apx. 2V + 320mV drop) other BJT-s are 2N3906(-04) but you can use a better ones such as fixed beta 2SA1015 , 2SC1815 ...

!note  :: altough theLE50 is labelled as "Very Low Drop" it actually performs worse than 1 of those 78L05-s and the all three b_a_r_e_l_y manage the 150Ω load with reasonable output (4.8 dn2 4.7V) . . .
 . . . when the brought regulator does 100Ω with about 10mV output-drop and acts similar to above 3 at about 26Ω with 175mV drop e.g. 4.83V output -- though /̲!̲\̲ it does not have thermal protection and it's current limiting is poorly studied /̲!̲\̲

[Eop]