Hi, today I used 79L05 as the negative electrical level. The output filter capacitance is very large at first, just like the figure below: It is -12V. Under this condition, the chip is very hot,and the output voltage is just about -2V. I changed the 220uf to 47uf, then the chip worked well and the output voltage was at -5V without heating. I wonder why? Sorry for my poor English, but can anyone answer me? Thanks very much!