07-03-2015, 16:07
It seems difficult to convince you that even with a fast change in the input voltage the output voltage of the regulator must remain constant.
Probably your 7809 regulator is damaged, if I remember, at some point you had connected the 7809 with a load, but without connecting the GND pin. This certainly damaged the regulator.
Probably your 7809 regulator is damaged, if I remember, at some point you had connected the 7809 with a load, but without connecting the GND pin. This certainly damaged the regulator.

