martin clark
pinko bodger
You can try these two items together:
1) reduce input filter from 10/3u3 to 1K / 47uF electrolytic (reduces voltage drop here)
2) Change 7812 to 7809.
This is very marginal - if the drop-out voltage across the 7805 is less than say 2.5v then you may just need to bypass the input filter. Try a 10ohm resistor instead, so that the input to the 7809 is fed form your available 15v supply by 10ohm/47uF (or larger cap)
1) reduce input filter from 10/3u3 to 1K / 47uF electrolytic (reduces voltage drop here)
2) Change 7812 to 7809.
This is very marginal - if the drop-out voltage across the 7805 is less than say 2.5v then you may just need to bypass the input filter. Try a 10ohm resistor instead, so that the input to the 7809 is fed form your available 15v supply by 10ohm/47uF (or larger cap)