What is the use of negative regulators
Under any circumstance the 7905 is unsatisfactory fro a + 5V regulator unless you are a skilled technician. You didn't damage it as it is protected for reverse insertion internally. Get am LM2940 it is a TO220 case regulator just like the 7805 but it will work down to a .2V I/O differential at low current loads... Under a .1 A load it's dropout voltage is 5.2 - 5.3 volts for regulated 5V out. The LM7805 or any '7805 requires 2.5V I/O or the input supply must be 2.5V greater than the output voltage i.e. 7.5V min in for 5V out... Batteries could be smaller (fewer cells) and last longer. 4 D cells would NOT work with a 7805 but would on a LM2940 and let you use nearly 75% of their capacity. With 5 cells you could use 90% of the batteries capacity but about 15 - 20% of the same batteries with a 7805... "From the LM2940 data sheet"...Doc
I may not comprehend the idea of negative voltage.. is that like negative water pressure, where it sucks out electrons rather than pushes?
@cjdelphi, retrolefty, you're answering the year old post.Discussion has been re-started by post # 7. Have at it with that one.